Recent Commercial Successes in Synthetic Polymers

What it takes to get a specialty polymer to commercial success

I was asking Twitter what I should write about next and over the next few weeks I’ll be trying to write what the people want and first up is this prompt below:

Matthew Kirshner @MattyKirsh

@TPolymerist What was the last successful new plastic/polymer brought to market, and why have very few (any?) novel polymers been brought to market in recent decades?

This got me thinking. We never hear about recent commercial successes in this space because there are two things at work:

1. Massive commodity type advances in synthetic polymer commercialization do not often occur due to low cost and current viability of incumbents.

2. The successes that do occur are often specialties and might only have 1-2 large customers.

This doesn’t mean that these things do not happen, but rather that they do not necessarily take the path that one might expect. First, let’s talk about number 1.

Polylactide or PLA

So polylactide and poly(lactic acid) are essentially the same thing, but the name essentially denotes different routes of synthesis. Polylactide for instance is polymerized by a ring opening polymerization (ROP) of lactide (a lactone made from two molecules of lactic acid) while poly(lactic acid) is made by direct polymerization of lactic acid. Yes, lactic acid, the stuff that is in your body.

Poly(lactic acid) also known as PLA was first polymerized by Wallace Carothers in the early 1900s. DuPont never commercialized the technology because the polymer started to fall apart after exposure to water and humidity. If you are super interested in the history and advancements of this polymer, then I recommend you check out this review by Bob Langer and coworkers. The nature of PLA to degrade overtime into lactic acid, a commonly found chemical in the human body, actually would become a feature. PLA and copolymerization with glycolic acid (to fine tune in-vivo degradation kinetics) would lead to aliphatic polyesters being used in bio-resorbable sutures.

PLA and similar synthetic polymers (e.g., poly(caprolactone) and other copolymers) then started being used more widely in things like bone screws and stents. Thus, the use of a hydrolytically degradable polyesters became quite a business, but the volumes consumed in making things like sutures, stents, and bone screws was miniscule when compared to commodity plastics applications.

Then, in 2003 NatureWorks decided release PLA under the tradename Ingeo(TM) broadly to the public. At this time, there was a lot of sentiment against single use plastics (it’s still around), concern for the plastic gyre in the pacific, and concerns of peak oil and just running out of petroleum. We also get the majority of lactic acid from corn via fermentation and then eventual dimerization to lactide. PLA does sort of solve both the petroleum issue and the degradation issue, but PLA is only degradable under very specific conditions. The best-case scenario we can hope for with PLA is that it turns into carbon dioxide after being composted at an industrial facility, but even this has its problems.

PLA from a consumer-focused use standpoint is essentially the same as other plastics. We could use PLA as a food service container, a water-resistant coating on paper, single use cups, 3D printing filament, and essentially any non-durable application where a rigid plastic is useful. The key to PLA’s usefulness is access to industrial composting and keeping it out of traditional recycling waste streams. Oh, it’s also way more expensive than it’s petrochemical competition.

Polylactide has some good niche uses both in medical and broad consumer applications, but it’s widespread adoption will always be hindered by price and performance. That doesn’t mean it isn’t a success though. NatureWorks has sold over a billion pounds of PLA and is a viable company offering a viable alternative to petrochemical plastics.

Everything old is new again.

Specialty Polymers

The majority of synthetic polymers sold are often the commodity resins such as LDPE, PP, and HDPE. PLA is at best a niche commodity player and it’s not even that new of a polymer, but does that mean synthetic polymer chemistry is not worth pursuing? Definitely not.

Specialty polymers when we get down to it are often custom made for very specific customers. Phenolic resins are a great example of how small tweaks in monomer ratios, cook times, and catalyst selection can produce what feels like nearly an infinite amount of end products. You might think phenol + formaldehyde is quite basic, but rather I urge you to think of every and any type of phenol compound and any aldehyde being used to make a polymer.

Let’s take a look at just some phenols I can think of in a minute or two:

1. Phenol

2. o-Cresol

3. m-Cresol

4. Nonyl-phenol

5. Cashew Nutshell Liquid (Cardanol)

6. Resorcinol

From just these six we could mix/match them and then pair them with a whole list of aldehydes, catalysts (acids + bases), and even amino compounds like melamine and urea. We can get a seemingly infinite amount of complexity, but this complexity is only useful when specific properties emerge. We (polymer chemists) like to call this stuff, “structure-property relationships” and it’s how we can try and relate chemical structure to end physical properties.

A user of a very specialized phenolic resin might be willing to pay a premium for a custom resin if it gives them an edge over their competitors and this might be worth a few years of product development for a specialty chemical company. Figuring out when it’s worth it versus not worth it is a whole different discussion.

Actually, this is the type of business that Zymergen was trying to enter with its polyimide product. I just think that they didn’t fully understand the intricacies of specialty polymer product development and the timelines were just not feasible for their investors. Specialty chemicals are low volume high margin plays that are somewhat risky to make, but once you can capture the volume and gain a few wins then it’s a very difficult business to lose. I should note that it’s not impossible to lose because I’ve seen chemists reverse engineer products and match a C13 NMR with something they made in the lab. Make sure you patent your stuff and that your claims are enforceable.

The best place to try and stay current on specialty polymer commercialization is the CAS number database (accessible via SciFinder). You can see new registrations for specific monomer types and combinations of monomers to make a polymer. but it can be difficult to know if they are actually commercialized. TSCA approval via a pre-manufacture notice (PMN) doesn’t mean a product is commercial and polymer exemption is a way to bypass the (PMN) approval process.

Specialty chemical product development timelines can take years. About 2 years minimum for some and maybe up to 5+ for others. Make sure you have enough runway to get to the finish line. If you are a start-up working in this space, then I wish you the best of luck. Sometimes not knowing how difficult this stuff is can be an advantage sometimes.

Let me know if you need help.

Tony

I don’t have any cool movie or show clips to tie this post too, but here are my current background vibes these days. Monk and Davis.