Thursday, December 18, 2014

Some Unusual, Non-UV Photochemistry

Recent articles have highlighted a couple of unusual photochemical phenomena in living animals. While your thoughts might be that the photochemistry is UV-induced, neither one does in fact depend on UV radiation.

The first was a report from a few weeks ago (Original article ($) - C & E News coverage (open access)) regarding humans that can see near-infrared (NIR) light. The researchers found that what was occurring was 2-photon absorption, a phenomenon I've discussed before (1 and 2), where 2 NIR photons, each with half the energy needed to cause a photochemical reaction, both activate the same molecule at the same time (or more accurately, within an acceptable time window). I'm not sure of the practical applications of this and I don't think I'm enabled to see NIR (I've been deep in mines with any lights on and the blackness is incredible. I never had any hints of NIR coming off my companions), but this is still pretty intriguing. I'm sure the military is already looking into applications.

Meanwhile back in the realm of the visible light, such light is usually thought of as being pretty innocuous, at least at the fluxes we experience in our normal lives. But it turns out that certain insects are susceptible to damage by blue light (open access article). These include fruitflies, mosquitoes and flour beetles. And this is not the result of exposing the critters to some souped-up light bulb that burns out 100x the normal amount of visible light. No, this was run with with fluxes that are the equivalent to those found outside the researchers lab in Japan.

Further, the researchers found that the wavelengths for maximum lethality varied with species. Maybe this is surprising for biological systems (or maybe not), but I've made the point repeatedly on this blog and in presentations that polymer degradation rates are wavelength dependent and show a peak at a unique wavelength. So this is yet another case of us duplicating nature (even if we didn't know it at the time).

I can't help but think that this might be a good part of the reason mosquitoes are never active in bright light, preferring to come out and attack in the deep woods during the day or anywhere else at night. I don't think the kill rate with blue light is fast enough to make this discovery into an effective alternative to DEET, but I know of one local organization with a $17 millions budget that should look into this for dealing with the critters here in the Twin Cities.

Previous Years

December 18, 2013 - Nitrile Gloves Are Not The Universal Glove!

December 18, 2009 - Some subtle, subtle surfaces

Tuesday, December 16, 2014

About that Night I Spent in Jail...

Ah yes, Christmas break in 1983. I remember it well. But the story starts well before that.

Some 17,000 years ago when the glaciers retreated from Minnesota for good, they had scrapped the Canadian Shield pretty thoroughly, leaving a tremendous number of lakes in the Northeastern part of Minnesota and also the Southwestern parts of Ontario. The Ojibway discovered that the area was fabulous for canoeing. Since the distances between lakes were short it was easy to carry canoes and such between them, allowing for longer trips to be made. European explorers took advantage of the same routes, as did the fur trappers that followed. While most people think that the history of western civilization in North America in the 1600's was mostly along the coasts, there were in fact trappers and others in this area some 2000 miles away from any coast. In pursuit of beaver pelts, they would travel up the St. Lawrence river, through the Great Lakes to an outpost now called Grand Portage, and then head inland via the some of the lakes I just described. The most common route went towards Lake of the Woods and this route is in fact what now forms the eastern portion Minnesota-Canadian border. [*]

Civilization never made too strong an entry into the area and so in 1978, the Boundary Waters Canoe Area Wilderness Act became law which over the course of the next few years increasingly outlawed motors in the area, known as the BWCA for short. Boats were first to be outlawed while snowmobiles could continue to operate through 1983. The locals were plenty upset about having their motorized access taken from them, although over the last decades, things have gotten better. Ely has grown and embraced the numerous tourists that come in every summer and in the other seasons as well.

In my youth, I was active in the Boy Scouts and would go wilderness camping as much as possible. Since the Boundary Waters was about 5 hours from home, my brothers and friends would go there often. Mostly in September. Due to the University of Minnesota not starting until the last week of September, we could quite our summer jobs and go canoe for a week or 10 days. Since it was after Labor day, the area was practically abandoned and best of all - no mosquitoes!

During our trip in the fall of 1983, I was with my friend Eric on Lake Kekekabic. He suggested that we ditch the canoes and walk up the hills on the south shore of the lake to see how progress was going on the new Kekekabic hiking trail. We did this and by sure luck stumbled up the Kekekabic ranger cabin. It was empty and unlocked, but that got the wheels turning...We marked the spot on our maps and began plotting. A group of us had been wanting to go camping in the winter in the Boundary Waters, so we saw this a great opportunity. The cabin was about a 1-1/2 day trip from the nearest road end, so we figured we could ski in, spend a few days at the cabin and ski back out.

So on Boxing Day, 1983, me, two of my brothers (Mark and Paul) and 3 friends (Mike, Eric and Bill) set off for a 6-day trip, planning to come back out on New Year's Eve. We had all done winter camping before but only for short trips or 2 or 3 days. This was a much bigger undertaking. The map below shows our intended route: put in at Moose Lake, work our way over the portages to Knife Lake and then down to Kekekabic. One bonus of this route was that we could stop in to see "Knife Lake Dorothy", someone we had never met but we knew of her legend. She had run a resort on Knife Lake for decades. When the BWCA was formed, her cabin was "grandmothered" in and she was allowed to stay put until her death. (The Wikipedia article shows how much authorities kept trying to push her out, but she fought on and never conceded.) She was famous as the root beer lady, selling homemade root beer to canoeists in the summer. So we stopped by on the way out, sharing some ice cream with her that we had brought on the trip. (Yes, it was cold enough that winter to keep ice cream frozen.) She told us she wasn't overly concerned that snowmobile access ended later that week. She had lived there so long that she really didn't really rely too much on people from Ely providing supplied via snowmobile. And besides, she had a battery-powered 2-way radio if she ever got into real trouble.

We said goodby, headed on to the ranger cabin, and moved in. We got the woodburning stove going and got comfy even if the lack of electricity made it pretty dark. Breaking trail through waist-deep snow on the portages and dealing with slush on the lakes had made the trip to the cabin take the all of 3 days, so we were happy for some creature comforts. Since the trail was already broken, we figured we could make it back to the car in 2 days so we planned to break camp on the 30th. That morning, we fired up water on the camping stove for making a big batch of oatmeal. Unfortunately, in the poor light and somewhat cramped conditions, I knocked the water pot off the stove and onto the leg of Mike. Mike was only wearing his long underwear at the time...

Time to get technical and bring plastics into the discussion. Polypropylene was used back in 1983 and is stilled used to make terrific long underwear for active lifestyles as it doesn't absorb water (unlike cotton). It's also is good and insulative. If you are winter camping, that is a good thing, except when you have a couple of quarts of boiling hot water on one side and human flesh on the other. Mike got the underwear off ASAP but he had already gotten blisters and was in a good deal of pain.

After about an hour or so, we realized that Mike would have had a difficult time skiing out, so we decided Mark, Eric and Bill would ski back to Dorothy's and use her radio so that we could get Mike out on a snowmobile. I stayed behind with Mike and my brother Paul. Within a surprisingly short period, the absolute silence of the wilderness was spoiled by the sound of snowmobiles. The group had made it to Dorothy's and as luck would have it, 2 forest rangers were there talking with Dorothy and stocking her up with supplies. They took our well broken trail and got to the ranger cabin in a snap. But they also looked at Mike's leg and realized that in the rough terrain over the portages, he was not going to be well off so they made the decision to fly him out. They called in a Forest Service ski plane from Ely which arrive in a short time. The plane had room for 3 passengers, so Paul and I hopped on as well.

