The Synthesis And Application Of Multi-layer Structure Of Core-shell MBS Particles

The methyl methacrylate-butadiene-styrene (MBS) copolymers with different structure were achieved by emulsion polymerization method. This paper studied the variation of core-shell structural particles MBS and their toughening behavior in poly (vinyl chloride)(PVC) matrix. By changing the monomer addition methods and the types of initiator, four different kinds of MBS were designed and synthesized with the same chemical composition, similar particle size and different particle structure:MBS with the structure of many small size sub-inclusions in the core which called "salami"; MBS with some larger volume sub-inclusions in it which called "micro-domains"; the typical double-layer structure of MBS was called "core-shell"; MBS with "hard/soft/hard" structure was called "multi-layer". By transmission electron microscope (TEM), it can be seen that four kinds of modifier MBS can be dispersed in PVC matrix well. By dynamic mechanics analysis (DMA), with the increase of rubber particle volume fraction of rubber, the rubber phase of the glass transition temperature (Tg) and internal friction peak (tanδ)max are higher. In terms of mechanical properties, with the "multi-layer" of the blend compared with the other three, has a higher impact strength and lower brittle-ductile transition temperature, and its yield strength and elongation is the highest. According to the different blends, it can be seen that the deformation zone can be obtained, even if MBS modifier particles structure has changed. The mechanism of the toughening PVC by cavitation cause shear yield PVC matrix, different forms of the cavitation:the first two MBS have cavitation in the rubber particle and rubber particle was debonding from the matrix (PVC), while the latter two MBS have cavitation inside the rubber particles only.This paper also studied the MBS with small particle size toughening behavior in PVC matrix. Three kinds of core-shell modifier MBS particles were synthesized by seed emulsion polymerization method, and the particle size ranged from 100 to 150 nm. By transmission electron microscopy, it can be observed that all MBS modifiers can disperse in PVC matrix well. By studying the mechanical properties of PVC/MBS blends, it can be concluded that the MBS with small particle size can also toughening PVC matrix effectively. For the deformation area, they can be toughened by cavitation in the rubber particles.