不同催化剂对松香季戊四醇酯合成的影响

Different catalyst effects in synthesis of rosin pentaerythritol ester

针对目前制备松香季戊四醇酯的催化剂毒性较强或成本昂贵,且所需能耗大等问题,本文以高效、无毒、绿色环保、廉价的羧酸盐和碱性盐类化合物为催化剂催化松香和季戊四醇酯化反应合成松香季戊四醇酯,考察了催化剂种类和用量、n(松香)∶n(季戊四醇)、反应时间和反应温度等因素对酯化反应的影响,得出较佳的反应条件,即n(松香)∶n(季戊四醇)为1∶0.25、松香30.0g、催化剂硬脂酸锌为松香质量的0.20%、反应时间7h、反应温度250℃。在上述条件下,所得产物松香季戊四醇酯的酸值为18.07mg/g、软化点为94.7℃、色泽为9~10(铁钴法)。同传统催化剂氧化锌相比,在不使用其他助剂的情况下,所得产物色泽浅、软化点和酸值较低,且反应具有催化剂用量少、反应温度低、无需分离催化剂等优点。

The catalysts for making pentaerythritol ester of rosin have some drawbacks, such as strong toxicity and high costs. To solve such problems, a new type of catalyst was proposed to produce rosin pentaerythritol ester in this paper. Using the efficient, nontoxic, environment-friendly and cheap carboxylic acid salts and alkali salts as catalysts, the pentaerythritol ester of rosin was synthesized, and the effects of the variety of catalyst, catalyst amount, n（rosin）∶n（pentaerythritol）, reaction time, and reaction temperature on the catalytic performances were investigated. It was found that zinc stearate was an efficient catalyst for the reaction, and the optimum reaction conditions were obtained as follows： n（rosin）∶n（pentaerythritol） is 1∶0.25, rosin 30.0 g, zinc stearate 0.06 g, reaction time 7 h and reaction temperature 250℃. Under those reaction conditions, the acid value of rosin pentaerythritol ester reached 18.07 mg/g, and the melting point and the color of the product was 94.7℃ and 9—10（Fe-Co scale）, respectively. Compared with the traditional catalyst zinc oxide, the obtained product had some advantages such as lighter color, lower softening point and acid value, less catalyst, and lower reaction temperature.