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

5 comments:

Joe Q. said...

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?

Because the stakes are so small!

John said...

Sayre's Law!

Joe Q. said...

I knew it had a name...

stevo said...

To be fair to the paper
1. Direct recycling is often not possible with plastics because of additives (colourants, processing aids, antioxidants, UV protectants...) or deterioration during use so you end up producing mix scrap rather than new high performance material. In many cases it is simply better to turn it back to the monomer and start again (or burn or bury it)depending on cost.
2. The polymer can be degraded to monomer at room temperature
3. Many different architectures (cyclic, star, branch) are possible with this method
4. The polymerisation can be carried out under mild conditions as opposed to the extreme conditons in the literature

This plastic is unlikely to set the world on fire, but the article is well done and well worth publishing. The Hype is a different thing but that is usually driven by university press offices rather than the researchers themselves.

stevo said...

Oh and I forgot the most important aspect. By hydrolysing the polymer you can make GHB, a potent date rape/party drug. Bound to be a commercial success.