| All-acrylic (ACR) equipped with a core phase of PBA and a shell phase of PMMA always plays a role of toughening modifier for PVC. The alloy of PVC/ACR exhibits some other excellent properties comparing with other alloys, such as high weather resistance, wide processing temperature and high thermal stability. Thus, the study was focused on the synthesis of ACR with high toughening effect and toughening efficient in order to reduce the cost.In this paper, coagulation PBA particles and traditional PBA particles were synthesized by one-step batch emulsion polymerization and seeded emulsion polymerization, respectively. And they were used as core phase of ACR. The influence of two structures of ACR on the properties of PVC/ACR blend were discussed, furthermore, the toughening mechanism of coagulation particles was analyzed. Moreover, the study of the effect of core-shell ratio and particle size of ACR on the properties of PVC/ACR blend were made.The results showed that the coagulation particles have a higher toughening effect and toughening efficient, and the binding force is weaker than traditional particles. The rubber content is the main influencing factor for toughening when the rubber content is less than5%, however, the dispersion state of rubber become the primary parameter to dominate the toughness when it reached to 7%, the ACR have the best properties when core-shell ratio is 70/30. The toughening effect is loosen when particle size is above 430.5nm, and the alloy of PVC/ACR exhibit the most excellent properties when the particle size of ACR is 226.3nm. Shear yielding of the matrix that induced by cavitation is the toughening mechanism in this system, and the coagulation particles are easier to cause cavitation to a certain extent as a result of the decrease of surface energy, because of the weak blinding force between the interface of the primary particle in a final particle. This is why the coagulation particle has a higher toughening effect. |
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