Thursday, January 28, 2016

There's something Fishy about so much Plastic in the Oceans's future

A long time reader of the blog, Alan Blayney, first brought to my attention the "splashy polymeric headline of the day" (his words, not mine) about the report released by the World Economic Forum/Ellen MacArthur Foundation (WEF/EMF) regarding ocean plastic. It's been all over the news, usually under the headline of how by the year 2050, plastic in the ocean will outweigh the fish.

You can read a summary or the full report if you so desire, but I really would recommend against it. I found it very difficult to go any further than 2 sentences without grunting, slapping my head, rolling my eyes and otherwise expressing frustration. That this report took three years to put together is mindboggling. It really looks like a cut-and-paste job by a 7th grader. Seriously. While the vocabulary is well above a that of a 7th grader, the logic might even be below that level.

I cannot even begin to start with a detailed response, so let me give you a couple of high-level arguments which should be enough to support my previous comparison.

1) On page 14 of the full report, they have Figure 5:
WEF Estimates on the future of plastics in the oceans
Let's just focus on the oil barrels, showing that plastics consumption of oil growing from 6% to 20%.

My fist thought was Wow! Plastics are really going to explode like that? How come no one else is expecting such a boom? So then I looked into the details. The WEF/EMF relied on an IEA report for future oil production. The IEA report is actually fairly involved and looks at multiple scenarios for future oil production, including one called "New Policies Scenario", which is described as
"The New Policies Scenario – the central scenario in WEO-2015 – takes into account the policies and implementing measures affecting energy markets that had been adopted as of mid-2015 (as well as the energy-related components of climate pledges in the run-up to COP21, submitted by 1 October), together with relevant declared policy intentions, even though specific measures needed to put them into effect may not have been adopted."
There is also a "Current Policies Scenario" which is based on, you guessed it, current policies, rather than the wishful thinking of what politicians have promised. The New Policies Scenarios then assumes that less oil will be used for energy production, hence the relative increase in the percentage of oil used to make petroleum. No boom at all. It's all just slight of hand that may or may not happen.

But even if this does happen, the question remains: so what? Let's carry out the "New Policies Scenario" to an extreme and imagine that in 2050, all energy is petroleum-free (we're all driving Teslas and heating our homes with bio-methane, etc..), in which case plastics will consume about 50% of all the petroleum extracted (the other 50% going into non-polymeric chemicals as currently happens). Why is that a bad outcome? Or even if plastics consumes 100% of the oil produced, why is that bad?

The point of this figure is to create the illusion that plastics are growing like made and the reality is that they aren't.

A further argument against this illustration is that they are playing fast and loose with future policies and changes in consumer behavior. Because it helps their cause, the WEF/EMF assumed that changes will occur within oil production (the "New Policies Scenario"), but then rather than using a "New Policies Scenario" for the future of plastics, they use a "Current Policies Scenario" for plastics use. What wonderful logic. The mind reels.

2) The report is largely focused on plastic packaging, although there are plenty of examples where the distinction is not clear at all. But let's focus on the packaging aspect. On page 12 of the full report is Figure 3:
WEF estimates on economic loss from plastic packaging
While you can argue with the 95% number, an even bigger counter argument can be made regarding this illustration. Consider again petroleum production. 100% of it ends up in a combustion reaction and would anyone consider this an economic loss? Or is this energy consumption a basis for having an thriving economy in the first place?