We got to Ely and Mike went off to the clinic for treatment. And that is when we realized we had a problem. The other three people weren't going to be coming out until tomorrow and yet Mike, Paul and I needed a place to stay that night. Ely in 1983 was not setup for overnight guests, particularly in late December. There was no room at the inn as there was no inn open for business. Afterall, who would want to stay in a motel in Ely in late December? The car was 20 miles away and even if we got there, we didn't have the keys (they other guys did). And so they put us up in the only spot they could - the jail.

The jail had 4 cells each with one bed. I still remember this horrible revulsive feeling while being shown my cell by the officer. They didn't lock the doors, but still just that feeling from seeing the bars and the toilet and the bed...I hope I never feel it again.

The next day, Mark, Eric and Bill came out off the wilderness and bailed us out picked us up. They had had a terrible last day coming out because that day, December 31st, was not only the last day that snowmobiles were ever allowed into the BWCA, but it was also the opening day for lake trout fishing, and so everyone was taking advantage of the situation. They were all heading in while our group was trying to head out.

The trip home was thankfully uneventful. Mike was ok as the burns were limited to 2nd degree and just required regular cleaning and topical antibiotics. I've seen him since and he jokes about getting into hot water fights. I still feel bad about my flying elbow causing so many problems for all of us. I've not been back to the "scene of the crime" since, but my brother Mark has. The cabin is now padlocked and there is a "No Trespassing" sign.

No surprise there. No surprise at all.

[*] The western portion of the border is a different story. The original border was based on a faulty map (it's not the first time that's happened) that showed the Mississippi river starting up in Canada when in fact it starts quite a bit further south. The border was supposed to go along the voyageurs route and then go due west from the northwestern corner of Lake of the Woods until it hit the Mississippi. The error was soon discovered and so they changed the border by drop south from that same corner of the lake to the 48th parallel, and then proceeded west to the Pacific. As a result, Minnesota is the northernmost state in the lower 48. Also as a result, there is part of the state that you cannot access by land except by going through Canada.

Previous Years

December 16, 2103 - What does EPDM stand for?

December 16, 2101 - The Real Danger in Polycarbonate (it's not BPA!) and a Solution for it

December 16, 2100 - PLA that acts like ABS

Friday, December 12, 2014

Bette Midler: "She doesn't let plastic in her house"

Bette Midler was making some outlandish statements recently (it's not as if that is news), and as you might expect, plastics got in the crossfire:
"She doesn’t let plastic in her house."
That's pretty amazing. I wonder what strange materials she has in her bathroom. Start with the toilet seat. While most are plastic, wood ones are available. Having sat on bare wood toilets on more than one camping trip, I think we can safely assume that she would not subject her derriere (or the derriere of houseguests) to splinters that could be challenging to removed. But the wood can't be painted, since the paint has plastic in it. It can't have a urethane or acrylic coating either for the same reason. Shellac or another biobased coating would be a possibility. Maybe she has metal toilets with no seats such as in prisons?
I've never used such a facility (not even on that one night I spent in the Ely, MN jail [*]) but I can't imagine it would,

No Bette, there is plenty of plastic in your house and you let in all kinds of it whether you realize it or not.

[*] There's a long story behind that night. It involved no illegal activity and the cell door wasn't even locked. But that's another story for another time. And come to think of it, there is a plastics angle to it. Some maybe next week...

Previous Years

December 12, 2013 - Some Goofy Thoughts on Plastic Bags Being Seized

December 12, 2011 - The Future is Clear

Wednesday, December 03, 2014

Glove choice - it does matter

I missed this over the Thanksgiving week, so I'm assuming others did too. I've been adamant over the years (1, 2 and 3) about not just grabbing the nitrile gloves because they are readily available and because of their resistance to a broad range of chemicals. That range is broad, but not broad enough. Since different polymers and rubbers are soluble (or swellable) in different solvents, you need to be prepared to use different gloves in different situations.

Jyllian Kemsley in the C & ENew Safety Zone blog reposted this photo showing what can happen with the wrong gloves are worn:
"The organic solvent dichloromethane carried 3,4-ethylenedioxypyrrole through this researcher’s nitrile gloves. The compound polymerized onto the person’s fingers, forming poly-3,4-ethylenedioxypyrrole, a blue-black conductive polymer of unknown toxicity."
(The large number of conjugated double bonds absorb the short wavelengths and give the polymer its blue/black color, typical of many conductive polymers.)

Before you glove up, either refer to the MSDS (yes, they really do have useful information at times like this) or any of the manufacturer's compatibility charts. This page has a link to most of the manufacturers (scroll down to find them). There is no excuse for these types of images to ever occur (although it is going into my archive, since I'm sure I'll be repeating this warning in future. Sadly.)

Previous Years

December 3, 2013 - Dow Chemical to Drop the Chemical, in both Word and Deed

December 3, 2012 - The Return of the "Perfect Polymer"

December 3, 2010 - Reviewing a Paper - Round 2

December 3, 2010 - Bridgestone Cutting Rubber Usage

Tuesday, December 02, 2014

Post-Thanksgiving Hangover

It was quite a Thanksgiving weekend for me, so I'm behind on a lot of things. Consequently, today's post is pretty simple and quick to get out.

  • The British website Sciencecraft published a Q & A with me on Friday. Since I'm sure many Americans were out shopping for Black Friday specials and dozing off after eating turkey sandwiches, you might have missed it. I was asked a lot of wide-ranging questions and gave back even more wide-ranging answers, so I'm sure someone will take issue with something I said.
  • It's been about 6 months since we last were told that peer reviewers are being overworked and so we're about due for another opinion piece on the matter. Sure enough, here's the latest of the same-old-screes, in Nature of all places. As I've said in the past, you could use industrial researchers, since they outnumber academic researchers by 20-to-1 or some ridiculous number and they are largely untapped. Maybe it's time for a letter to the editor.
  • I will need to dig further into this one as it looks interesting, but the Daily Mail has an article relating pasta and polymers. Not the standard comparison of spaghetti and linear polymers as you might expect, but a new pasta shape, anelloni and polymer rings. While polymeric rings are nothing new, the modeling performed for this work shows that extremely large rings become entangled and glassy. The article is pretty poorly written so I'm not going to read too much more into it until I can track down the original research report.

Previous Years

December 2, 2011 - The Teacher Can Make All the Difference

December 2, 2010 - Think It's Obvious? Prove It.

December 2, 2011 - Adieu Hercules

Wednesday, November 26, 2014

Plastics and Thanksgiving

Tomorrow is Thanksgiving Day here in the US and so it will be pretty quiet on the interwebs. Friday won't be much better as many people have that day off too. Last year at this time I blogged about the netting around turkeys and how much underappreciated that product is. If you didn't read it last year, I would suggest you take a look.

This year, I'll keep it short and just mention that the American Chemical Council's blog has a great overview of how polyurethane is used in creating the giant balloons used in the Macy's Thanksgiving Day parade. (As well as a few other examples of how polyurethanes make the day more enjoyable.) It's worth a look. And making those balloons would be one cool job to have.

Previous Years

November 26, 2012 - Fantasy Images of the Great Garbage Patch

Monday, November 24, 2014

Me? An Invited Speaker? Oh, never mind

There isn't much to report yet on the job search front yet, other than this invite I received via LinkedIn:

The email was entitled Plenary Speaker Invitation: Green Chemistry-2015. Gee, that's nice, but then I read the body of the email:
"Dear John S,

We certainly don’t know each other; still, I would like to contacts
[sic] you and open a dialogue about, "2nd International Conference on Past and Present Research Systems of Green Chemistry" (Green Chemistry-2015), scheduled on September 14-16, 2015 at [sic] Florida, USA.

