Then the so-called bio-degradable plastics (bio-plastics) came to the market as an alternative. Most of these products require the production or harvesting of virgin biomass, such as trees or biomass crops, both of which have an environmental impact that isn't sustainable at our current rate of plastic consumption.
A new type of bio-plastic is in the work using chitosan. Chitosan is made by treating shrimp and other crustacean shells with the alkali sodium hydroxide. It can be broken down into benign, even helpful, components in the soil in about two weeks.
According to researchers at Harvard's Wyss Institute there is an urgent need in many industries for sustainable materials that can be mass produced. Their scalable manufacturing method shows that chitosan, which is readily available and inexpensive, can serve as a viable bio-plastic.
The chitosan polymer developed initially had a shrinkage problem that kept it from maintaining its shape after the molding process, but the team found that by adding wood 'flour' (a wood processing waste product) to the mix, the new bio-plastic could be molded into a 3D form with "impressive precision."