苯乙烯—甲基丙烯酸共聚物的合成及表征

The Synthesis and Characterization of Poly(styrene-methacrylic acid) Copolymer

采用简单、经济、稳定的悬浮聚合法合成了苯乙烯—甲基丙烯酸共聚物(SMAA),得率为92%左右.通过正交试验确定了最佳配方.经FT—IR、DSC、元素分析、化学滴定、GPC等测试方法表征,证实了所合成的产物为透明的苯乙烯—甲基丙烯酸无规共聚物.研究表明,SMAA的耐热性比PS好得多,其玻璃化温度随共聚物中MAA含量的增加而增大,SMAA20的Tg为138.8℃,比PS的约高40℃,在100℃时热拉伸强度保留率为72.3%.共聚物的加工性能良好,熔体指数为8.05g/10min(230℃,载荷50N),熔化特性良好.其力学性能比PS有明显提高,拉伸强度和弯曲强度分别比PS提高52.2%和43.6%.

Styrene-methacrylic acid (SMAA) copolymer was simply copolymerized by a stable and economic suspension method,with a yield of about 92%. The best formula was determined by orthorhombic experiment. By means of FT-IR,DSC,elementary analysis,chemical titration and GPC,it was proved that the product was a transparent random copolymer. It was also shown that the heat-resistance of SMAA was much better than that of PS,and the Tg of SMAA increased with the increase of the content of MAA in the copolymer. The Tg of SMAA20 was 138. 8℃,40℃ higher than that of PS;the retention ratio of heat tensile strength at 100℃ was 72. 3%. The processibility of the copolymer was good,and the melt index was 8. 05g/10min(at 230℃,loading 50N),with a good melt character. The mechanical properties of the copolymer were much better than those of PS,the tensile strength and bending strength were 52. 2% and 43. 6% higher than those of PS respectively.