scientists unveil process that makes biodegradable plastics truly compostable

scientists at the university of berkeley have unveiled a new process that makes biodegradable plastics truly compostable. advertised as one solution to the plastic pollution nightmare we’re facing, these compostable plastic bags, utensils and cup lids among others don’t break down during typical composting and contaminate other recyclable plastics. sadly, most of these compostable plastics end up in landfills and remain there as long as normal plastics. 

(main) image UC berkeley photo by ting xu
(above) image by christopher delre

‘people are now prepared to move into biodegradable polymers for single-use plastics, but if it turns out that it creates more problems than it’s worth, then the policy might revert back,’ said ting xu, UC berkeley professor of materials science and engineering and of chemistry. ‘we are basically saying that we are on the right track. we can solve this continuing problem of single-use plastics not being biodegradable.’

UC berkeley photo by adam lau/berkeley engineering

to tackle this problem, scientists at university of california, berkeley, have invented a way to break down these compostable plastics with just heat and water in just a few weeks. the process involves adding polyester-eating enzymes to the plastic while it’s being made. for the enzymes to be protected from untangling and becoming useless, it features a simple polymer wrapping. once exposed to heat and water, the enzymes gets rid of the polymer shroud and starts chomping the plastic polymer into its building blocks. basically, the process allows the polymer plastic to self-destruct.

graphic by christopher delre

‘it turns out that composting is not enough — people want to compost in their home without getting their hands dirty, they want to compost in water,’ xu continued. ‘so, that is what we tried to see. we used warm tap water. just warm it up to the right temperature, then put it in, and we see in a few days it disappears.’

xu believes that programmed degradation could be the key to recycling many objects. ‘imagine using biodegradable glue to assemble computer circuits or even entire phones or electronics, then, when you’re done with them, dissolving the glue so that the devices fall apart and all the pieces can be reused.’

project info:

name: process to make biodegradable plastics fully compostable

led by: ting xu

supported by: department of defense’s army research office

co-authors: christopher delre, yufeng jiang, philjun kang, junpyo kwon, aaron hall, ivan jayapurna, zhiyuan ruan, le ma, kyle zolkin, tim li and robert ritchie of UC berkeley; corinne scown of berkeley lab; and thomas russell of the university of massachusetts in amherst