2014年4月1日星期二

The main ingredient of PVC stabilizer

PVC stabilizer on the original white and gradually turn yellow - red - brown - black. PVC resin decomposition reaction is due to the de-HCL caused a chain reaction, leading to macromolecules strand breaks. PVC heat stabilizers to prevent thermal decomposition mechanism is through the following aspects to achieve. (1) by capturing the thermal  PVC lubricants decomposition of PVC HCl, to prevent catalytic degradation of HCl. The main mechanism of action of lead salts class here, in addition to metal soaps, organic tin, phosphorous lipids and epoxy 2) replacement lively allyl chloride atoms. Metallic soaps, lipids and organic phosphorous tin can here the role of the mechanism. 3) the reaction with free radicals, the radical termination reaction. Organic tin and phosphorous lipid mechanism role here. (4) with conjugated double bond, inhibit growth of conjugated chain. Organotin role and  PVC plasticizer mechanism of epoxy here. (5) the decomposition of peroxide to reduce the number of free radicals. Organic tin and phosphorous lipid mechanism role here. 6) HCl passivation effect of a catalytic metal ion removal. PVC stabilizer with a stabilizer according to several different mechanisms to achieve thermal stability purposes. Composite stabilizer can be divided into the following categories: (1) liquid barium zinc composite stabilizer is generally pale yellow to yellow-brown oily liquid, specific gravity 1.0-1.1, good heat resistance at room temperature, without sulfide pollution, and epoxy plasticizers and stabilizing effect can be improved by, it can activate the foaming agent. 2 main  Polyethylene wax ingredient liquid calcium zinc composite stabilizer nontoxic liquid calcium zinc stabilizers are calcium stearate, castor oil, calcium, zinc stearate, castor oil, zinc and epoxy soybean oil, ultraviolet absorber. Hugh liquid calcium zinc stabilizers are generally used more soluble in organic solvents having a carbon number of less fat fat calcium and zinc. Because of the different components, varied in nature, usually pale yellow to yellow clear oily liquid at room temperature gravity of 1.0-1.05. It is non-toxic PVC stabilizer, mainly for food packaging films, containers leather foam stabilizers.

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