Affiliation: Cornell University │ Ithaca, New York
Cornell University │ Ithaca, New York
For transformative work at the interface of chemical catalyst design and polymer science leading to novel ways of making biodegradable and recyclable plastics.
A blue recycling bin at the curb carries an optimistic promise: yesterday’s packaging will become tomorrow’s raw material. Yet, once those bottles, tubs, and films arrive at a sorting facility, optimism collides with chemistry. Many plastics that look similar are made from different molecular ingredients, and some of the most common types refuse to mix. The result is a stream of waste that is difficult to reuse at high quality and a primary reason that most of what we put into our recycling bins ultimately ends up in a landfill. This is the world Geoffrey Coates has spent his career trying to redesign.
Coates builds catalysts and polymer synthesis strategies aimed towards a challenging goal: plastics that work beautifully in daily life, then return to use again without becoming trash.
To see the problem up close, consider two workhorse materials: polyethylene and polypropylene. They are everywhere, from milk jugs and detergent bottles to caps, containers, and flexible packaging. They also tend to travel together from the blue bin to the recycling plant, but they are, in a practical sense, incompatible. When melted into the same stream, polyethylene-rich and polypropylene‑rich regions separate rather than blend, producing a weak, brittle material. Even a few percent of one polymer mixed into the bulk of the other—what recyclers often call contamination—can be enough to spoil the final product.
Coates helped change that story by treating mixed plastics like an engineering problem. In a 2017 collaboration with researchers at the University of Minnesota, his team developed a specially designed “multiblock” polymer additive that encourages polyethylene-rich and polypropylene-rich regions to mix. Added in small amounts, it acts like a molecular glue between the two materials, producing a tougher, stronger blend instead of a disappointing compromise.
What makes that idea powerful is that it respects how plastics behave in the real world. Recycling is rarely neat. Bales of material contain variation in grades, dyes, fillers, and histories of exposure to heat and sunlight. A practical solution has to tolerate that messiness. The multiblock “glue” approach points toward something closer to the way metallurgy works, where alloying elements can convert mixtures into useful materials. Coates and colleagues have described this as a path to “plastic alloys” that keep desirable properties while expanding what can be recycled together.
Recycling, though, is only one side of Coates’ vision. The other is designing plastics that can be returned to nature or taken apart cleanly at the end of life. Many polymers are durable because their backbones are strong, which is exactly what makes them linger for decades. Coates’s work often begins earlier in the life cycle, at the moment a polymer is created, by using catalysts to control structure and therefore control destiny.
In practice, that can mean creating polymers that behave like familiar plastics during use, yet contain built-in “release points” that allow them to be chemically recycled or safely degraded when the time comes. One example from Coates’s research community is the pursuit of polyolefin-like materials that incorporate chemically cleavable links, offering a route to break a plastic down into useful building blocks rather than downcycling it into waste materials.
Coates’s group and collaborators have published work along these lines, aiming for materials that preserve performance while improving end-of-life options. Coates has also engaged the idea of upcycling, where waste plastics become “feedstocks”—the key ingredients—for new, higher-value chemicals instead of being buried, burned, or mechanically degraded. The point is to stop drilling for new feedstocks, which typically come from fossil resources, when a vast supply is already sitting in landfills and incinerators.
The through line in all of this is Coates’s ingenuity with catalysts. A catalyst is a kind of guide for molecules, directing them to connect in one way instead of another. Small changes in those connections can determine whether a polymer becomes tough or flexible, long-lived or degradable, easy to separate or impossible to sort. Coates’s career has been defined by harnessing that control for sustainability. It is also why his work has crossed easily from academic chemistry into the real world. He is a scientific co-founder of companies such as Novomer, which uses novel catalysts to produce environmentally responsible polymers and chemicals.
There is a particular kind of hope embedded in Coates’s work. It is not the hope that society will simply use less plastic tomorrow. It is the hope that the materials themselves can be redesigned so the best version of plastics does not end as pollution. By finding ways to “weld” mixed commodity plastics into strong new materials, by advancing polymers that are recyclable by design, and by pushing toward biodegradability without sacrificing performance, Geoffrey Coates has helped outline a future in which efficient recycling is no longer aspirational. It is engineered.
Born in Evansville, Indiana, Coates earned a chemistry degree from Wabash College and a Ph.D. in organic chemistry from Stanford, studying stereoselective catalysts. After an NSF postdoctoral fellowship at Caltech, he joined Cornell’s faculty in 1997, where he has pursued catalyst-driven polymer science ever since.
Information as of March 2026