The main theme of the conference is “Foster Advancements in Globalization of Green Chemistry". The Organizing committee would like to invite you as a Speaker/Delegate for the conference."
There were some links and then it was signed by a person with an Anglo-Saxon name.

Of course, alarm bells immediately went off. When are spammers going to learn that grammatical errors in "professional" communications are a huge tipoff? First there is the subject/verb disagreement in a simple sentence, and then there's the misused preposition (always guaranteed to trip up non-native English speakers). There was also the nice sleight of hand, demoting me from "Plenary Speaker" to speaker/delegate in just a few lines.

Now I know English is a tough language to learn and I am more than willing to forgive errors (I need plenty of forgiveness myself) but the errors were enough to make me question everything. A little bit of digging and I found the conference to be organized by the infamous OMICS group, which was recently accused of running predatory conferences. You can read more of their tactics here and here.

So while it is is flattering to receive an invite, I will decline. As in ignore it. All of this further supports why I really don't put a lot of time and effort into LinkedIn.

Previous Years

November 24, 2010 - Corporate Cultures

November 24, 2010 - That's all for this week

Friday, November 21, 2014

Dow Chemical and Third Point reach a ceasefire

The Polyurethane Blog is reporting that Dow Chemical and Dan Loeb, the activist investor and operator of Third Point LLC., have reached a ceasefire. Loeb will lay down his weapons for a full year including taking down his flashy website [1]. On the other side, Dow will add to the Board of Directors the two candidates that Loeb wanted plus two more directors. Since the current Board of Directors is the CEO Liveris and 9 others, there will now be a 14 directors total. If Loeb had won the proxy fight, his 2 directors would have been 20% of the board. Now he has to be content with 2 out of 14 (14%). That's called dilution.

So we shall now wait and see if the ceasefire holds [2]. It is possible that the board may start causing issues for the CEO, although it is doubtful we will ever find out much about such internal fighting unless the new guys decide to kiss-and-tell. The old board members are probably too loyal to cause much trouble. Such is the case whenever the CEO is also the Chairman of the Board, which is pretty always the case.

[1] Yep, the site is totally gone. 404. Not even a note saying that the site was taken down.

[2] So now what I am going to blog about, especially regarding Dow Chemical? Geesh, Loeb was great for providing bloggable material. Well, there are the ongoing appeals over the price-fixing scheme that Dow was found guilty of. They are now trying going to the Supreme Court (lots of luck with getting them to take the case).

Previous Years

NOvember 21, 2011 - Throwing Away Books

Wednesday, November 19, 2014

Plastics to Oil? Not in my backyard!

Efforts to convert plastics to oil have been getting a lot of good press lately. People seem to like the ashed-to-ashes, dust-to-dust approach of taking petroleum-based plastics and turning them back into oil. (This is all done via the miracle of anaerobic pyrolysis, and the output is a very sweet oil since there is very little or no sulfur in the feedstock.)

But the fly in the ointment seems to be the same issue faced by any chemical plant: where to build it? And we all know the answer - not in my backyard! That was what happened in Smith Falls, Ontario the other day. Attendees at the Town Hall were 21-1 against the proposal. The facility would only process polyethylene (both high- and low-density) and polypropylene, both of which are pure hydrocarbons, so I'm not sure what the concerns are from residents "...about the possibility of a fire at the plant which they said, could potentially expose residents to toxic fumes." Pure hydrocarbons burn pretty cleanly, especially compared to say, PVC (which inherently gives of hydrochloric acid), polyurethanes which can give off isocyanates, etc.

While Canada is a net exporter of oil, eastern Canada has some gaps in its pipelines with western Canada and so the east has to import some oil. Hence the potential use for a project such as this. Putting such in a facility in say, Edmonton would be the equivalent of setting up an ice factory in Fairbanks, Alaska.

I wonder how much a similar project here in the US would face similar resistance. We will find out as this trending technology will not disappear anytime soon.

Previous Years

November 19, 2013 - Your Plastic Waste is Valuable

Tuesday, November 18, 2014

Wait, you lost this too?

This appears to be the week to lose things. I lost my job, the only known sample of ε-polypropylene was lost and now the world's smallest 3D-sculptures are lost too. Granted, these sculptures would be pretty easy to lose. Take a look at one:
There are additional pictures in the linked article.

These sculptures were made with 2-photon absorption photochemistry, although the details are sadly lacking in the report. You start with a volume of photoreactive monomers such as an acrylate. UV light will polymerize the liquid turning them into a solid, but the problem with using UV light is that it will polymerize everything along the path of the light beam from the outside in. To selectively polymerize just a certain volume of material that is located well inside the mass of liquid, you need to a 2-photon absorption. Take a beam of photons each with half the energy of the UV light and send them into the sample at right angles to each other. Neither beam has the energy to initiate the polymerization, but where the two beams do intersect, there is enough. Viola! You can now polymerize the material at exactly whatever internal volume you want (subject to diffraction limits and a whole bunch of other experimental details that I won't get into) and nowhere else. This polymerization continue until all the appropriate sites have been solidified, after which the unreacted monomers are removed. It's then time to enjoy your beautiful creation.

But be really, really careful about losing it, o.k? No sneezing, coughing or "[ing] the mirror to better see the artistry." Better yet, make it a bas relief sculpture with a large base so that you can't lose it.

Previous Years

November 18, 2013 - 73 Quarters of Losses - And Still in Business

November 18, 2011 - An All Plastic Road Bridge

November 18, 2011 - Marine Pollution

November 18, 2010 - Why the Cox-Merz Rule?

November 18, 2009 - Perfect Fluidity

November 18, 2008 - Natta's still waging a patent war

Monday, November 17, 2014

Unemployed and looking for a job

Short and sweet: I am looking for employment. My previous employer, an unnamed Minnesota-based mining and manufacturing company gave me a severance package (pretty small compared to what I got 13 years ago when I was also let go from them, but times change). And so I am looking for a job in the Twin Cities area, particularly on the east side and into western-most Wisconsin. Advice and leads are nice, but names of hiring managers are solid gold.

I also am available as an expert witness. I was one 5 times in a previous employment situation, and also twice this past year as a side gig. I enjoy the work and have been able to make significant contributions to whichever side I'm assisting.

I would also be available for consulting, but that is one tough row to hoe, and I don't plan to actively pursue it into retirement. Not only do you have to hustle hard to get into a place, but once you do, there is the animosity towards you from the technical people who really feel challenged by your presence. I saw this many times while working at Aspen Research. We weren't consultants, just contracted technical personnel (who actually did lab work instead of just talking about doing lab work) but there was still more than one occasion where it felt like Mr. Freeze and the Freezies were at the table when we sat down to talk with them about a problem they couldn't solve.

As noted above, I've been in the situation before. There are some projects that I've wanted to take on but haven't had the time, and there is that extra weight around my middle that I will be able to whack away at making me, my wife and my doctor happy (that's a nice trifecta). I have learned to make the most of this forced time off and so the usual steps of "denial, bargaining, depression, acceptance..." just aren't there. I know there will come the day when I start employment again. If I knew what that exact day was, I would really sit back and enjoy everything until that day arrived, as would anyone in such a situation. So why should not knowing the day change that outlook?

Wish me luck and yes, I will keep blogging.

Previous Years

November 17, 2011 - A boat that is completely solar powered

November 17, 2010 - ANTEC Craziness

November 17, 2008 - Logical Conclusions

Friday, November 14, 2014

Is Dow Chemical going to have a proxy fight?

Every time I keep thinking that Dow Chemical may have finally been able to tell activist investor Daniel Loeb to take a hike, he keeps coming back. What a glutton for punishment.

