Managing photodegradation of poly(vinyl chloride)

Poly(vinyl chloride) is applied in almost every aspect of our lives because it is easily modified and inexpensive. However, it is characterized by poor heat and UV resistance due to the presence of some abnormal structures that originate from synthesis. Such groups include unsaturated double bonds, allylic chlorines and branch points. Addition of thermal stabilizers is, therefore, required to prevent thermal degradation during processing (which usually occurs at temperatures of 150–180°C). Commonly used thermal stabilizers for PVC belong to one of four categories: lead salts, metal soap, organotin compounds and some auxiliary stabilizing materials.