Stability And Electrical Properties Of Pvc

Stability
The softening point of PVC resin is low, about 75-80 ℃, and the embrittlement temperature is lower than - 50~- 60 ℃. The long-term use temperature of most products should not exceed 55 ℃, and the special formula can reach 90 ℃. If the PVC resin belongs to the linear structure of the head to property interface, and there is no branch chain and unsaturated bond inside, although the C-Cl bond energy is relatively small, the stability of the PVC resin should also be relatively high. But even if the PVC resin with high purity is kept above 100 ℃ for a long time or is exposed to ultraviolet radiation, hydrogen chloride gas will start to escape. It shows that there are sharp groups or unstable structures in its molecular structure. The longer the time is, the more the degradation is, and the higher the temperature is, the faster the degradation is, and the faster the degradation is in the presence of oxygen or air.
Electrical performance
Polyvinyl chloride is a polar polymer with high affinity for water and other conductive substances, so its resistance is smaller than that of non-polar polyolefin, but it still has higher volume cathode and breakdown voltage. The polar group of PVC is directly attached to the main chain. Below the glass transition temperature, the dipole chain segment is restricted by the main chain atom of the frozen structure and cannot be moved. Therefore, it does not produce dipole polarization, and can be used as high-frequency insulation material at room temperature. When used for wire insulation, the electrical insulation of suspension resin is 10-100 times higher than that of floating resin. The existence of chloride ions generated by degradation will reduce the electrical insulation.