Polymers: long chains of molecules, like beads strung together into a necklace. The twentieth century was the era of the synthetic polymer – acrylics, polystyrene, epoxies and synthetic rubbers; Bakelite, Teflon, Nylon and Neoprene – it’s hard to imagine our world without them.
However, there are thousands of naturally-occurring polymers, or biopolymers. Proteins and carbohydrates are biopolymers, composed of long strings of amino acids or sugars, respectively. Humans are giant masses of biopolymers, from our fingernails (keratin) to our DNA. Trees, shrubs, grasses – all biopolymers.
The manufacture of most synthetic polymers relies on petroleum. As everyone is aware, we’re rapidly depleting our stores of oil. So scientists are turning their attention back to biopolymers, necessity being the mother of invention and all that.
This has led to things like edible packaging, medical implants that dissolve in the body (saving the patient from a second operation), corn-based building materials, and so on. The new biopolymers are based on materials like corn starch, cellulose and vegetable oils. Scientists are even investigating whether spider silk and the exudates of various bacteria can be used to wean us off our reliance on fossil fuels.
Cost and manufacturing limitations are two factors affecting the growth of biopolymers. We’ll also need to consider how they degrade – for example, will degrading bioplastics give off large amounts of methane?
It would be odd if after a century of plastic we returned to cellulose acetate, animal glue and starch paste…