Plastic heat stabilizer by category

 Heat stabilizers are a class of polymers can prevent or reduce the heat in the course of processing and degradation or cross-linking occurs , extending the life of composite additives . Usual stabilizers can be divided into categories according to the main component of salt , fatty acid soaps , organotin compounds, heat stabilizers, and the pure compound classes of organic compounds . 1 ) Heat stabilizer salt : salt stabilizer is the Stabilizers for pipe  combination of the " base " of lead salts of inorganic and organic acids , such stabilizer having excellent heat resistance , weather resistance and electrical insulating properties , low cost transparency is poor, there is a certain toxicity, dosage is generally 0.5% to 5.0 %. ( Source Global polyurethane network ) 2 ) a fatty acid based heat stabilizer : Such a thermal stabilizer is a compound of a fatty acid composition of roots and metal ions , also called metal soap heat stabilizers , acid groups , and its performance and the kind of metal ions , generally the amount of 0.1% to 3.0%.
3 ) organotin heat stabilizers : class PVC heat stabilizer molecule with chlorine atoms to form unstable ligand and the ligand organotin carboxylate group and a chlorine atom unstable replacement . Features such heat stabilizers are high stability , good transparency , heat resistance, the downside is expensive.
 4 ) Composite type heat stabilizer : Such a thermal stabilizer is a metal salt or soap as a kind of liquid or solid based compound and an organic tin -based compound , wherein the metal salts are calcium - magnesium - zinc , barium - calcium - zinc, barium - zinc and  PVC plasticizer barium - cadmium ; common organic acids such as organic acids, naphthenic acid, oleic acid, benzoic acid and salicylic acid. 5 ) an organic compound heat stabilizer : Such a heat stabilizer except for a few primary stabilizers may be used alone (mainly nitrogen containing organic compound ) , but also a high boiling point include polyhydric alcohols and phosphites , phosphites often stabilizer, the metal can improve the weather resistance, transparency of the composite material , to improve the surface color of the article. Mechanism of action of a thermal stabilizer 2PVC
1 ) absorption and HCL, inhibit its auto- catalysis. Such stabilizers include lead salts , organic acid metal soaps , organic tin compounds, epoxy compounds, phenol salts and metal thiolate . They can react with HCL , HCL off PVC suppression response. 2 ) replacement of PVC molecules suppress unstable allylic chlorine atom de PVC. Organotin stabilizers such as a chlorine atom with an unstable ligand binding molecule PVC polyene structure with an addition reaction , a ligand , a chlorine atom with an unstable organic tin substitution 3 ) , formed in the destruction of a large conjugated system reduce coloration . Unsaturated acid salts or esters containing double bonds , and the PVC molecules conjugated diene double bond addition reaction , thereby destroying the structure of the conjugate , inhibiting discoloration. 4 ) capture free radicals and prevent the oxidation reaction . As the phenolic heat stabilizer can be added to block off the HCL, because Polyethylene wax  phenol can be given by H atoms and radical degradation of PVC macromolecular radical coupling , not react with O2 forming material , and a heat stabilizing effect . Such a thermal stabilizer , one or both may have several roles .
 Ideal for PVC heat stabilizers should be a versatile substance , or a mixture of some of the material, they are able to perform the following functions : First, replacement lively, unstable substituents ; second is to absorb and neutralize the release of PVC processing HCL, eliminating autocatalytic degradation of HCL ; Third neutralize or inactivate catalytic degradation of metal ions and other harmful impurities ; Fourth, through various forms of chemical reactions can be blocked unsaturated bond continues to grow , inhibiting degradation coloring ; five is the best shield against ultraviolet protective effect . Generally, heat stabilizers according to their performance with the use of special , very little is used alone , but most of the species in a powder form , some of which are highly toxic chemicals. For ease of use , to prevent dust poisoning, reduce toxic substances or substitute non-toxic substances, at home and abroad in recent years developed a wide variety of composite stabilizer , for example , the world famous German brand composite stabilizer Bear series , the United States , Germany, Japan , Netherlands and other countries , or organotin compound organotin stabilizers have a considerable market in China . Therefore , the development of China's efforts to promote the use of high efficiency, low cost , no dust pollution and toxic or low toxicity of new composite stabilizer is an urgent need for the development of China's plastics industry .