Photodegradable plastics: end-of-life design principles

Photochemically degradable polymers and plastics are reviewed with an emphasis on the environmental and molecular factors that control the onset of degradation and the rate of degradation. A number of principles are beginning to emerge for the design of viable photochemically degradable plastics. Among the principles discussed are those relating to the effects of chromophores, initiators, antioxidants, temperature, oxygen diffusion into the plastic, polymer crystallinity, tensile and compressive stress, and the absorbed light intensity on the plastic. To obtain a plastic with a controlled lifetime and a specific rate of degradation, many of these parameters can be controlled or adjusted in the design stage of the plastic.