Applying the principles of green chemistry to achieve a more sustainable polymer life cycle

This mini-review highlights how many of the principles of green chemistry can be used to make polymers more sustainable. The use of renewable feedstocks has grown enormously in recent years including use of bio-derived monomers and modifications of natural polymers such as carbohydrates. Polymers are also being designed to allow entry into the circular economy especially where triggered depolymerization (e.g. catalytic recycling to monomer) can occur, which can allow easy separation from other plastics in a mixed waste stream. Computational studies and reaction monitoring are useful in identifying and understanding reactivity trends for polymer synthesis and degradation. Solvent-free reactions, including mechanochemistry, can be employed to reduce process mass intensity and environmental impacts. Use of standard polymer degradation conditions (e.g. ISO standards) and life cycle assessments, in particular hot spot analyses, should be encouraged in order to accelerate progress in this important field.