以过氧化苯二甲酰为自由基引发剂,甲苯为溶剂,研究了聚马来酸酐(PMA)最佳合成条件,即引发剂质量分数10%,反应温度95℃,反应时间6 h。通过对聚合残液的MS分析,聚合残液主要成分为马来酸酐(MA),通过聚合残液的酸值分析,得到MA的利用率为63.5%。针对MA利用率较低,将聚合残液循环利用。循环结果表明,经5次循环使用,MA的累计利用率可达90.3%,并随着循环次数增多,MA的累计利用率逐步增大。所合成聚马来酸酐经FTIR1、HNMR分析,结构正确;凝胶渗透色谱(GPC)分析,每次循环产品PMA的平均相对分子质量变化不大,平均相对分子质量Mn保持在930~940,相对分子质量分布系数为1.12。 The optimum synthesis conditions of polymaleic anhydride (PMA) were studied with phthaloyl peroxide as free radical initiator and toluene as solvent, that is, the initiator mass fraction was 10%, the reaction temperature was 95 ℃ and the reaction time was 6 h. Through the MS analysis of the polymerization residue, the main component of the polymerization residue was maleic anhydride (MA). The acid utilization of the polymerization residue was 63.5%. For MA utilization is low, the polymerization residue recycling. The results of the cycle show that after 5 cycles, the cumulative utilization rate of MA can reach 90.3%. As the number of cycles increases, the cumulative utilization rate of MA gradually increases. The structure of polymaleic anhydride synthesized by FTIR1 and HNMR was correct. The gel permeation chromatography (GPC) showed that the average relative molecular mass of PMA per cycle did not change much, and the average relative molecular mass Mn remained at 930-940. Molecular weight distribution coefficient of 1.12.