Toughening Modification SPS With PBA-aPS Core Shell Latex Particles

The subject using the pre-emulsification-semi-continuous seed emulsion polymerizationmethod for synthetic of core-shell structure butyl acrylate-polystyrene (PBA-aPS) latexparticles. And through the laser particle size analyzer, transmission electron microscope andFourier transform infrared spectrometer methods, it can characterize on the latex particle’saverage particle size, size distribution and morphology. Experiments inspected the emulsifier,initiator, temperature and pH factors to influence of the core-shell latex particle size and Stmonomer percent conversion. With the increase of the emulsifier the average particle sizedecreases; Along with the increase of the initiator and the pH value St conversion rateincreases; With the increase of temperature St conversion first increases and then decreases;The experimental results show: the obtained core-shell latex particles average particle size is170-180nm, core latex particle size is140nm, the distribution of particle size is very narrow.The PBA-aPS latex particles are indeed core-shell structure and aPS successfully wrapped inthe PBA core.Cross linking agent added to make the formation of highly cross-linked structure withinPBA-aPS latex particle’s core and shell, which limit the lipophilic polystyrene shell migrationto the particle internal. Because of using hunger feeding methods add the shell monomer, itcan make the particles production rate greatly improved.The synthesized PBA-aPS core-shell latex particles and syndiotactic polystyrene (sPS)were blended by twin screw extruder, the blends of sPS/PBA-aPS were tested and analyzedby HAAKE rheometer, differential scanning calorimeter (DSC), scanning electron microscope(SEM) and impact testing machine, use these methods analyze of structure morphology andproperties of sPS/PBA-aPS blends. The results showed that the compatibility of PBA-aPSlatex particles and sPS was better, Latex particles in the system of sPS distribution is uniform.Impact strength of sPS has been increased about1-fold with PBA-sPS latex particles added,and heat resistance also increase.