PVC (Polyvinyl Chloride) is an initiator of vinyl chloride monomer (VCM) in peroxides, azo compounds, etc.; or by free radical polymerization under the action of light and heat. Polymerized polymer. Chloroethylene homopolymers and vinyl chloride copolymers are collectively referred to as vinyl chloride resins.

PVC is an amorphous white powder with a low degree of branching, a relative density of about 1.4, a glass transition temperature of 77~90°C, and decomposition starting at about 170°C [1]. The stability to light and heat is poor at 100°C or above. After prolonged sunlight exposure, it will decompose to generate hydrogen chloride, and further autocatalytic decomposition, resulting in discoloration, physical and mechanical properties also rapidly decline, in the practical application of stabilizers must be added to improve the stability of heat and light.