副产物对醇酸缩聚反应动力学参数的影响

Effect of by-product on kinetics parameters of hydroxyl acid polycondensation

采用熔融缩聚法将新戊二醇／顺丁烯二酸酐或新戊二醇／邻苯二甲酸酐在150-180℃下反应。分析了反应过程中酸浓度和副产物水的变化,以及水对反应动力学参数的影响。结果表明,在计算动力学参数时,应采用体积摩尔浓度为单位,与采用质量摩尔浓度为单位相比,其参数值较大,并且不能忽略副产物的影响,否则将产生误差,并且误差的大小随反应温度的升高而增大,最大可达到23％左右。

Neopentyl glycol/maleic anhydride and neopentyl glycol/phthalic anhydride were reacted at 150 - 180℃ via melt polycondensation. The changes of acid concentration and water by-product were analyzed during the reaction process, as was the effect of water on kinetics parameters. The results showed that the volume molar concentration should be used as the unit for kinetics parameters calculation ;the kinetics parameters calculated using volume molar concentration as the unit were higher than those calculated using mass molar concentration as the unit; the effect of by-product should be taken into consideration to avoid error; and the error was increased and maximized about 23% with the increase of reaction temperature.