Environmental Aspects of Initiators for Plastic Manufacture and Processing

Abstract

Organic peroxides, persulfates, carbon–carbon initiators, and azo initiators generate radicals mainly by thermal or redox decomposition. Decomposition products mostly remain in the polymer or become incorporated in the polymer chain. Solvents, temperature, concentration, and reaction partners vary the type of decomposition products generated. Uncontrolled decomposition could cause fire and explosions. Storage and transport therefore need temperature control, which is also necessary to maintain quality. A small number of initiators cause toxicity problems and have been mostly eliminated. The FDA and BfR produce a positive list for food package polymers. Most polymers being manufactured require low-odor initiators. Benzene, PCBs, aromatic amines, or heavy metals cause changes in initiator type used as well as in processing conditions.