Loeb's latest effort is this flashy website which makes yet another logically inconsistent attempt to acheive changes that he desires at Dow. This website is designed to inform stockholders of his opinions and push for a proxy fight to get two of his handpicked directors on the board.

I'm guessing that Loeb hopes that the impressive visuals of the website will hide the desperateness of his throw-everything-I-can-think-of-and-hope-something-sticks approach. He's using performance issues from as far back as 2006 to justify his proposal. Such an approach always generates internal inconsistencies, such as his insistence that Dow is a petrochemical company [1], and yet when comparing performance to other companies lists not a single petrochemical company [2]. Strange, isn't it? I could go on list lots of other inconsistencies, but what's the point? He's looking to fool naive investors and nothing more.

I've pointed out in the past that Loeb has forgotten his calculus (shame on him, as his degree was in economics), but it also looks like he could use a little help with his organic chemistry:
This image is also from the bottom of the "Facts" tab. It seems like a mashup of molecules, so I won't fault him for the images overlapping poorly, but it does have some fragments that are begging for a keto-enol rearrangement. At least the webpage lacks those slow-motion videos of Liveris that make him look stupid/arrogant/insensitive such as we see in our political ads.

It's not as if I am a big fan of Dow. I've lodged lots of complaints against Dow Chemical on this blog, but I really dislike the approach that Loeb is taking. He's looking to cash in on a short-term investment and then leave to cause trouble elsewhere. The chemical industry has enough problems without having to worry about this type of "activism". Fortunately, proxy fights seldom succeed unless a company is really in trouble. Dow isn't, as the most recent results show, so I expect this to (once again) change nothing.

[1] As seen at the bottom of the "Facts" tab.

[2] As seen on the "Underperformance" tab

Previous Years

November 14, 2011 - An Extreme Connection between Fracking and America's Cup

Tuesday, November 11, 2014

ε-Polypropylene - "And now I've lost it."

Crystalline polypropylene (PP) has always been one of the more interesting polymers because it is polymorphic - there are multiple crystalline phases that can form. Without any special processing, the α- phase dominates. This is the one that melts at about 170 oC or so. In the past few decades, nucleating agents for the β-phase have become commercialized. I've not worked with any β-PP, but it according to literature reports, it melts at about 150 oC or so. If the crystals are drawn during processing, they will revert to the α-phase, so you need to be careful about that. I'm not aware of any commercial applications, but there is probably something out there. There is also the the γ-phase, of which even less is known.

Those three phases have been known for about 20 years and are at least mentioned in passing on most books on PP. So imagine my surprise last week to find that they have now discovered the ε-phase! Wait - I didn't even know about the δ-phase Did I miss something?

Apparently I did. Or maybe not. I'll let you decide. A frantic Google search for the delta phase turned up nothing, but one of the introductory paragraphs of the ε-phase article mentions that the δ-phase occurs for copolymers of propylene and hexene or pentene when the comonomer content is great than about 10%. So is that really a polypropylene crystalline phase? Before you decide, consider what we know about the ε-phase.

Just like with the δ-phase, the ε-phase doesn't occur with stereotactic, defect-free polypropylene, but requires specially prepared material, where "...the polymers produced have progressively lower melting transition temperature, lower homosteric pentad sequence population, and higher solubility in low-boiling solvents, indicating frequent stereochemical inversion in monomer enchainment." In other words, this polypropylene has some significant "issues". ("Normal" polyproplyene has a high melting temperature as noted above, high pentad regularity, and is insoluble in low-boiling solvents.) Somehow the defects are not enough to make this completely amorphous. So again I ask, is this really a polypropylene crystalline phase?

My opinion (which comes with a full-money-back guarantee if not completely satisfied): No, the δ- and ε-phases are not part of the polypropylene polymoprhs. For "normal" polypropylene, you can make the α-, β-, and γ-phases from the same starting material, but you can't make the δ- and ε-phases and so they are not part of the set.

Before I finish, consider this example of life imitating art:
"Unfortunately, both the details of the material and the material itself were lost when our laboratory moved to its new location."
Que up the theme from "The Medicine Man". I can only imagine the scene within the new lab: " I've lost it. Haven't you ever lost anything doctor Bronx? Your purse? Your car keys? Well, it's rather like that: Now you have it and now you don't." That would be pretty painful to discover and hats of to the researchers for being upfront about it.

Previous Years

November 11, 2011 - Birefringence in Polycarbonate

November 11, 2011 - Flashing Labels

November 11, 2010 - Olefin Metathesis

Monday, November 10, 2014

As silly of a silicone product as you will ever find

Courtesy of Chemjobber, comes this silly idea: the Silibagz - a silicone bag that is pretty hard to take seriously.

It's not as if silicone bakeware doesn't already exist. It does. So this is merely a bag instead of a muffin pan. And in fact, you can already buy silicone bags (which makes me wonder about the people behind this fundraiser and their supporters). What makes this funding effort silly are so many of the claims.

Such as
"We use platinum silicone exclusively, as we believe the only reasonable solution is a highly durable, safe and eco conscious solution [sic] (platinum silicone is the highest grade silicone available)."
That's a whole lot of misstatements in a short span. First, there is no such thing as "platinum silicone" and it is not the highest grade available. This whole "platinum silicone" concept makes it seem like it's a Platinum Album or a Platinum Visa Card. It's not. It's actually a "platinum-cured silicone" which has platinum as a catalyst and it typically used in 2-part silicones. But now let's look at the whole "eco conscious solution [sic]" statement. First you have silicone polymer, made from silica. But you can't just dump silica sand into a reactor and voila! out jumps silicone polymer. Instead, the silica is first reacted with an organic chloride over a copper catalyst to make dimethyldichlorosilane. Then you throw in some water to create hydrochloric acid and some low molecular weight oligomers that can be separated and polymerized. So just in terms of raw materials, you already have the silica, the (toxic) organic chloride, and the copper and platinum metals which need to be mined (oh, there's an environmentally clean operation that is sustainable).

But just the energy required to pull this off is also considerable. Distillation columns everywhere. "Outside of the petroleum industry, Dow Corning Corporation maintains the largest distillation operation in the world! " So how is this an "eco conscious solution[sic]"? Running that many distillation columns takes a whole lot of energy derived from the combustion of petroleum fuels (or maybe even coal!). Those energy costs are a huge contribution to silicone polymers costing so much compared to organic polymers even though the starting material is so much cheaper.

No, this whole effort is just plain stilly, start to finish. I don't think that the project initiators are proceeding in bad faith, but only that they have deceived themselves.

Previous Years

November 10, 2011 - Give me a photon! No, you better make it 2!

November 10, 2010 - Flow-Induced Crystallization #4

Tuesday, November 04, 2014

How many polymers are there?

It was suggested in another social media site this last weekend that the big chemical companies have tucked away in their vaults the results of polymerizing "...every molecule with a double bond has been treated with a free radical initiator, and every difunctional molecule has been tested as well." To which I say hogwash.

Let me give a hint as to the magnitude of the polymer world. Let's start with something simple like making a polyurethane. This is a "simple" case because the stoichiometry is pretty limited. You usually try to have an equivalent amount of isocyanate groups and hydroxyl groups (or something close to 1:1). We'll get into crazy stoichiometry in a minute. And for no particular reason other than the breadth of their offerings, let's look at all the isocyanates offered by Bayer and all the polyols offered by Perstorp. (There are lots of other suppliers of isocyanates and polyols - I'm making no particular endorsement here of any kind.) If my counting is correct, Bayer has 135 commercial isocyanate offerings and Perstorp has 34 commercial caprolactone based polyols. Just pairing each isocyanate with each polyol would results in 135 x 34 = 4,590 polymers. To further complicate matters however, sometimes 2 isocyanates are used, as are 2 polyols. So now you can have 135 x 134 x 34 = 615,060 OR 135 x 34 x 33 = 151,470 or even 135 x 134 x 34 x 33 = 20,296,980. All told that is 4590 + 615060 + 151470 + 20296980 = 21,068,100 polymers using the materials from just these 2 companies.

