纳米氧化锌催化合成松香甘油酯的研究

首次采用纳米粒子氧化锌作为松香与甘油酯化反应的催化剂,实验讨论了催化剂、反应温度、反应时间和醇酸比对反应工艺的影响,并在此基础上进行正交试验,得出反应的最佳工艺条件为:在氮气的保护下,用松香与过量20%质量分数的甘油酯化反应的反应温度为250°C、反应时间5h、催化剂0.25%(以松香量为基准)、甘油与松香的质量比为:12.19∶100。在最佳工艺条件下,进行了稳定性实验,得到的松香甘油酯的酸值为:7.3,软化点:86.9°C,产率为94.5%,色泽:加纳色级8,在苯中溶解度(1∶1):清,符合136#松香甘油酯质量指标。纳米氧化锌催化松香酯化相对目前工业常用的ZnO催化剂而言,缩短了反应时间、降低了反应温度,有应用价值。

Study on Synthesis of Rosin Glycerine Ester with Nanometer Zinc Oxide Catalyst

The nanometer sized zinc oxide was used as catalyst for esterification of rosin with glycerine. The influence of reaction temperature, time catalyst quantity and the ratio of glycerol and rosin on the reaction was studied. The optimum reaction conditions obtained by orthogonal test are: temperature and time, 250(°C) and 5 h respectively; catalyst quantity 0.25%(based on rosin weight); the ratio of glycerol to rosin, 12.19∶100(glycerol is 20% in excess of the theoretical quantity). Under the optimal conditions, the acid value of the rosin glycerine ester prepared was 7.3, the softening point was 86.9(°C), the yield was 94.5%, the color level was 8(Gardner). The product was clear in benzene, and it satisfied the quality standard of 136~# rosin glycerin ester. Compared to conventional ZnO catalyst that used in industry, the nanometer catalyst was better. The reaction time was shortened, the reaction temperature reduced, and the dosage of catalyst also reduced.