Like almost all generic complaints against plastic packaging, the arguments always focus on the "single-use" aspect of it. And why it is certainly true that most plastic packaging is not reused, by focusing on just the very last activity, the bigger picture is lost. Plastic packaging is required to meet a very large list of requirements for a number of customers, not just the final consumer. Consider the hated PET water bottle:
  • It needs to seal the water in and all other contaminants out. That's pretty obvious, that's on the top of everyone's list, but for some people, they think the list stops there. It doesn't.
  • It needs to be made from materials that will not leach unsafe levels of chemicals into the water, or react with the water. The FDA monitors this, but some people are still not happy with the results.
  • It needs to not have any structural failure:
    • during shipment from the bottles' manufacturer (who is often someone different than the company filling the bottle) to the filling plant
    • while it is in the filling equipment
    • while the bottle is put into
      • the secondary packaging (often shrinkwrap)
      • into the tertiary packaging (a cardboard box)
      • additional packaging (such as to secure it to a pallet)
    • or during shipment via (multiple) trucks or boats
    • while on the shelf or rack, particularly when multiple layers of filled bottles are stacked on top of it
    • during the "normal" lifespan that the consumer has it
  • It needs to withstand temperature extremes from below freezing temperatures to 140 oF or more, as well as UV light which can degrade polymers.
  • The water needs to diffuse very slowly through the bottle's walls. Once too much water has evaporated, the bottle no longer holds the volume stated on the label, say 500 ml. Now it's mislabeled, and cannot be sold, so into the wastestream it goes.
Consider the consequences of just one bottle failing these requirements and leaking. At the very least, that water is lost. But depending on the location of the bottle within a shipment, additional bottles may be lost if the cardboard becomes wet and weakens, perhaps even and entire pallet full of water bottles. That is a true loss of economic value.

I could go on (and on. And on. And on.) but you get the point. If you want a good laugh, look at the "moon-shot" (yes, they used that word) technical innovations that they propose on Page 26. I can't wait to get started working on that new "super-polymer". Who's in with me? Maybe a Kickstarter project. We'd only need $50 million or so.

Lastly, I found the following comment in the report to be as filled with irony as any I've ever read:
"Society’s perception of plastics is deteriorating and perhaps threatening the plastics industry’s licence to operate. According to Plastics Europe, an industry organization, 'There is an increasingly negative perception of plastics in relation to health, environment and other issues'."
I wonder why?

Previous Years
January 28, 2014 - Dynamic Mechanical Analyzers - Male or Female?
January 28, 2011 - Miscellany
January 28, 2011 - Designing a Crematorium
January 28, 2010 - Holy Grail Projects
January 28, 2009 - Chemical Security
January 28, 2009 - So that's what it's called...

Wednesday, January 27, 2016

Another example of the lonliness of polymer chemistry

I recently discovered the Open Syllabus Project, a site that crawls the web looking for syllabuses and then looks at what texts are being used in the class. From this, they prepared ordered lists. While the Project openly admits that their methodology is not perfect [*], it can be considered somewhat representative of what texts are being used and to what degree. Can it accurately split the difference between #11 and #12 on the list? Probably not. But they should be able to clearly differentiate between #1 and #100.

You can filter the list by different fields. When the "Chemistry" filter is applied, the #1 text is "Chemistry: The Central Science" by Brown, et al. No surprise there - it's the text I use and I've always heard that it is extremely popular. There are 3 other General Chemistry texts in the top 10, as well as 4 Organic texts, 1 P-Chem text and 1 Analytical text, which is also not too far from what I would expect. Enrollment in upper level chemistry classes is always much smaller since all the premeds and other nonmajors have left, so P-Chem, Analytical and Inorganic would be expected to be lower.

Being a polymer chemist, I'm curious where the first polymer chemistry text is on the list. It's a disappointing #122 - Polymers: Chemistry and Physics of Modern Materials by J. M. G. Cowie. In fact, there are 9 biochem texts higher on the list than this. 9! Apparently polymer chemistry classes are quite rare, about as rare as the polymerization of a non-terminal olefin. Augsburg College, where I teach, doesn't have a polymer chemistry class (despite my efforts to create and teach one), and I suspect that that is true elsewhere given the data above.

This is all just another example of how lonely it is to be a polymer chemist. If you want to be rich and/or famous for writing a chemistry textbook, write one for General, Organic, Physical, Inorganic or Bio-chemistry. ANYTHING but polymer chemistry.

[*] Of that I'm sure. The syllabus for the class I teach is only available on the college's internal website - no webcrawlers allowed.

Previous Years

January 27, 2012 - Open Access, Curation and Seredipity

January 27, 2011 - Baroplastics

Tuesday, January 26, 2016

King Tut is now minding his own beeswax

Exactly a year ago, I blogged about King Tut's iconic mask being damaged, specifically that the beard had fallen off and was hastily repaired by the 3 Stooges and some 5-minute epoxy (all of which exposed him to TOXIC! levels of BPA). A German art conservator was brought in last fall to attempt a repair.