Now let's go for the really big numbers. Consider alkyl (meth)acrylates, a nice subsection of unsaturated compounds but by no means all the options available. Alkyl (meth)acrylates are available between methyl (C1) and at least dodecyl (C12), and the acids are nice to have as a weapon too. So that is 26 monomers available. My personal experience is that I've seen as many as 6 (meth)acrylate monomers used. That means there are 26 homopolymers, 26 x 25 = 650 copolymers, 26 x 25 x 24 = 15,600 terpolymers, 26 x 25 x 24 x 23 = 358,800 tetrapolymers, 26 x 25 x 24 x 23 x 22 = 7,893,600 pentapolymers and 26 x 25 x 24 x 23 x 22 x 21 = 165,765,600 hexapolymers potentially available for just alkyl (metha)acrylates. All told, that is 174,034276 alkyl (meth)acrylates.

But that number would rapidly be dwarfed if we included any of the common options available when polymerizing acrylates, such as
  • their ability to be used in pretty much any ratio (I've seen cases where changing one monomer by as little as 2 percentage points make a big difference in the final properties)
  • the concentration of the initiator (which alters molecular weight)
  • chain transfer agents (which also alter molecular weight)
  • reaction conditions (bulk, UV-initiated, thermal-initiated, solution, emulsion) all which have tremendous influence on the final product

Over 174 million polymers! If you had a machine setting up 1 reaction a second 24/7/365, that is still 5 1/2 years or solid work. And setting up the reaction is the easy part. You would still need to initiate the polymerization and (potentially) keep it going. And you still wouldn't be even close to the end of what polymers are available.

So how many polymers are there? I have no idea, but it is a tremendous number. It reminds me of the old joke of a young person looking at a starlit sky and asking an older person how many stars are out there. The answer: "All of them".

Previous Years

November 4, 2013 - Who's Been Eating My Ocean Plastic?

November 4, 2010 - Plastics in the "Economist"

Thursday, October 30, 2014

"No one uses IR anymore" !?!

Fellow blogger Derek Lowe normally writes a pretty good post, but on more than one occasion - especially when it is something related to polymers - he falls short. Today he wrote:"...even good old IR, which no one uses much any more..." It's not the first time he has bashed IR. Consider "Fellow chemists, raise your hands: Who's taken an IR spectrum in the last six months?" or "I know, for example, that hardly anyone takes IR spectra any more." or "It still does some things very well...but as far as I can tell, no one cares"

While I understand that this may be true for small molecule organic chemistry (Derek's playbox), for polymers, IR is the first go-to technique for solving the "what this polymer?" question. Slap the sample in there and take the spectrum. In less than 10 minutes, you have your answer. No solvents needed (or desired). At my last employment situation, we had multiple IR instruments (with multiple libraries) and they were in constant use. Other analytical labs are similar. Just yesterday in fact, the Polymer Solutions Blog discussed the use of IR for their customers.

Sorry Derek, IR is used far more than you realize, especially for analyzing polymers.

Previous Years

October 30, 2013 - Making Plastic a Verb

Wednesday, October 29, 2014

Comparing Burger Chains and Oil Companies

According to, the top burger chains in the US are
  1. McDonalds
  2. Burger King
  3. Wendy's
  4. Sonic
  5. Jack in the Box
  6. Dairy Queen
  7. Hardee's
  8. Carls Jr.
  9. Whataburger
  10. Steak and Shake
  11. Five Guys
  12. Culver's
  13. Checkers/Rally's
  14. White Castle
  15. In-and-Out
  16. Krystal

I haven't eaten at all these chains as some of them are limited to certain portions of the country. But Krystal? I've never even heard of them.

According to, the largest oil and gas companies in the world by reserves are
  1. Saudi Aramco
  2. National Iranian Oil Company
  3. Qatar General Petroleum Corporation
  4. Iraq National Oil Company
  5. Petroleos de Venezuela
  6. Abu Dhabi National Oil Company
  7. Kuwait National Petroleum Company
  8. Nigerian National Petroleum Company
  9. National Oil Company of Libya
  10. Sonatrach (Algeria)
  11. Gazprom
  12. Rosneft
  13. Petrochina
  14. Petronas
  15. Lukoil
  16. Egyptian General Petroleum
  17. ExxonMobil
So the next time you are tempted to think of ExxonMobil as this HUGE company that has incredible influence and is leading us down an irreversible the path of petroleum dependency, climate change and pollution, and away from renewable energy and a green, sustainable future, think again. They are the equivalent to a burger chain that is smaller than Krystal. If the Krystal chain disappeared tomorrow, I wouldn't notice at all. If ExxonMobil disappeared tomorrow, would it really change anything? Nope.

Previous Years

October 29, 2013 - A New Chemistry Lab Building, But Without New Chemistry Jobs

October 29, 2012 - More Open Access articles in Polymers and Rheology

October 29, 2010 - Garbage Patch Vacuum Cleaners

October 29, 2010 - Good Advice

October 29, 2010 - UV Scale-up

Thursday, October 23, 2014

Who put the "plastic" in plastic surgery?

"Plastic Surgery" is the hot topic of the day (especially as it relates to Renee Zellweger) and so the question arises as to what plastic is used in plastic surgery.

The word "plastic" is an old word that is used in many diverse settings. In materials science, there is plastic deformation. You also have the macromolecules that are the subject of most of the posts on this blog and you have the surgery. It may be surprising, but these uses are all based on the same meaning that the word "plastic" originally meant. "Plastic" comes from the Greek plastikos, meaning moldable.

The use of the word in the area of material science is the oldest application of the word and it refers to an irreversible deformation of a material. All materials can be stretched or bent to some degree so that when the applied force is removed, the material bounces back to its original shape. This is referred to as elastic deformation. But when too much force is applied, the material is permanently deformed - it has undergone plastic deformation. Whether it is a blacksmith pounding out iron, the steel for a car door being stamped or the drunk guy squishing his aluminum beer cans, its all plastic deformation. The material is being molded into a new shape.

With the development of polymers in the 20th century, macromolecules quickly became associated with the term plastic because they are quite moldable. Compared to metals which usually required large amounts of heat and force to mold them, polymers required comparatively little heat and force. The association is so strong that the word "plastic" to most people refers to polymers and little else.

Hence the misunderstanding of the term plastic surgery. The term was originally based on the idea of molding parts of the body through any of a number of techniques, most of which do not involve polymers. But because the word plastic has become equivalent to polymeric materials, you can have Joan Rivers joking about having her dead body donated to Tupperware. In fact, the etymology site noted above states that the term plastic surgery was first used in 1839, well before polymeric materials were described as plastic.

So who put the plastic in plastic surgery? We all did. But keep in mind what the word plastic really refers to: moldability.

