The Study On Structure And Properties Of Acrylate Rubber

The saturated main chains and the side ester groups lead to acrylate rubber(ACM) having good high temperature resistance and oil resistance, which is widely used in the automotive industry. AR71 and AR72 LS have a large shares in the market。In this paper, GPC, FTIR, NMR and other analytical instruments were used to study the molecular structure and properties of AR71 and AR72 LS with soap-sulfur curing system. Then AR71 and other four kinds of homemade acrylate rubbers were compared and studied. Acrylate rubber and polylactic acid(PLA) have certain foaming properties. At last, with acrylate rubber and Polylactic acid(PLA) blends as the matrix, and azodicarbonamide(AC) as the foaming agent, the EVM/PLA foamed materials were prepared by molding. Effect of filling coefficient and contents of Ca CO3 on the ACM/PLA foamed materials were studied. Besides that the shape memory properties of foamed materials were explored.The results showed that the number average molecular weight of AR71 was 274,982 and the molecular weight distribution was 3.349, that the glass transition temperature was-15 ℃, that ethyl acrylate was the monomer of AR71 and chlorine ethyl vinyl ether was used as vulcanization monomer. With the increasing contents of carbon black, mooney viscosity increased significantly and Payne effect became clear; the torque and degree of crosslinking increased; hardness and modulus of vulcanized rubber increased gradually as well; but the tensile strength and elongation at break declined. Consideration of mechanical properties and aging resistance, filling 30 phr carbon black for AR71 is the best amount.The number average molecular weight of AR72 LS was 274,667 and its molecular weight distribution was 4.459. The glass transition temperature of AR72 LS was-28.9℃. Ethyl acrylate, butyl acrylate and methyl methacrylate were the monomers of AR72 LS and vulcanization monomer was chloroethyl vinyl ether. With the increasing contents of carbon black, Mooney viscosity, tensile strength, hardness and modulus of vulcanized rubber increased gradually, however, the elongation at break increased at first and then declined. Consideration of mechanical properties and aging resistance, filling 50 phr carbon black for AR72 LS is the best amount.Compared with the four kinds of ACM, the number average molecular weight of AR71 was the biggest and molecular weight distribution was the narrowest. In addition, Mooney viscosity of raw rubber was higher. When filling50 phr N330, Payne effect of AR71 was most significant, which indicated carbon black dispersed worst. With soap-sulfur as curing agent, the curing degree of AR71 was highest and the mechanical properties and aging resistance were slightly worse.ACM/PLA blends were not suitable for atmospheric pressure molding method. When used high pressure molding method and filling coefficient beening 1.26, the foam’s density was relatively small and surface was smooth. With the increase of Ca CO3, porosity and expansion ratio decreased and cell density increased. Compression stress-strain curves of foams could be divided into 3 parts: linear elastic region, cell collapse and densification platform area. Energy absorption efficiency-stress curves and the ideal parameters- stress curves showed a peak at lower stress. In addition, ACM/PLA blend foams have a certain shape memory properties, which the fixed rate of shape under the experimental conditions was up to 99.86 %, and recovery rate of shape was 68.93 % and the maximum shape recovery rate was 8.33%/min.