核-壳聚丙烯酸酯胶粉合成及其增韧SAN树脂应用研究

Study on Preparation and Promoted Features of Core-Shell Acrylate Particles for SAN Resin Toughening

以丙烯酸丁酯(BA)、苯乙烯(St)、甲基丙烯酸甲酯(MMA)等单体为原料,通过半连续种子法成功合成核-壳聚丙烯酸酯乳液,研究合成工艺对乳液性能及其破乳产物胶粉增韧苯乙烯-丙烯腈共聚物(SAN)树脂性能的影响。结果表明:乳液合成过程中当核(BA)∶壳(St、MMA)的质量比为50∶50,乳化剂用量为总单体量1.5%,K12∶AEO9质量比为1.4∶0.1,添加0.6%过硫酸铵(APS)引发剂、0.3%二甲基丙烯酸乙二醇酯(EGDMA)交联剂、0.2%pH缓冲剂,可以获得破乳效果好的核-壳聚丙烯酸酯乳液,且破乳收率高达97.6%。最佳工艺条件下所得破乳胶粒中EGDMA与BA单体成功以C-C化学键交联,且乳液粒子中主链完整保存。破乳胶粉与SAN树脂以相同质量共混改性后SAN缺口冲击强度达到最高值(6.0 kJ/m^(2))。通过增加胶粉的比例可以有效提高对SAN树脂的增韧效果。

The core-shell polyacrylate emulsion was successfully synthesized by semi-continuous seed method with butyl acrylate(BA),styrene(St),methyl methacrylate(MMA)and other monomers as raw materials.The effects of synthesis process on the properties of emulsion and the properties of styrene-acrylonitrile copolymer(SAN)resin toughened by latex powder were studied.The results showed that when the mass ratio of core(BA)to shell(St,MMA)is 50∶50,the amount of emulsifier is 1.5% of the total monomer amount,and the mass ratio of K12 to AEO9 is 1.4∶0.1,adding 0.6% ammonium persulfate(APS)initiator,0.3% ethylene glycol dimethacrylate(EGDMA)crosslinking agent,0.2% pH buffer,the core-shell polyacrylate emulsion with good demulsification effect can be obtained,and the demulsification yield is as high as 97.6%.Under the optimal process conditions,EGDMA and BA monomers in demulsification particles are successfully cross-linked by C—C chemical bonds,and the main chain in the emulsion particles is completely preserved.The SAN notch impact strength reaches the highest value(6.0 kJ/m^(2))after the demulsifier powder is blended with the SAN resin with the same mass.The toughening effect on SAN resin can be effectively improved by increasing the proportion of latex powder.