Controlled - Lifetime, Environmentally Degradable Plastics Based on Conventional Polyethylenes

摘要

In order to be considered environmentally degradable, a plastic must disintegrate mechanically, which means that the molecular weight of the molecules must be reduced, and then these molecular fragments must be microbially susceptible. Given that polyethylenes are microbially inert, other degradation mechanisms must be called into play, at an appropriate time, to convert hydrophobic, high molecular weight polyethylene materials into water-wettable, friable substances containing much smaller molecules. It is known that the abiotic oxidative degradation of polyethylene film to produce oxidized molecular fragments having, on average, a molar mass reduced by a factor of ten or more can be accelerated without altering the products. It is also known that such products are biodegradable by aerobic micro-organisms.