橡胶粒子大小及其协同作用对ASA增韧SAN树脂的影响

Effect of Rubber Particle Size and Its Synergism on ASA Toughened SAN Resin

在树脂增韧过程中,橡胶粒子通常起吸收应力、诱发银纹等作用,而橡胶粒子的尺寸对增韧效果有重要影响。通过种子乳液聚合制备不同尺寸的聚丙烯酸丁酯(PBA),并以PBA为基础制备不同大小的丙烯腈-苯乙烯-丙烯酸酯(ASA)接枝聚合物,再将ASA接枝聚合物与苯乙烯-丙烯腈共聚物(SAN)树脂熔融共混制得ASA/SAN共混物。通过红外光谱仪证明成功合成ASA接枝聚合物。考察单一粒子和大小粒子协同作用时ASA接枝聚合物对SAN树脂的增韧影响。结果表明:在单一粒子增韧SAN树脂时,PBA粒径为398.7 nm时,SAN/ASA共混物冲击性能最高达到360.6 J/m,此时屈服强度最低。将小粒子PBA(粒径98.5 nm)、大粒子PBA(粒径602.9 nm)在70/30配比下制备的ASA接枝聚合物与SAN树脂共混,冲击性能最高达到603.7 J/m,且具有较好的断裂伸长率。大小粒子配比的改变影响SAN/ASA共混物的(tanδ)max,在50/50配比下SAN/ASA储能模量明显上升,此时大小粒子表现出良好的协同作用。

In the process of resin toughening,rubber particles usually play a role in absorbing stress and inducing crazing,and the size of rubber particles has an important influence on the toughening effect.Poly(butyl acrylate)(PBA)with different sizes was prepared by seed lotion polymerization.Based on PBA,acrylonitrile-styrene-acrylate(ASA)grafted polymers with different sizes were prepared.ASA/SAN blends were prepared by melt blending of ASA grafted polymers and styrene-acrylonitrile copolymer(SAN)resin.The successful synthesis of ASA grafted polymer was proved by infrared spectrometer.The toughening effect of ASA grafted polymer on SAN resin was investigated under single particle and the synergistic effect of large and small particles.The results show that when the particle size of PBA is 398.7 nm,the impact strength of SAN/ASA blend reaches 360.6 J/m,and the yield strength is the lowest.The ASA graft polymer prepared by small particle PBA(particle size 98.5 nm)and large particle PBA(particle size 602.9 nm)at a ratio of 70/30 is blended with SAN resin,and the impact performance is up to 603.7 J/m,and it has good elongation at break.The(tanδ)max of SAN/ASA blends is affected by the ratio of large and small particles.The storage modulus of SAN/ASA blend increase significantly at the ratio of 50/50,and the large and small particles showes good synergistic effect.