Previous Years

October 23, 2013 - Dog and Pony Show

October 23, 2009 - Polymeric Auto Glass

October 23, 2006 - Polymers in the Proceedings

Wednesday, October 22, 2014

Dow Chemical's Earnings Keep Improving

Dow Chemical has announced their 3rd quarter earnings and as passed along by the Urethane Blog, they are up nicely.
"EBITDA(3) grew to $2.3 billion, up 24 percent versus the prior year, driven by ongoing productivity actions and improved market fundamentals. Performance Plastics achieved record quarterly adjusted EBITDA results (up 31 percent versus the year-ago period). Performance Materials EBITDA grew 61 percent with increases in most businesses, notably in Polyurethanes and PO/PG. Electronic and Functional Materials also delivered record quarterly EBITDA (up 11 percent)"
Normally I don't comment much on earnings reports, but this year has been different ever since the activist investor Daniel Loeb took up a stake in the company back in January. Unfortunately for Loeb, the company has been doing very well since then, providing plenty of egg for him to wipe off his face, such as that great earnings report that came out just 6 days after his initial critical comments. But might be expected for someone who has forgotten their calculus lessons.

Somehow I don't think Loeb will be commenting anytime soon (other than to announce that he threw his arm out trying to pat himself on the back for the great job he did in improving Dow's performance since January).

Previous Years

October 22, 2013 - October 22, 2013 -

October 22, 2012 - White Isn't Always White

October 22, 2010 - Thoughts on Losing Electricity

October 22, 2010 - Plastics - They Have a Future, but no Futures

October 22, 2010 - It's Not Easy Being Green

Monday, October 20, 2014

Martin Sheen and His Hypocritical Hate of Plastics

Last Friday I wrote of Lindsay Lohan's love of plastics. Her feelings are not shared by all of Hollywood however. Martin Sheen is a good example. On Saturday, he had a new boat christened after him. The boat is a research vessel for studying ocean plastics. While I've written many times that plastics have no business being in the ocean (or polluting any other part of the natural environment for that matter), the importance of ocean to plastics to mankind's survival to debate. Sheen says
"The biggest risk and danger to the world today are plastics in our oceans."
The biggest danger? Bigger than nuclear proliferation? Climate change? Chemical weapons in the hands of terrorist? Starvation? Disease? Poverty? These are all less of a danger than plastics?

Psst. Martin, take a look at the pictures of the new boat you're standing on.
Martin Sheen - I hate plastics. But the ones on my boat don't count, right?
You know what I see? Plastics. Lots and lots of plastics everywhere on that new boat. The blue and white paint on the side - plastics. The unpainted wood - coated with plastic. The ropes going every which way - plastics. The sails - plastics. The microphone that you are speaking into? Wires that are coated with plastic insulation (as are many of the wires carrying the electricity from the powerplant to the microphone.) The ink that was used to print your speech? Plastics are in that. The paper that your speech was written on? Plastics are in that too.

Looks to me Martin like your boat is only adding to the problem, not solving it. You better drydock it ASAP and help save the world.

Previous Years

October 20, 2011 - Who Invented Kraton?

October 20, 2011 - The Inventors of Kraton...

October 20, 2009 - Patent Quality and Value

Friday, October 17, 2014

Linday Lohan and plastic bags

I last wrote about Lindsay Lohan in April of 2013. Since that time, she has kept a pretty low profile as far as the plastics industry is concerned. But that all changed this morning when the Daily Mail published photos of her and a plastic bag:
Lindsay Lohan being a plastic bag
That's her behind the bag, leaving for home(?) after performing onstage in London last night. (The article has more photographs that show that it is indeed Lindsay.)

She can get away with this in London, but pulling the plastic bag stunt in California is going to become pretty difficult. The state just past a law banning plastic bags. So what are all the actors and actresses going to do? Hide behind a paper bag? That would make them to butt of way too many coyote jokes. Maybe Hollywood will need to change their stance and call for a repeal of the ban. Their privacy needs to be respected.

Previous Years

October 17, 2013 - Is This Really Self-Healing?

October 17, 2012 - Overlooking the Obvious: Self-Healing PVOH Hydrogels

October 17, 2011 - How to (NOT!) Determine PVC Rheology

October 17, 2006 - Off and Running

Wednesday, October 15, 2014

Polyethylene Production coming to North Dakota

While my homestate of Minnesota remains a frack-free zone (due to Mother Nature's choice to stock us with iron, copper and other minerals rather than even a drop of petroleum), our neighboring state of North Dakota is pretty much ground zero for the effort. And we hear about it a lot since many people have taken the day's drive out there for the good paying jobs. Western North Dakota is not highly populated, so manpower is short. If you can pass a drug test and supply your own housing, you can get a job. (And many hiring managers will say under their breath that they might let one of those conditions slide). Minnesota is also affected by the transportation of the flammable, petroleum liquids along the rail lines in our state. And the sudden increase in demand for the trains causes other logistic nightmares for anyone shipping anything else by rail.

Now comes a report from Plastemart that North Dakota will soon have their own world class polyethylene production facility - a $4 billion dollar investment. $1.5 million metric tonnes a year of HDPE - from North Dakota. That is pretty impressive.

In my mind, it was just a matter of time before this happened, although I've not heard anything previous about it unlike the plant being built in West Virginia to take advantage of the Marcellus shale production. At the same time, I bet that this plant will be far more expensive than the original estimate for many of the reasons I already discussed. The labor to build the plant will need to be imported - there aren't too many pipefitters out there and they are already kept busy with the existing fracking operations. And the housing shortage will only increase. While transporting polyethylene by train is much less risky than transporting petroleum liquids, it is not as efficient. The bulk density of polyethylene is about 0.5 g/cm3, a good fraction less than any hydrocarbon liquids. So that means more strain on the train network.

Looking at the very-long-term picture, at some point fracking production will dry up, and so the question be what happens to the facility. Will it be abandoned or will it continue to operate, albeit with a biobased source of ethylene, such as that produced by dehydration of ethanol? North Dakota isn't a very large corn producer, but over the coming decades, alternative biofeedstocks for ethanol will be developed, including some that could be raised in the dry regions of North Dakota. Either way, I'm prety sure that I will not see that future. It's too many decades down the road. (Yes, fracking will go on that long.)

Previous Years

October 15, 2013 - Turning Plastic Bags into Carbon Nanotubes

Tuesday, October 14, 2014

Yet more activist investors thinking they can run a chemical business

I've been writing a fair amount this past year about Daniel Loeb and his efforts as an activist investor to tell Dow Chemical's CEO how to run his business (1, 2, 3, and 4).

Since Dow is doing so well (no doubt as a direct result of Loeb's guidance (/sarcasm_off), Loeb is looking for a new place to produce similar results, now setting his sights oversee on DSM. He wants DSM to sell off the low profit plastics business and focus exclusively on the baby food and nutrition supplements business which operates at much higher margins. In other words, he want to be able to cherry pick and be appreciated as a business genius for doing so. While it might be easier to divide up the DSM pie than the Dow Chemical pie (i.e., there is less overlap between different operating units within the company), to say that this will "create value" is something I don't see. (A + B) = A + B. This is a really simplistic example of the associative property, but we've seen in the past the Loeb isn't very good at math.

And lest you think that Loeb is the only one being a pain in the posterior for the chemical industry, think again. C & E News reported a few weeks ago that Dupont has their own activist investor complaining to management. Such are the times we live in. If you have a stack of cash, you can get Wall Street to listen to you even if you are full of skatole-type compounds.

Previous Years


Monday, October 13, 2014

Dinosaur Mode

I had some very strange dreams towards morning including this gem: a cellphone that would mock me. Every time I would try and do something with it such as texting, a picture of an apatosaurus-type dinosaur would appear on the screen, implying that I was using an old, outdated technique and that faster, more efficient options now existed. That's not fair! I can't text as fast as my son (whose replies seem to violate the space-time continuum), but I'm more than able to find an efficient option for most tasks.

If any cellphone manufacturers want to use this idea, go ahead. It's yours for free.

(That's all for today - I'm booked solid. I'll get back to polymers tomorrow.)