The National Geographic website reported back in December on his efforts. These included removing the epoxy by heating it and using wooden scrapers to avoid further damage to the mask. Prior to this, they performed a number of scans on the mask and discovered that a previous repair from 1946 had been done using a soft solder. But in this repair, they used an adhesive with ancient roots - beeswax.

As you might guess, beeswax adhesive is not straight beeswax since it is just a softish waxy material with little or no adhesive properties. It is typically mixed with rosin to increase the tackiness. That this is a "natural" adhesive is a selling point, but the repair is certain to not last an eternity (too bad, as Tut will need it that long). Another repair will be needed at some point down the road, but removing the beeswax adhesive should be relatively simple compared to an epoxy.

I wonder how they decided on beeswax, and more importantly, how much (and which) rosin to add to it. Like any tackifier, too much rosin will decrease tackiness, so getting the levels just right is important. Rosins also have varying degrees of unsaturation, all of which will be oxidized over time and potentially changing the adhesive. It would be nice to think that this was all studied and analyzed in great detail, but I suspect that might not be the case.

As for the fate of the artifact-altering-associates, they are facing trial for their "work". There is no word on what potential sentences they are facing, but I think gluing their fingertips together with an epoxy or a cyanoacrylate would be a good start.

Previous Years

January 25, 2015 - King Tut and BPA

January 26, 2012 - Viewing History through an Oil Refinery

January 26, 2011 - My Most Embarrassing Moment at Work

January 26, 2010 - Phosgene Death

January 26, 2009 - More on Dow and Rohm & Haas

January 26, 2009 - Biodegradation of Polymers

Tuesday, January 19, 2016

LA to Feds: Thanks everyone! We had a ball! (or 96 million)

Back in August to much hoopla, Los Angeles placed 96 million black HDPE balls on top of their water reservoirs. Plastics News is now reporting that the balls on three of the four reservoirs are being removed due to federal regulations.

Reaction to the balls has varied from the start and not surprisingly, some people were very suspicious going so far as to establish a Reddit community rife with conspiracy theories. That some in that community believe the balls leach BPA is hardly surprising.

It's not mentioned what will happen to the used balls. A massive ball pit is always a possibility, but most ball pits that I've seen use multicolored balls and not just black ones. Recycling options are somewhat limited as black HDPE isn't all that common. (Black is common in film form, but I suspect the melt index for these molded balls is far too high for film formation.) I think the most likely outcome will be a classified ad in Plastics News:
For sale: 96 million used black HDPE balls. 4" diameter. Available for immediate pickup in Los Angeles California. Cash only (We're still flirting with backruptcy!). Special consideration will be given to businesses in the St. Louis, Missouri area (we feel really bad about taking back the Ram -- we really do. NOT!)

Previous Years

January 19, 2012 - A Bad Day in the Operating Room

January 19, 2011 - What's in a Name?

January 19, 2010 - What's In My Inbox

Monday, January 18, 2016

Molten Aluminum and Superabsorbant Polymers

I'm not sure that there is much "science" in this video, but it does use superabsorbant polymers to create some pretty neat art at the end from molten aluminum.

I hesitated to draw attention to this, but it already has over 4 million views so I'm not pointing out something that would otherwise go unnoticed. It's just that most of the demonstrations of "The Backyard Scientist" are done with poor safety precautions and as you heard in the video, a cavalier attitude towards them. The description page on YouTube states in part:
"Almost everything I do can be considered dangerous, but I have been doing this stuff my whole life. I have experienced burns, cuts, temporary hearing loss, shocks etc etc.. But with each mishap I have learned something the most important way, by experience."
Wow. Thankfully this guy videotapes everything so that, heaven forbid, when that day arrives where something does go seriously wrong, it will be well documented so that others can learn from his experiences.

