低相对分子质量苯乙烯-马来酸酐交替共聚物的合成

The synthesis of low-molecular-weight styrene-maleic anhydride alternating copolymer

将引发剂偶氮二异丁腈(AIBN)、共聚单体苯乙烯(St)和马来酸酐(MA)溶解于甲苯中,采用沉淀聚合法合成苯乙烯-马来酸酐共聚物(SMA).分别研究了反应温度、引发剂用量、反应时间、单体配比和单体浓度对聚合物得率和酸酐含量的影响.采用正交实验确定最优反应条件为:单体浓度20%,单体物质的量比为1∶1,引发剂用量为0.60%,反应温度为86℃,反应时间2h,产物得率为86.86%,酸酐含量为50.28%.并利用傅里叶变换红外光谱(FTIR)、核磁共振碳谱(^(13)C NMR)、凝胶渗透色谱(GPC)和热分析法分别研究聚合物的分子结构、相对分子质量及相对分子质量分布和热稳定性.结果表明产物是苯乙烯-马来酸酐交替共聚物,相对分子质量分布较窄,具有良好的热稳定性.

A styrene-maleic anhydride copolymer （SMA） was synthesized by solution-sediment polymerization method, with azobisisobutyronitrile （AIBN） as an initiator. The effect of polymerization temperature,dosage of initiator,reaction time, the ratio of styrene to maleic anhydride and the monomer mass fraction on polymerization was investigated in detail. Orthogonal experiments were used to determine optimal reaction conditions. The yield of the copolymer was 86.86 % with an anhydride content of 50. 28%, under the conditions of monomer mass fraction of 20%,a monomer molar ratio of 1 ： 1 ,initiator amount of 0.60% ,the reaction temperature and reaction time was 86 ℃ and 2 h,respectively. The structure of the copolymer, the molecular weight and molecular weight distribution and the thermal stability were investigated by using Fourier transform infrared spectroscopy （FTIR）, 13 C NMR spectroscopy, gel permeation chromatography （GPC） and thermal analysis, respectively. The SMA was confirmed to be the alternating copolymer with a narrow molecular weight distribution and well thermal stability.