Synthesis And Application In PVC Of Acrylic Resin(ACR)

Polyvinyl chloride (PVC) is one of the five thermoplastic general plastics and it is widely used in various fields. Due to its superior durability and comprehensive properties and unique technical and economic characteristics, PVC has broad prospects. In the manufacturing process of PVC materials, especially PVC alloy with high toughness, toughening components, that is impact modifier, need to be added; PVC is a kind of polar polymers with high melt viscosity, poor thermal stability, and it is not easy to be plasticized in high temperature. Therefore, to improve the processing performance of non-plasticized PVC with high intensity, the plasticizing processing aids need to be added. In this study, according to the requirements of PVC materials with high performance Polyacrylate (ACR) impact modifier with core-shell structure and Polyacrylate plasticizing processing aids were synthesized with acrylate monomers. And the copolymerization additives with high impact resistance and anti-bacterial properties were obtained by grafting acrylic monomers with CTS.In the research, impact modifier I-ACR with soft core hard shell structure was synthesized with butyl-acrylate (BA) and methyl-methacrylate (MMA) as the soft and hard monomers, KPS as initiators by seeded emulsion polymerization. Chitosan(CTS), as a kind of natural antibacterial agent, contains various functional groups and reaction activities, and can be oxidation, reduction, grafting and other reactions. Water-soluble CTS with the best performance was selected by comparing on the properties of kinds of CTS. Then the other ACR was synthesized by grafting MMA with CTS with CAN as an initiator. CTS-ACR with good antibacterial capability was synthesized by grafting acrylic monomers with CTS which is full of anti-bacterial properties. To determine the optimum reaction conditions and choose the easiest method of drying, the selection and quantities of the emulsifier and initiator of the two systems, the effect of the feed ratio of the soft and hard monomers and the temperature and time of the polymerization on the performance of ACR was examined with emulsion solid content, gel rate, the monomer conversion ratio and the mechanical properties of PVC modified by ACR as indexes. The structure of the polymer was inspected by IR and the glass-transition temperatures were measured by DSC. Particle size and distributing of emulsion were tested by laser particle apparatus in order to study the core-shell structure of ACR.With the intrinsic viscosity as the main indicator, ACR impact modifier with high molecular weight was also synthesized by emulsion polymerization. The preparation and performance test of processing aids ACR: ACR processing aids was synthesized with butyl-acrylate(BA) and methyl-methacrylate(MMA) as the monomers, KPS as initiators by emulsion polymerization. The relationship between the factors of the polymerization and the polymer molecular weight was investigated to obtain the following results to meet this system: (1)The more the emulsifier, the higher molecular weight of ACR in certain extent, but the excessive emulsifier will go against the increasing of the molecular weight of ACR; (2)Increasing the initiator concentration will decrease the molecular weight of ACR; (3)The lower temperature of the polymerization is beneficial to increase the molecular weight of ACR; (4)Extending the time of the polymerization will increase the molecular weight of ACR in the polymerization process condition improved; (5)As the feed capacity of BA is increasing, the molecular weight of ACR will be higher.Three kinds of polyacrylate polymers were mixed with PVC respectively to obtain the blends. The blending temperature and time were determined. The properties of PVC with different portions of ACR, such as impact strength, flexural strength, tensile strength, the stability of enduring heating were tested. The brittle and ductile fracture of the impact fracture surface of the PVC blending materials was examined according to observe the dispersion of particles of the blends sections by SEM. The two ACR impact modifiers can improve the impact resistance of PVC, and the ductility of PVC will be higher with the portions of ACR increasing. The mechanical property of the blends with I-ACR is superior to that with CTS-ACR. The rheological property of the blend materials with different portions of P-ACR was tested. P-ACR can be found in significant improvement in processing performance of PVC, and the more portions of P-ACR, the better processing performance of the blend materials.