接枝改性剂SBR-g-MS的组成结构设计与透明ABS树脂的性能研究

Composition and Structure Design of Graft Modifier SBR-g-MS and Performance Exploration of Transparent ABS Resin

采用乳液聚合技术制备粒径为80 nm的丁苯胶乳(SBR),以醋酸为附聚剂,将SBR附聚至300 nm左右,采用种子乳液聚合技术在SBR乳胶粒子上先后接枝共聚苯乙烯(St)和甲基丙烯酸甲酯(MMA),合成SBR质量分数为60%的SBR-g-MS接枝共聚物。将其与聚甲基丙烯酸甲酯(PMMA)和苯乙烯-丙烯腈共聚物(SAN)熔融共混制备透明丙烯腈/丁二烯/苯乙烯(ABS)树脂,研究了SBR-g-MS接枝共聚物组成结构与PMMA/SAN共混比例对透明ABS树脂性能的影响。结果表明,将基体树脂折光指数与SBR乳胶粒子折光指数匹配可以获得透光性能优良的ABS树脂;当SBR中丁二烯(Bd)与苯乙烯的比例为70/30(质量比,下同)时,其和PMMA与SAN的比例为44/56的基体树脂共混后所得ABS树脂具有最佳透光效果;Bd与St的比例为75/25、PMMA与SAN的比例为48/52时,Bd与St的比例为80/20时、PMMA与SAN的比例为53/47时,透明ABS树脂透光效果最佳;透光率均在85%以上;SBR-g-MS接枝共聚物中接枝共聚单体St含量过高会显著降低ABS树脂光学性能,接枝共聚单体St与MMA比例为25/75时,ABS树脂光学性能最佳,透光率86.46%;SBR-g-MS接枝共聚物与基体树脂共混比例增加,ABS树脂的冲击强度呈上升趋势,透光率在SBR含量大于15%(质量分数)时骤然下降.胶含量在15%时透明ABS树脂的冲击强度为158.7 J/m,透光率86.46%。

Styrene-butadiene latex(SBR)with a particle size of 80 nm was prepared by emulsion polymerization,and acetic acid was used as agglomerating agent to agglomerate SBR to about 300 nm.The SBR-g-MS graft copolymer with 60%SBR was synthesized by grafting styrene(St)and methyl methacrylate(MMA)by seed emulsion polymerization.It was melt blended with polymethyl methacrylate(PMMA)and styrene-acrylonitrile copolymer(SAN)to prepare the transparent ABS resin.The effects of the composition and structure of the SBR-g-MS graft copolymer and the blending ratio of PMMA/SAN on the properties of the transparent ABS resin were studied.The results showed that matching the refractive index of the matrix resin and the SBR latex particles can help to obtain the ABS resin with excellent transmittance.When the mass ratio of butadiene(Bd)to styrene in SBR was 70/30,the ABS resin with m(PMMA)/m(SAN)was 44/56 had the best transmittance;when m(Bd)/m(St)was 75/25,m(PMMA)/m(SAN)was 48/52,m(Bd)/m(St)was 80/20,m(PMMA)/m(SAN)was 53/47,the ABS resin has the best transmittance,the transmittance was above 85%.Furthermore,when the ratio of grafting comonomer St to MMA was 25/75,the optical performance of ABS resin was the best and the transmittance was 86.46%.As the blending ratio of SBR-g-MS graft copolymer and matrix resin increased,the impact strength of ABS resin increased,and the transmittance dropped suddenly when the rubber content was more than 15%.When the rubber content was 15%,the impact strength of the transparent ABS resin was 158.7 J/m,and the transmittance was 86.46%.