Toughening Modification Of PVC With Acrylate Copolymer

PVC, as a widely used common resins with favorable properties, rank the second position in terms of the production, only behind the polyethylene. But, in the application of PVC, it also shows the defects of brittleness and poor thermal stability. Therefore, it's easy to fracture when impacted. Thus the modification of PVC has become an important field of its application research. In this paper, the acrylate resins (ACR) with core-shell structure, used as PVC toughening modifier, were studied. The effects of formulation and process parameters of preparation were discussed, on the basis of which, the optimum formulation and preparation technology for ACR were obtained. In this thesis, by using seeded emulsion polymerization, the acrylate copolymer latex with core-shell structure were synthesized, in which butyl acrylate (BA) is used as that main core monomer and methyl methacrylate(MMA) as the main shell monomer. From the toughening viewpoint, the crosslinking networks were established in the core layer, while the polymer in shell layer still keep linear. The impact test shows that PVC modified by the ACR prepared bears excellent impact-resistance.The latex particle diameter, glass-transition temperatures of ACR and fracture surfaces of PVC/ACR were studied by dynamic laser scattering, DSC and SEM, respectively. Mechanism of the toughening effects of ACR on PVC was also set forth. Combining with the mechanical properties tests, the effects of emulsifiers, monomers, crosslinking network, blending process of ACR and PVC and ACR contents on impact-resistance were investigated. Finally, the optimum conditions and formulations for preparing ACR and the blending technology of ACR and PVC were obtained. Comparing with ACR impact modifiers in home and outsides, ACR prepared in present work, isn't inferior to the renowned foreign ACR products at all, surely surpass the domestic products.