Previous Years

January 18, 2012 - Criticisms of "Atom Economy"

January 18, 2011 - Plastic Debris in the Great Lakes

January 18, 2010 - From Large to Small

Thursday, January 14, 2016

The test results I've been waiting for

Over the past few years, I've been happily trashing the research of Prof. George Bittner (here's a short summary), who has this ability to create chemicals in plastics that have estogenic activity (EA) and then claims as a result that the chemicals are in the original plastic and that consumers shouldn't use them. It's not all that different from "salting a mine", but just in reverse. That he owns 2 companies that perform such testing and then supply "EA-free" additives suggests a profit motive rather than this work being strictly academic.

Not quite a year ago, I posed this question:
"For the life of me, I cannot figure out why the researchers haven't run the simplest and most appropriate test of all. Take a bottle of Tritan or whatever other glassy plastic you are trying to skewer this year, wash it out with soap and water (like a normal consumer would before their initial use), fill it up with water and let it sit for 2 weeks. Let it sit in the fridge or let it sit in a car or let it sit up on the roof of the CCi building and then look for EA in the water. Just do something with it that a normal person would do instead of acting like that's not good enough."

Yesterday, I found out that someone has actually done just this! The researchers bought 20 reusable water bottles, put water in them, let them sit for 24 hours at 40 C (104 F) and then tested the water for BPA. Guess what? They found BPA in only one brand of bottles, a polycarbonate-based bottle that did not even claim to be "BPA-free".

Shocking results, huh? Pretty hard to argue with them too. It was the simple test that I have been asking for, the one that Bittner et al. never performed (or at least, never published the results if they did run it). A critic would comment that the water really should have been tested for EA, and with that I would agree. But at least we now have someone who knows how to run the test correctly.

Previous Years

January 14, 2015 - Monkey see, monkey do

January 14, 2014 - Finally a Commercial Phosphorus Polymer?

January 14, 2010 - A Viscoelastic Surface for People, too!

January 14, 2010 - Recycling Plastics

Wednesday, January 13, 2016

The Mysteries of Ice Skating

That the physics of ice skating are still is not fully understood is not surprising. Making measurements on a small area that has dynamic pressure conditions wedged between the ice and the steel blade is extremely challenging. We know that ice is inherently not slippery, and that only because of the pressure of the blades somehow "melting" the ice or otherwise creating a liquid-like surface that skating happens at all. Long ago as an undergrad, I was taught that the pressure of the blade alone is enough to alter the melting point of the ice. This change can be calculated via the Clausius-Clapyeron equation but a quick back-of-the-envelope estimation shows that an enormous amount of pressure is needed. This was handwaved away by the instructor stating that skates are hollow ground (i.e., they are concave down as you look to the length of them) to increase the pressure.

Imagine my shock a few years later when I took up speedskating and found out those blades are flat ground. That right, the skates that are the fastest are the ones with the largest contact area. So much for Misters Clausius and Clapyeron (and my instructor).

New research offers a potential new explanation of ice skating. It's currently pay-per-view so I haven't read it (it will likely become downloadable in the near future as are most of the PI's papers, but I wonder if the article will really get at the dilemma that I mentioned above: the role of contact area.

Hollow ground skates are used for sports where turning tight corners is necessary, so have a "biting" edge is essential. In speedskating, having a friction free glide is essential to maintaining speed. But are there points where either approach becomes too extreme? Can skates with an extremely small contact area (an atomically thin edge?) have any value or would the performance degrade? And for speedskates, would a larger surface area aid or hinder performance? Is there a limit on either end?

I've puzzled on these questions over the years, but the greatest mystery to me is this: is there any value in creating a hybrid skate? One that is hollow ground on one or more portions and flat ground elsewhere. Maybe hollow on the front and back for turning on the toes or heels, but flat ground in the middle for maintaining speed. Even without understanding the physics of ice skating, I would love to see someone try such hybrids as I think it could provide in some very unusual results.

Previous Years

January 12, 1015 - Kinetics, Thermodynamics and Polymer Phase Transitions

January 13, 2014 - Still Proposing Changes to the Resin Identification Codes

January 13, 2010 - Race Horses and Rheology

January 13, 2009 - Walking Polymers

Wednesday, January 06, 2016

The IUPAC ranges for atomic masses are NOT useful

While there is considerable excitement about the 7th period of the Periodic Table being completed, I've been thinking about more mundane matters about the table.

