Synthesizing plastics is a very active field. There are many scientists, chemists and material scientists, that create and study new types of plastics.

Plastics, also called polymers, are made up of many molecules that are chained together. These individual molecule units are called monomers. The properties that the plastic possess is based on the type of monomers used, how they are chained together, and the length of the chain (this is a simplification, there are so many things that can change the properties such as how the individual chains of polymers orient themselves amongst each other).

The particular property that you’re interested in (biodegradability) is highly dependent on how the individual monomers are connected to each other.

Biodegradable plastics tend to have monomers that are bonded together by hydrolyzable bonds, which are bonds that can be broken by a reaction with water molecules. So scientists can design plastics with these bonds and by changing the type of monomers they use, they can tune the mechanical properties (how hard the material is, how bendable, etc.) of the plastics they make.

Scientists get a lot of inspiration from nature in their design of biodegradable plastics. At UCSB, for example, Professor Megan Valentine’s research group draws inspiration from mussels and have mimicked the chemistry of mussels to create biodegradable plastics that have the same strength as mussels.

Unfortunately, biodegradable plastics tend to be more expensive to make than traditional plastics or they do not have desirable mechanical properties or chemical stability so it’s difficult to completely rely on biodegradable plastics replacing all traditional plastics. I think one very exciting avenue of research that addresses this issue is engineering enzymes and microorganisms to break down traditional plastics at a faster rate.