Optimization Of Pvc Resin In The Weak Structure And Thermal Stability Of Oxygen-ray Oxygen

In this paper, structural defects of PVC, such as peroxide groups, carbonyl groups and carbon-carbon double bonds, were investigated by means of FTIR, UV-Visible spectra. The total double bond contents of PVC before and after optimization were determined by analytical method of cataltic bromine addition and changes of the total double bond contents of products obtained after thermal oxidation of PVC were studied. The chloroallyl group contents of PVC were determined by potentiometric titration and the correlation between chloroallyl group content and molecular weight was studied. The white degree dropping of PVC were tested by white degree meter. The rates of dehydrochlorination of PVC were studied by the thermogravimeter. Thermal stability of PVC were further explored.The thermo-oxidation and photo-oxidation stabilization of PVC samples optimized, optimizing and un-optimized from the same factory were studied by the heat following the track method of IR and UV radiation method. Then optimized samples were compared with the contrast samples. The results verified that the thermal stability of PVC decreased with the increase of structural defects contents of PVC . Thus the difference between optimized and un-optimized PVC samples had been investigated.At the same time, the white degree dropping of several samples were tested by white degree meter .The result showed that white degree dropping of all optimized samples were the lowest and the coloured property during the initial heating was the best. The property related to the stereospecific structure of PVC chain.