Previous Years

October 13, 2010 - Calling Mr. Murphy...

October 13, 2010 - Pushing the Laws of Science and Man

October 13, 2010 - Never Mind

October 13, 2009 - Diodes, Diodes Everywhere

October 13, 2008 - Another Unusual Water Soluble LCST System

Thursday, October 09, 2014

An Ironic Effort from Greenpeace

Here's today's newest example of irony:Greenpeace succeeded in pressuring Lego into cancelling a toy give away with Shell. (Fill up with at least 30 liters and get a free Lego toy). Greenpeace was going after Shell because of Shell's efforts to extract oil from Arctic regions, but the irony is that Lego toys are all made from petroleum-based plastic (ABS). So does this change anything? Anything?

Previous Years

October 9, 2013 - Preventing Oxygen Inhibition during Polymerizations

October 9, 2012 - Some Open Access Articles from Wiley

Wednesday, October 08, 2014

"Let's Get Rid of the Mole"

Being called one-dimensional is usually not a good thing. But a recent letter to the editor published in C & E News (hat tip to Chemjobber) is proposing that we all take one step closer to that state by getting rid of the mole, the counting unit used in chemistry. The proposed alternative is we use the yotta (= 1024) instead since it is pretty close to Avogadro's number (6.022 x 1023). And after all, learning about the mole is so difficult for high school students and we should all adopt to their needs.

To show the silliness of the proposed idea, let's consider getting rid of all our basic units of measure and just go with one. Length. The meter, the yard, the light-year, it doesn't really matter. Everything can be measured with our 1-unit system and school kids will thank us forever.

Let me show you how to do it. For our given unit length - call it the Spevy, denoted by [1]. Light in a vacuum will span that distance in a certain time interval t. t = /c. If you take c as dimensionless, t is now measured in length as well. And now we are off to the races. Literally. Velocity is next. That is a length over time, both of which have identical units and so velocity is dimensionless. Similarly, acceleration would have units of inverse length.

The gravitational force between 2 masses is proportional to the mass and inversely proportional to their separation, so that is the yet-to-be defined mass squared over length square, F = M2/L2. This is also equal to mass times acceleration F = M a. Set these two equal and solve for M: M = a L2. Since acceleration has inverse length, mass has a unit of length.

No more moles kids! It's all Spevy's from here on out. What's a Spevy? It's something about that long. Doesn't that make chemistry so much easier? It's all just distance. No more worrying about counting the yotta-number of atoms sitting around in a flask, just pull out a Spevy-stick and go at it.

Equally extreme would be to make every measurement as a basis unit with no relationship between any one measurement and the other. It would be the Humpty Dumpty approach where the units means just what I choose them to mean — neither more nor less. [2]

The best approach is to find a middle ground, somewhere between 1 and infinity. The SI system is at 7. But even at that, there are thousands of other units that people still use because they are convenient. Astronomers use light-years not to cause confusion, but to reduce it by keeping the numbers manageable, just as particle colliders measure areas in barns (and millibarns and...). And other units are valuable because they can be more clearly understood. Take gasoline mileage. In the US, we use miles per gallon, but this can easily be reduced to an inverse area. Miles are a length, and gallons are a volume, a length cubed. Divide a length by a length cubed and you end up with an inverse length squared = inverse area. Elsewhere in the world, liters per 100 kilometers is used for mileage, so that can be reduced to an area. But in either case, is any information more clearly communicated than using the non-standard units?

As the letter-writer states, the mole arose during a previous time when our knowledge of atoms was so much less, but that doesn't mean that the unit should be discarded anymore than we should discard other units developed in earlier times, such as the second, minute and hour (all of which were based on the presumption that astronomical motion was so much more precise than it actually is, hence the need for leap years and leap-seconds.)

I'm not worried that anyone is going to stop using the mole at any point now or in the future. We have too much existing literature that would be unintelligible if that change could suddenly occur. And while I very strongly emphasize for the difficulty of learning high school chemistry [3], there are far more challenging ideas to be learned as the education continues. If someone decided not to pursue a chemistry career because they didn't understand the mole, they were not going to have a successful career in chemistry regardless of whether the idea was taught or not. Quantum mechanics, despite it's probabilistic nature, would guarantee the end.

[1] That's a backwards 'S' to further emphasize how backwards this whole idea is. The HTML code is & #4343 ; if anyone wants to pick up on the idea and run with it.

[2] When you look at the yields of some published reactions, you sometimes get the feeling that that reality is closer than we think.

[3] I know this from personal experience. I had a truly horrible high school teacher that left me ill-prepared for college chemistry. By the second week of freshman chem, I was already in trouble. But I put in the extra time and succeeded.

Previous Years

October 8, 2013 - 3 Small Bites

October 8, 2012 - A World-Wide Diaper Shortage? Yeah, but that's just for Starters

October 8, 2010 - What is Resin and What is Plastic?

Tuesday, October 07, 2014

A New Plastics-to-Oil Operation - In Syria?

I written in the past 1, 2 about "Plastics-to-Oil" (PTO), the process for anaerobic pyrolysis of plastics which ends up creating a sweet, crude oil. There are a few smallish operations here in the US but at this point in time, it does not play a critical role in our economy. And with gas prices continuing to fall (I saw $2.99/gallon yesterday for the first time in about 5 years!), that won't change soon.

But is Syria, the story is different. There, all fuels are at a premium and so PTO suddenly becomes a life changer. One crude operation is run by Abu Talal:
"'We get plastic materials from areas and buildings that are deserted after being shelled by the regime forces. We collect all the plastic we find, such as water tanks and drainage pipes.' After Talal and his team gather the plastic, they cut it into smaller pieces and put 50 kilograms in each barrel, along with 20 meters of piping to cool the water that runs in and out of the barrel. They contain narrower tubes, which contain the fumes that come from the burned plastic. Then they light a fire. 'It takes two to three hours to extract as much as possible from one batch of plastic,' he says. 'In the last stage, we get the temperature to 100 to 115 degrees to extract a kind of diesel. The temperature must be accurate for the diesel to come out and for it to burn well, so it can be used in cars and motorcycles.' "
This is not exactly how PTO is run on a larger scale. Rather than inserting an inert gas, the air in their reactor must be displaced over time as the plastic starts to degrade, forming near-anaerobic conditions. Also, PTO is typically run at much higher temperatures (800 oF or so), but regardless of these details, the system still works well enough. And it serves as a reminder of how creative people can become during desperate times.

Previous Years

October 7, 2013 - 1000 Posts

October 7, 2010 - The Strange History of Bubble Wrap

Friday, October 03, 2014

Carcinogens I've Worked With

The Department of Health and Human Services issued the 13th edition of their Report on Carcinogens this week. The list is not just chemicals, but includes physical hazards such as gamma radiation, and biological agents (hepatitis B and C for instance). I decided to take a look at the list and see what I've exposed myself to over the years.

The list is actually split into two categories - those known to be human carcinogens and those reasonably anticipated to be human carcinogens. The former is a rather short list and I haven't worked with many items on it. Some UV lights, some X-rays, some wood dust, but that's about it.

The anticipated carcinogen list is much more exciting to read. Acrylamide, acrylonitrile, phenolphthalein, styrene and toluene diisocyanate. (Note that the list includes "urethane", but they clearly indicate that this is only referring to ethyl carbamate and not the polyurethanes that make up so much of my current chemical life). Thinking back on my school days, I would have to add carbon tetrachloride, naphthalene, and o-nitrotoluene. So 243 substances and I've worked with 11 or them - 4.5% pretty clean living I guess. However, that number is sure to rise over the coming years as more studies are completed.

