Defined PVC heat stabilizers
2013-12-17 by seoer8
Broadly speaking, those who can improve the thermal stability of the polymer additives are known as heat stabilizers. Due to poor thermal stability of PVC, so most of the world are used in PVC one pack stabilizer . So, usually said
PVC stabilizer means of PVC heat stabilizers and copolymers.
General thermal stabilizers according to the classification of chemical components, basic lead salt may be, metal soaps, organic tin, epoxy compounds, phosphites, polyols and the like. In terms of the role of size can be divided into the main PVC stabilizer stabilizer and auxiliary stabilizer. Auxiliary stabilizer itself is only a small or no stabilizing effect on the thermal stability effect, and it is the main stabilizer and having a synergistic effect; primary stabilizers are generally metal-containing heat stabilizer. The epoxy compounds, phosphite, polyols such as pure compounds are generally used as an auxiliary stabilizer.
To achieve good stability because PVC pvc often need to use a variety of thermal stabilizers, so that some product PVC stabilizer is compounded by the plurality of components, becomes a composite stabilizer, a stabilizer such as barium-cadmium, barium zinc stabilizer etc. These composite stabilizer usually has joined the PVC processing lubricants and other additives needed to facilitate the users. Many varieties of composite stabilizer, powder, paste, liquid, three forms [1]
(1) absorption of hydrogen chloride
Me (OOCR) 2 + 2HCl === MeCl2 + 2HOOCR
Wherein Me is: Pb, Ba, Cd, Ca, Zn, Sn, Sb, Mg, Sr and the like.
(2) the elimination of unstable chlorine atoms replaced by chlorine atoms or eliminate unstable.
(3) to prevent the auto-oxidation of PVC in the heat of oxygen and shear stress, oxidative degradation can easily be O2.
(4) maleic acid salt or to inhibit or eliminate the double bond becomes shorter and less.
keywords: pvc-additive
