New Princeton Class Tackles the Plastic Problem

From the accumulation of plastic in landfills that prompted plastic bag bans to the recent headlines about toxic components of plastic food containers and utensils, it’s clear, at least to Emily Davidson, that the plastics “problem” is “one of the biggest challenges of our time.”

But Davidson, an assistant professor of chemical and biological engineering who leads a lab on campus focusing on polymer design, synthesis, and assembly, also knows “there’s a lot of real benefits that plastics bring to our lives.”

That’s the main thrust of Davidson’s new class, Plastics, Profit, and People: How Science & Society Can Strive for Sustainability, which is cross listed in engineering, environmental studies, and the Council on Science and Technology. The class combines technical knowledge of materials with related information on the history, economics, and sociology of plastics.

During one lecture, Davidson posed this real-life scenario: A chocolate company wants to increase the amount of recycled content in its packaging without sacrificing performance (recycled plastic often performs more poorly than “virgin” plastic). In small groups, students debated the risks of introducing additives to a food product.

“This is the real trade-off that [companies] have to make,” Davidson said.

Davidson designed the class to be accessible to all majors, and the 33 enrolled students span from freshmen to seniors.

Charlotte Selover ’25, a chemistry major, said she thinks hearing other perspectives in the classroom “is good because I’ve always approached the plastic conversation from my field.”

Selover was particularly interested to read about early uses of plastics; for example, Indigenous people used naturally derived polymers, such as cellulose, to make rubber balls for entertainment and rituals. Another favorite reading followed a man attempting to live plastic-free for a day, detailing all the substitutes he had to make.

Rounding out the readings and Davidson’s lectures are three labs that introduce students to the properties of plastics, and a few field trips, including visits to the University’s S.C.R.A.P. Lab and a nearby materials recovery facility, which processes recycled materials. She is also bringing in guest speakers: an investigative science journalist, a local politician who supports plastic bag bans, and an employee of chemical and consumer goods company Henkel who works with sustainable products.

For the final assignment, students will work in groups to create posters that propose solutions to a plastics problem of their choice.

Selover says there is “no one-size-fits-all solution” to environmental problems like plastic, because it can be easy “to say that we need to impose regulations … but it’s not always feasible for every sect of society to just stop using certain materials and resources.”