I can't close however, without mentioning one item on the list that I've never worked with. That chemical grabbed my sense of irony and shook it hard - cisplatin. A drug used to fight cancer likely causes cancer. It does make you wonder...

Previous Years

October3, 2013 - Propylene in Space

October 3, 2012 - 3D Printing a Gun

October 3, 2011 - Rheology Analogies for Computer Networks

Thursday, October 02, 2014

Rubber Gloves and Ebola

The Atlantic has a an article today about subject that I first wrote about back in August – that polymers, and rubber gloves in particular, play a critical role in the fight against Ebola.

The virus itself is thankfully not all that contagious. It is not spread via the air, but rather by direct contact with bodily fluids. A simple rubber glove, just a couple of mils thick, is more than enough protection, and yet sadly, the article notes that such a simple item is missing in many health care situations in West Africa.

"Malaysia, the world's leading manufacturer of rubber gloves, sent 20 million pairs last month to the five affected countries. Direct Relief said that between Malaysia's gloves and the organization's own donation of 2.8 million pairs, there will be enough gloves to last for 130 to 260 more days. But that doesn't account for 'correct glove sizes, breakage, distribution considerations, or exponential growth of the disease. Nor does it include burial teams, disinfection teams, ambulance transport teams, and investigation teams. It also doesn’t consider the preexisting need.' "

This outbreak of the disease will be ended in the same manner as previous outbreaks – via public health measures, not through vaccines. Rubbers, plastics and other polymeric materials will be a large part of those measures. (And most of it will be that dreaded “single-use plastic”, I might add.)

Previous Years

October 2, 2013 - Responding to Crackpots

Tuesday, September 30, 2014

A Mixing Demonstration using non-Newtonian Blue Maize Flour Suspension

The Journal of Chemical Education has an article on mixing in non-Newtonain suspsensions that is visually appealing. They use blue maize flour, a material whose color is pH sensitive (I didn't know that). It goes through the color sequence shown below.
Blue Maize Flour at different pH values
Being a flour suspension, the material is non-Newtonian with a viscosity that changes with shear rate. But even more intriguing is that the viscosity of flour/water suspensions is pH sensitive. So as you might expect, the demonstration/experiment is to observe how well a liquid of different pH gets mixed into the suspension over time. Or doesn't, in this case. Taking 13 minutes to incompletely mix ~ 1.5 liters is not time effective in my world.

The authors are appropriately emphatic about the differences in mixing between laminar and turbulent settings (a distinction that any chemical engineering student understands, but few chemists do). Without getting into defining the Reynolds number and other engineering concepts, I'll keep it simple and say that with low viscosity fluids and high mixing speeds, you have turbulent flow and effective mixing. Conversely, with high viscosity fluids and low speeds, you have laminar flow and poor mixing [1]. In turbulent flow, mixing is as easy as falling off a chair, but in laminar flow situations, effective mixing is only achieved with chaotic mechanisms [2].

Mixing blades
The disappoint part of the paper is that the mixing blade is never shown and there is no discussion about how different mixing blades could alter the outcome. Given the wide variety of mixing blades available, this would be easy to pull off and would help students learn that picking the correct mixing blade is almost more art than science. And then there is blade diameter as well, and side sweep arms and...

Nonetheless, this is a good demonstration, one that I would have found helpful back when I was first learning of these issues. As more and more of our materials are produced from multiphase suspensions and emulsions, this knowledge will become that much more important.

[1] From Mixing in Polymer Processing ed, C. Rauwendaal, 1991, p. 2 "A polymer flow would have to be the size of the Mississippi River and moving at hundreds of miles per hour to have [turbulent flow]."

[2] The chaotic mechanism that most people are familiar with is kneading bread. You have a very high viscosity material and (besides building up the gluten network) you want to mix the ingredients very thoroughly. So you stretch and fold and turn, and stretch and fold and turn, and...

Previous Years

September 30, 2011 - Now that we have the "Perfect Plastic", you don't need me

September 30, 2011 - The Research behind "The Perfect Polymer"

September 30, 2010 - Pyridine

Monday, September 29, 2014

Ocean Plastic - The Truth and More Hype

I ran across a couple of articles this weekend regarding ocean plastics that are worth a read. The first is from, entitled 8 Things You Should Know About Plastic in the Ocean. The amazing aspect of the article is that it gets it right. Or at least the text is correct. The pictures tell another story. They are still of macroscopic objects on beaches or in the water. But the text is correct. In brief, there is a lot of plastic particles out there, but we don't know how much, we can't collect it and the problem starts back on land.

Of course the comments go right back off the deep end (ha!) such as this one by Jeff:
"The ONLY real solution is to stop making plastic. Cleanup on a massive scale like this is pure fantasy and delusion. On top of that, there's no way to clean up the small stuff and what's been eaten by wildlife. Humans lived their entire history without plastic until recently. Plastic is unnecessary and totally harmful and should be outlawed."
Hey Jeff, no plastics? No Internet and no Facebook!

And then there is beauty about the newest brainstorm from James Dyson's (that charming Brit behind the Dyson vacuum cleaners that were claimed to "never lose suction" [1]). He's now proposing to use his one trick pony of cyclonic separation [2] to attack river plastic. While grabbing plastics from rivers before they make it into the ocean makes sense, his idea is problematic. First, it only focuses on large pieces of plastic. Second, the plastic, once recovered, is shredded and then passes into a cyclonic separate where it is magically separated. I say magically because the difference between all the grades of polyethylene (High-density, low-density and linear, low-density) is pretty small, making their separation very challenging. And then there is polyproplyene too that would mixed in as well. Yet the separation needs to be very effective or else the recovered plastic is of very low value. And Dyson knows this since that is why he wants to separate the various plastics in the first place.
"The Recyclone barge has not yet been prototyped or tested, but Dyson said he is convinced it can work."
Well that's enough to convince me. How about you?

[1] Funny how they don't make that claim anymore. Is it because it isn't true?

[2] Cyclonic separation is the answer [3]. What's the question?

[3] Multicyclonic separation is the answer. What's the question?

Previous Years

September 29, 2011 - Presenting Rheology Data

September 29, 2011 - Cool video of the day

September 29, 2010 - ANTEC is accepting papers

September 29, 2010 - More Destuction from Windows Reflecting Sunlight

Monday, September 22, 2014

Back from Vacation

I just got back from a week's vacation so this will be pretty short as the email box is quite full as so is the calendar. But it is worth it. Consider the alternative, which is what I tried this past summer - taking Friday afternoons off. What a failure. While it did avoid the overstuffed email box and calendar, what it really did was shorten the workweek, but not anyone's expectations of what I would/could/should accomplish.

So no more of that approach. This week was different. Everyone knew I was gone so no one expected me to do anything (except for the calls when there were some critical issues that really needed my input). Today will be hectic, but a week of peace and quiet was worth it. I even got to see Jens Voigt break the hour record online without feeling guilty about it.
Jen Voight - Hour Record
Jen Voight - Photo Courtesy of VeloNews

The hour record is arguably cycling's most difficult accomplishment and also it's simplest. You ride and see how far you can go in an hour. Whether or not you break it, it breaks you. It takes months of specialized preparation and then some. The effort is as much psychological as physiological, and there are months of recovery afterward just so you can look at your bike again and not want to destroy it with a 10-pound sledge. Hence, it is usually the capstone effort of a career and Jens is just such an example. He has now retired from professional bicycle racing.

Previous Years

September 22, 2011 - Another Source of Ocean Plastics - Your Clothing

September 22, 2010 - Watch out all you Grandparents!

September 22, 2009 - Self-Healing Plastics