I was recently reminded that for many of the elements on the periodic table, IUPAC has assigned ranges and not specific values to the atomic masses. I wrote about this 5 years ago and haven't done anything with it since, so I took some time over break to look into the matter further. Being an organic polymer guy, I started with carbon, since on an atomic mass fraction that element makes up the largest component of most commercial polymers. The range for this element is between 12.0096 and 12.0116 amu, which is pretty tight, about 0.017% if my math is correct. This is beyond the accuracy with which we can measure molecular weights of polymers, so even worrying about the impact on the molecular weight of ultrahigh molecular weight polyethylene (UHMWPE) is not a concern.

But I was also struck by the plot at the bottom of the IUPAC page, which is reproduced here:
Source variations in the atomic mass of carbon
This plot shows how range of atomic masses for carbons strongly depends on the source. The largest range is in marine sediments, while other sources of carbon, such as crude oil, have significantly smaller ranges. But ironically, rather than providing justification for a range, this plot completely undermines the efforts.

I completely understand the importance for knowing these variations for fields where extremely high accuracy is needed, and I would imagine that any researcher needing to know these variations would be made aware of them very early on in their research efforts. But very few if any researchers are going to be working with carbon sources that cover this vast range. Most organic chemists are going to be working with carbon supplied from crude oil and nowhere else.

So this then begs the question of whether the ranges supplied by IUPAC are of any value. If you are like most chemists, 12.011 amu, the previous standard atomic mass for carbon is likely to be adequate enough. But if it isn't, then the new range of 12.0096 - 12.0116 amu is unlikely to be of any value either. Yes, the range is large enough to cover all the various carbon sources, but is it really necessary to have a range when a single value is sufficient for most work? And for researchers that need to understand to consider a range within their samples, any of the individual ranges in the figure above would be more helpful than to use the entire range of values supplied by IUPAC which is all inclusive.

A good chemist is going to use the range of atomic masses that makes the most sense for them. The IUPAC range is not clarifying the matter, only muddying the waters.

Previous Years

January 6, 2015 - Weeding-out Engineering Students

January 6, 2014 - How Cold Is It???

January 6, 2012 - Free Access to Articles in the Polymer Literature

January 6, 2010 - Polycarbonate (and BPA and Phosgene)

Tuesday, January 05, 2016

Another overhyped polymer to start the New Year

It's been a year-and-one-half since the science press last went gaga about a new wonder polymer from IBM researchers that does everything, including making us all better looking, more intelligent and with naturally wavy hair. So we are overdue for a new such polymer.

Esteemed fellow blogger Chemjobber first made me aware of this wonder polymer back in December. I hoped that the hype would have quickly died down, but was disappointed to find that it is alive and kicking a month later.

The research report was published in Nature Chemistry (subscription required), and describes the ring-opening polymerization of γ-butyrolactone (GBL) to form a type of polyester, as well as the depolymerization of the polymer, accomplished via heating.

That the researchers were complicit in hyping this research is what I find most upsetting.
"Textbooks and scientific literature had described these small molecules as too happy and thermally stable in their monomeric chemical states to polymerize. 'Don’t even bother with this monomer,' Chen summarized the conventional wisdom. 'You cannot make a polymer out of it because the measured reaction thermodynamics told you so.'"
Wow. A textbook is wrong? How can that be? (Maybe someone should read yesterday's post about textbook mistakes.) What is more disingenuous about this is that the authors are well aware of previously reports on the polymerization of GBL, since they cited many of these reports and even the review article on the topic. So is this polymerization really that novel?

Polymerization/Depolymerization GBL
But the hype continues as the authors give us the illustration on the right. Not only can they polymerize the GBL, but with heat, they can depolymerize it too. It's a neat trick, but hardly novel. It's so well established a concept that there is a term for it: ceiling temperature, and it even has its own Wikipedia page. That's right, there are LOTS of polymers that depolymerize upon heating to reform their monomers. So why call this "hot breaking" as if it is something new? (Worse yet, why call the polymerization route "cold fusion"? Who wants to be associated with that?)

