Application of PVC cable

The improvement of aging resistance of PVC plastic mainly depends on the role of heat stabilizer, antioxidant and light stabilizer. For PVC wire and cable, due to the addition of plasticizer larger. 

So the anti-aging properties of plasticizers and plasticizers also have a great relationship, with the use of different plasticizers, aging resistance is also a big difference.

For the plasticizers, containing unsaturated fat radical, ether, thioether, benzyl and chlorine atoms, which are generally poor in weather resistance, and the weathering properties of phthalates and alkylaryl phosphates are good. 

Epoxy plasticizer can not only prevent the processing of products when the color, but also make the products get good weather resistance.

High temperature plasticizer oxidation reaction quickly, the performance of PVC plasticizer has a great destructive, so that performance is reduced, and produce odor. 

PVC in the oxidation process once the double bond, the decomposition of unsaturated polymers like the same as the role of self-catalytic acceleration, resulting in significant color, weight loss, performance and other intuitive changes.

The role of antioxidant?

In general, the ester plasticizer is thermally decomposed at a temperature of about 200℃, and the antioxidant can prevent the ester from oxidizing the generated peroxy radicals and hydrogen peroxide, making it difficult to produce water, thereby preventing the hydrolysis of the esters. 

The acid value is not increased and the further oxidation of the plasticizer is prevented. Poor weather resistance of the plasticizer its decomposition temperature is lower, more complex decomposition products, the general adverse effects heavier. Experiments show that the addition of antioxidants can make high plasticized PVC anti-aging properties and volatile significantly improved. Therefore, in the wire and cable, especially in high-temperature cable must be added a certain amount of antioxidant.

Join the antioxidant, first it can prevent the PVC in the process of thermal oxygen degradation, the second is to prevent the oxidation of plasticizer. PVC cable materials commonly used antioxidants are bisphenol A, antioxidant CA, antioxidant 1010, DLTDP, DMTP, DSTDP, triphenyl phosphite, diphenyl-octyl phosphite and so on.

Bisphenol A is cheap, but the antioxidant efficiency is low, and it is effective only the temperature under 100℃; and bisphenol A can not be used in environmentally friendly products. Antioxidants 2246,264 have discoloration problems, anti-oxygen efficiency is not high. 

It is reported that 4,4'-thiobis (2-methyl-6-tert-butylphenol) and octylated diphenylamine and antioxidant BLE (diphenylamine-acetone condensate) are more effective in antioxidant oxidation in PVC. At present, some of the main and auxiliary antioxidant varieties such as antioxidants 215,225, there are more applications, a better antioxidant effect.

Antioxidant in PVC wire and cable in the amount of the general is about 0.1 to 0.5%, for the application of some weather resistance plasticizer formulations, the amount of antioxidant should be appropriate to increase the recommended dosage of 0.3 to 1.0%.