Study On Interpenetrating Network (IPN) Structure Compounds By Seed Suspension Polymerization

PBA/PMMA and PBA/PS composite particles or PBA/PVC composite latex, wasprepared by seed suspension polymerization or seed emulsion polymerization with n-butylacrylate (nBA), methyl methacrylate (MMA), styrene (St) and vinyl chloride (VC) as rawmaterials and methyl acrylic acid allyl ester (AMA) as crosslinking agent. ACR-g-VCcomposite resin with high impact resistance performance was prepared with PBA/PVCemulsion particle grafted with VC.Microstructure, thermal stability, processing performance and impact resistance ofcomposites and blending material were characterized by Malvern particle size of instrument,scanning electron microscope (SEM), transmission electron microscope (TEM), dynamicthermal mechanical analyzer (DMA), element analysis, the torque rheometer, charpyimpact instrument and thermo-gravimetric (TG).The research results demonstrated that coating degree of PBA/PMMA, PS/PBAcomposite particles synthesized by seed suspension polymerization depended on swellingtime and monomer weight ratio of the feeding monomer. PVP with higher molecular weightwas more effective to maintaining the polymerization stability, and the processingtemperature reduced, plasticizing performance improved with the core-shell ratio andswelling time increasing. Both PBA/PMMA and PBA/PS particles are beneficial toenhancing notched impact strength of PVC. Moreover, thermal decomposition temperaturesof the PVC increased with the increasing of the PBA/PS content.PBA/PVC blend modification system was extensively studied. The particle sizedistribution of PBA latex was similar to PBA/PVC latex, and particle size of PBA latexgrafted with PVC increased obviously. TEM photographs indicated the PBA/PVCcomposite particles had obvious core-shell structure. The emulsifier feeding method had noinfluence on particle size and impact strength of ACR/PVC blending materials. ACR/PVCblending materials showed excellent impact strength with low content of ACR. Ductilefracture can be seen on surface of SEM photographs. Impact results of blending of PVCand modifiers with different particle size indicted the optimal impact strength of PVC resinoccurred when emulsion particle size was around302nm.As the ACR-g-VC in situ modification system, polymerization rate and degrees of and demulsification or agglomerate increased with particle size reducing and content of ACRincreasing. Graft copolymer played an important role in improving compatibility, whichcaused the high and low transition temperature closed. The rubber content in the samplescould be determined by the element analysis method. With the rubber content increasing,the polymerization became unstable, the agglomerate content increased. Therefore, wecould not calculate the exact rubber content.