Preparation And Modification Of Polyvinyl Chloride Composites

Poly(vinyl chloride)(PVC)resin has a wide range of applications in the plastics industry due to its low cost,excellent processing performance and good chemical stability,but the defects such as poor thermal stability,easy degradation and poor corrosion resistance,limit the further development of PVC.The mechanical properties,heat resistance and solvent resistance of the PVC resin can be improved by crosslinking of the PVC.In the present work,the problems of high cross-linking degree,poor wear resistance and insufficient toughness in cross-linked polyvinyl chloride paste resin(c-PVC)with traditional chemical cross-linking methods were studied.It was of great significance for further broadening the application of PVC materials.The following three aspects are studied:Three kinds of unsaturation treminated PUA were synthesized by polyether polyols,IPDI and HEMA.PUA/PVC composites were prepared by organic peroxide crosslinking method,and the structure and properties of the composites were characterized by FT-IR,SEM,TGA and DSC.The curing reaction at high temperature and its kinetic model were discussed.The effects of various factors on the thermal,mechanical properties and wear resistance of PUA/PVC composites were investigated.The results show that the proper amount of PUA can improve the toughness,wear resistance and thermal stability of the composites.The cross-linking modification of c-PVC material was carried out by pentaerythritol tetraacrylate(PET4A),and the effects of different cross-linking agents and TMPTMA/PET4 A composition ratios on the mechanical properties and wear resistance of the composites were studied.It was found that PET4 A could promote the cross-linking reaction and improve the strength of the composites.When DTBP was used as the initiator and the TMPTMA/PET4 A composition ratio was 0/100,the tensile strength and elongation at break increased by 34.0% and 62.0%,respectively,and the hardness and wear resistance increased by 15.9% and 43.9%,respectively.The PUA/PVC materials were blended and modified with few layer graphene(FLG)and graphene oxide(GO).FLG and GO were characterized by AFM,SEM,FT-IR and Raman.The effect of FLG or GO contents on the mechanical properties of PUA/PVC composites was studied.The results show that the tensile strength and elongation at break of FLG/GO-PUA/PVC system are the highest when the content of FLG and GO is 0.5wt% and 0.75wt%,respectively,which is attributed to the uniform dispersion and strong interaction between FLG/GO and PVC/PUA.