减压条件下催化酯化合成聚乙二醇单甲醚丙烯酸酯

聚乙二醇单甲醚丙烯酸酯是合成梳形分散剂的重要单体。以聚乙二醇单甲醚和丙烯酸为原料，对甲苯磺酸为催化剂，减压条件下直接酯化合成聚乙二醇单甲醚丙烯酸酯，采用傅立叶红外光谱表征产物结构。对反应条件进行了优化，结果表明，在温度90 ℃、压力0.06 MPa、催化剂用量为反应物总质量的2.0%、阻聚剂用量为丙烯酸质量的1.5%、丙烯酸与聚乙二醇单甲醚物质的量比3∶1和反应时间5 h条件下，酯化率可达92.6%。高效液相色谱分析证明，用饱和食盐水和乙酸乙酯萃取后的产物纯度为99.2%。

Synthesis of polyethylene glycol monomethyl ether acrylate by esterification under vacuum condition

Polyethylene glycol monomethyl ether acrylate(MPEGAA) was the important monomer for synthesis of comb dispersant.Using p-toluene sulphonic acid as the catalyst,MPEGAA was synthezied by the esterification of polyethylene glycol monomethyl ether(MPEG400) and acrylic acid under vacuum.The structure of the product was characterized by Fourier transform infrared spectroscopy.The results showed that the esterification rate of 92.6% was attained under the optimum reaction condition as follows:reaction temperature 90 ℃,reaction pressure 0.06 MPa, catalyst dosage 2.0% of total mass of the reactants,inhibitor amount 1.5% of acrylic acid mass,molar ratio of acrylic acid to MPEG400=3∶1 and reaction time 5 h.The results of HPLC analysis indicated that the purity of the product extracted with saturated brine and ethyl acetate was 99.2%.