松香季戊四醇酯与甲基丙烯酸-2-羟乙酯反应研究

Study on Reaction of Rosin Pentaerythritol Ester and 2-Hydroxyethyl Methacrylate

松香季戊四醇酯(RPE)环上的共轭双键可以与甲基丙烯酸-2-羟乙酯(HEMA)发生Diels-Alder加成发应,同时松香季戊四醇酯仍有一定酸值,其中未反应的羧基可与HEMA进行酯化反应。研究了反应温度和物料配比对RPE与HEMA反应的影响,对产物进行了红外和热重分析。结果表明:在一定的物料比下,反应温度升高,加成反应和酯化反应速度加快,反应温度提高更有利于酯化反应的进行;在一定的反应温度下,HEMA的物质的量增加,产物的酸值到一定程度不再下降,而溴值持续下降,表明有利于HEMA与RPE的加成反应。红外光谱表明将HEMA接到了RPE的分子结构上,热重分析表明产物的初始分解温度和最终分解温度有所下降。

Rosin pentaerythritol ester（RPE） has some carboxyl groups and conjugate double bonds in its molecular structure, so it can react with 2 -hydroxyethyl methacrylate （HEMA）, which has hydroxyl group and double bonds, by esterification and Diels -Alder addition reaction. The effects of reaction temperature and molar ratio on the reaction were investigated. The structure of the product was characterized by IR and the thermal stability was tested by thermo - gravimetry （TG）. The results show that as the temperature rising, the esterification and addition rates increase at fixed ratio of RPE to HEMA, it favors the esterification. As the molar ratio of HEMA increases, the bromine value is decreasing continuously, but the acid value stops dropping to some degree, this indicates that the molar ratio of HEMA favors the addition reaction. The IR spectrum shows that RPE has reacted with HEMA and the TG curve indicates that the initial and final decompose temperatures drop slightly.