Preparation Of New ASA Elastomer Particles And Toughening SAN Resins

ASA is the resin of PBA-g-SAN graft copolymer of styrene and acrylonitrile copolymer fused blends, it is a blend of three-component two-phase system, which is an impact modifierwith a good performance. In this experiment,we introduced rubber core of butadiene and styrene in traditional PBA core.Synthesis of p (BA-co-Bd-co-St)-g-SAN/SAN copolymer by emulsion polymerization method, blending with SAN resins, forming ASA/SAN blends. Mechanical properties and morphology of blends have been researched and the conclusion are as follows:(1) A series of ASA grafted copolymer were synthesis by changing the rubber particle size, and melt blending with SAN, and the ASA/SAN blends were gained. It was found that that impact strength of ASA/SAN blend increased and then decreased with rubber size increasing. The DMA curve shows that p (BA-co-Bd-co-St) three components in the latex is copolymerized.DSC analysis can be seen in the figure, p (BA-co-Bd-co-St)-g-SAN thermal stability better than PB-g-SAN.From the scanning electron microscope photographs can be seen, rubber particles of PBA-g-SAN graft copolymer have serious gathering, P(BA-co-Bd-co-St) elastomer particles is uniform dispersion in SAN matrix, thus giving the blends have good mechanical properties. We can see from the TEM photoes, when rubber particle size is too small, P(BA-co-Bd-co-St) elastomer particles occurs serious accumulation in the matrix, when the particle size is big enough, rubber particles uniform dispersed in a matrix.(2) A series of ASA grafted copolymer were synthesis with the latex of different ratio in core consititute, and blending with SAN resin forming ASA/SAN blends. It was found that as the PBA of rubber core ratio increasing, the impact strength of blends increased and then decreased. DMA and DSC results showed that with PB ratio increasing, glass transition temperature of blends is diminishing, thermal stability of blends gradually poor.