That the hype over new wonder polymers is created by people drinking the same Koolaid, look at the term the researchers use to call the thermal depolymerization: "recycling". That is the exact same word used by the researchers at IBM behind last year's wonder polymer (linked to at the beginning) who also claim that reverting their polymer back to its source monomers is "recycling".

Maybe from a very broad viewpoint, it can be viewed as recycling, but this "recycling" takes far more energy, materials and equipment than conventional recycling does. The polymer first has to be heated (far hotter than the melt point) and held at temperature to form the monomers, then the monomers have to be purified (you really don't expect 100% yield, do you?) and then the monomers, with a catalyst have to polymerized. Only then can the polymer pellets be melted and processed. Compare that to conventional recycling: heat the polymers and process them.

If a commercial entity was using this verbiage in advertising, they should expect a Cease and Desist letter in short order from their competitors and/or the government. So how come academia can get away with it?

Previous Years

January 5, 2015 - Time's "Person of the Year" - and Plastics

January 5, 2011 - ANTEC Bound

January 5, 2010 - Amusing Names for Rheology Models

Monday, January 04, 2016

What is the motion of one molecule diffusing?

I survived my first semester as a professor. I really enjoyed it and am looking forward to the next semester.

The only complaint that I had was with the text. We are using "Chemistry - The Central Science" by Brown, LeMay et al. and it drives me nuts at times. Such how it only mentions 3 states of matter - solid, liquid and gas - and overlooks plasmas. Plasmas are not some exotic state of matter completely void of chemistry. Light a Bunsen burner and you have a plasma. It's possible that one or more the students has seen a plasma TV as well. To not mention plasmas is really surprising, especially since the text has no problem in mentioning more esoteric topics, such as Noble gas compounds and ionic compounds.

The section on polymers has too many mistakes to even list, but I think I did a good job of keeping those thoughts to myself.

But what really had me livid (and my students will verify this since it was I spent time in lecture on it, covered it again in the chapter synopsis and even asked about it on the final exam) is this illustration:
The expression "throwing out the baby with the bathwater" has never been more aptly applied.

This figure is a snippet of a random walk and as such, the molecule pictured is most likely to end up right where it started. The molecule is bouncing around at random - there are no signs to indicate which way it is suppose to diffuse and so a single molecule by itself won't diffuse. To call a random walk "diffusion" is a horrible misrepresentation of diffusion. A single molecule won't diffuse anywhere. It will just wander around at random and go nowhere.

So then how do we get diffusion from a collection of random walking molecules? Diffusion is the result of concentration gradients - differences in concentration over a distance. If there is a higher concentration of molecule A on the left and a smaller concentration of molecule A on the right, the odds are better (and yes, diffusion is the result of statistical phenomena) that more molecules from the left will move to the right than from the right to the left since there are more A molecules on the left. There is nothing special about this. The molecules on the left have no clue that they should go to the right - it's just that since there are more of them on the left than the right, they are more likely to overwhelm the molecules on the right moving to the left. But at all times, molecules on the left are each moving to the right and even further to the left while molecules on the right are moving to the left and even further to the right. They have to move in both directions since they are moving randomly without any guidance. The diffusion we observe is based on the statistical outcome of this game of chance and nothing more.

Over time, diffusion lessens the gradient which means that diffusion will lessen over time until eventually the gradient is gone and so is the diffusion. No gradient, no diffusion.

So how can Figure 10.18 above illustrate diffusion when there is only a single molecule in it? It can't. It's not possible. Even if the other molecules were added to the picture, there would still be no diffusion without a concentration gradient. The Zen koan asks "what is the sound of one hand clapping?" to which there is no answer. This picture asks "what is the motion of one molecule diffusing" to which there is no answer, despite the authors claiming to have one.

Previous Years

January 4, 2021 - How will the Law and Chemistry Interact? - The Sheri Sangji Case

January 4, 2011 - Extruder Philosophy

Janaury 4, 2010 - A new year, a change to the comments