tailieunhanh - Crosslinking of rigid poly(vinyl chloride) by a peroxide in the presence of Trimethylolpropane trimethacrylate

This paper presents the results of study on crosslinking of rigid poly(vinyl chloride) (PVC) by 1,1-di-(t-amylperoxy) cyclohexane (DAPC) in the presence of trimethylolpropane trimethacrylate (TMPTMA). Gel content of the PVC samples is increased with increasing concentration of TMPTMA and peroxide DAPC. Ultimate tensile strength (UTS) of the PVC samples is rised with increasing concentration of TMPTMA. Maximum UTS of the PVC samples is achieved with phr peroxide DAPC for every investigated concentration of TMPTMA. Formation of TMPTMA network, crosslinking and grafting of PVC chain radicals on to TMPTMA network are able to improve the gel content, UTS at low - and elevated temperatures and modulus of rigid PVC material. | Journal of Chemistry Vol. 41 No. 3 P. 127 -132 2003 CROSSLINKING OF RIGID POLy VINyL CHLORIDE By A PEROXIDE IN tHE PRESENCE OF TRimEtHyLOLPROPANE tRImEtHACRyLAtE Received 18-2-2003 THAI HOANG1 NEIL VARSHNEY2 institute for Tropical Technology NCST Vietnam institute of Polymer Technology and Material Engineering Loughborough Uni UK SUMMARY This paper presents the results of study on crosslinking of rigid poly vinyl chloride PVC by 1 1-di- t-amylperoxy cyclohexane DAPC in the presence of trimethylolpropane trimethacrylate TMPTMA . Gel content of the PVC samples is increased with increasing concentration of TMPTMA and peroxide DAPC. Ultimate tensile strength UTS of the PVC samples is rised with increasing concentration of TMPTMA. Maximum UTS of the PVC samples is achieved with phr peroxide DAPC for every investigated concentration of TMPTMA. Formation of TMPTMA network crosslinking and grafting of PVC chain radicals on to TMPTMA network are able to improve the gel content UTS at low - and elevated temperatures and modulus of rigid PVC material. I - INTRODUCTION Crosslinking of poly vinyl chloride PVC is an effective way which can improve some properties of polymer material especially at elevated temperatures. Many authors have published papers relating to the irradiation crosslinking of PVC polyethylene PE with different irradiation doses in the presence of crosslinking monomers 1 - 4 . At suitable irradiation doses the gel content tensile properties penetration resistance and softening temperature of crosslinked PVC compounds are clearly enhanced. However this method demands complex and high - price machines or instruments. Recently chemical crosslinking of PVC has been studied using organic silan as a crosslinker 5 - 7 . Peroxides are used for crosslinking of PVC and PE 8 - 11 . PVC by itself has a low crosslinking yield when a peroxide initiator is used. Measures to promote the crosslinking capability of PVC include grafting PVC chains with polyfunctional .