The Studies On Toughening Of Rigid PVC At Low Temperature

Polyvinyl chloride（PVC）is a kind of important polymer materials,which can be widelyused in many applications, such as agriculture, industry, building, electric power, automobileand so on. Howerver it also has some serious shortage limiting the further applications, forexample, rigid PVC belongs to brittle material, which is very sensitve to notch，and the impactstrength is especially poor under low temperature conditions.Therefore, it has an importantpractical significance to toughen rigid PVC composite under low temperature conditions.Firstly, the effect of five different kinds of inorganic fillers (including CaCO3, SiO2,Kaolin, HNTs and MMT)and three different kinds of elastomers (including CPE, ACR andMBS)on the mechanical properties, processing properties, thermal properties, microstructureof rigid PVC was investigate. The results show that Kaolin has a better ability to toughenrigid PVC at0℃and-15℃than the other four kinds of inorganic fillers. The inorganicfillers can improve the thermal stability of rigid PVC material, but they have a bad effect onthe processability. Among three kinds of elastomers, the abilities to improve impact strengthof PVC composite from high to low is MBS,CPE,ACR. The addition of elastmors has adisadvantage on the thermal properties.Secondly, in order to improve the interfacial compatibility between Kaolin and PVCmatrix, Kaolin was modified by silane coupling agent KH570and titanate coupling agentNDZ201. Then the coupling agent modified Kaolin was added to the PVC matrix. Theproperties and structure of the rigid PVC material were investigated. The results show thatNDZ201has a better modifying effect on Kaolin than KH570. When4phr NDZ201modifiedKaolin was added to the rigid PVC matrix, the impact strength reached the maximum.Moreover, NDZ201modified Kaolin can also improve the thermal properties of composite.Finally, modified Kaolin hybrid particle was prepared by emulsion polymerizationmethod. Moreover, the structure and properties were characterized by Sediment volume,surface contact angle, FTIR, TGA. The results show that butyl acrylate(BA), methylmethacrylate(MMA) formed the chemical bondings wiht Kaolin, and improve the interfacialcompatibility between Kaolin and PVC matrix. Modified Kaolin hybrid particles/PVCcomposites were prepared by two-roll mill processing, and then the effects of modified Kaolinhybrid particle contents on the mechanical properties, themal stabilities, dynamic mechanicalproperties, processing properties were investigated. The results show that the impact strenghth reached the maximum, when8phr modified Kaolin hybrid particles were added into PVCmatrix. The vicat temperature softening point and heat deflection temperature increased afterrigid PVC material filled with modified Kaolin hybrid particles.