PVC heat stabilizer is an additive that can prevent or reduce polymer degradation or cross-linking due to heat during processing and use, and prolong the service life of composite materials.
PVC stabilizers can be classified into bases, fatty acid soaps, organotin compounds, composite heat stabilizers, and pure organic compounds according to their main components.
The base stabilizer combines the base inorganic and organic acid lead salts. It has excellent heat resistance, weather resistance and electrical insulation, low cost, poor transparency and certain toxicity.
Fatty acid heat stabilizers are compounds composed of fatty acid roots and metal ions. Its performance is related to the types of acid radicals and metal ions.
The organotin heat stabilizer can form a ligand with the unstable chlorine atom in the polyvinyl chloride molecule, and the carboxylate group of the organotin is replaced with the unstable chlorine atom in the ligand. It has high stability, good transparency and excellent heat resistance.
The composite heat stabilizer is a liquid or solid compound based on salt-based or metal soap and a compound based on organic tin. Organic fatty acids, naphthenic acid, oleic acid, benzoic acid and salicylic acid are commonly used organic acids.
In addition to a few main stabilizers that can be used alone, organic compound heat stabilizers also include high-boiling polyols and phosphites. Phosphite is often used in combination with metal stabilizers to improve the weather resistance and transparency of composite materials and improve the surface color of products.