The Study Of Synthesis And Property Of The Nano-crosslinked Particles Of PVC Heat-resistant Modifier

With the development of industrialization and high performance of the PVC, the people have gave more and more attention about the heat-resistent modification. The heat-resistant agent was synthesized by emulsion polymerization with styrene(St), methylmethacrylate(MMA), divinylbenzene(DVB) as the basic material. It has high glass transition temperature with a typical core-shell structure. The core nucleus is the rigid particles with crosslinking agent(DVB), and the shell is the copolymer with St and MMA, which has well consistency with PVC. Blends with PVC will increase the heat-resistant temperature of PVC.The toughness of PVC will decline by blending with the heat-resistant modifier. Usually add some impact modifier as compensation. To find a balanced value with the heat-resistance and the impact properties, we can regulate the usage of the impact modifier and heat-resistant modifier.The heat-resistance and the impact properties of PVC/heat-resistant modifier blends and PVC/MBS/heat-resistant modifier blends was tested by the Vicat softening point tester and Hap torque rheometer. The mechanical property was analysed by impact testing machine and universal electronic testing machine. The morphology of the impact cross-section and the thermodynamic properties were characterized by SEM and the DMA.The experimental results show that:(1) The core-shell structure, nano-scale heat-resistant modifier with high glass transition temperature could be synthesized using latex polymerization. (2) The plasticizing properties and heat resistance had been improved by adding heat-resistant modifier in PVC, but the toughness reduced. (3) Adding a defined amount of impact modifier MBS in PVC/heat-resistant modifier binary blends could improved the toughness of blends effectively. (4) Good impact strength and heat-resistant PVC material could be obtained by adjusting the dosage of heat-resistant modifier and MBS.