基于原位红外光谱的热固性酚醛树脂固化过程研究

采用原位红外光谱测试方法,通过对同一样品在连续变温过程中的红外谱图分析研究热固性酚醛树脂在固化过程中的化学结构变化和固化行为。结果表明:该热固性酚醛树脂的固化过程主要存在两种反应,羟甲基与酚环上的氢之间的取代反应、羟甲基与羟甲基间的缩合反应,且取代反应早于缩合反应发生。随红外曲线的实时变化可知,羟甲基的缩合反应过程中有醚键形成,而羰基的出现与醚键的消失有关。通过对酚醛固化过程中基团变化的连续实时监测,可为热固性酚醛树脂的固化工艺的确定提供科学依据。

Study on Curing Process of Thermosetting Phenolic Resin Based on In-Situ Infrared Spectroscopy

The chemical structure change and curing behavior of the same thermosetting phenolic resin sample during continuous heating process were studied by in-situ infrared spectroscopy. The results show that there are mainly two reactions during the curing process of the resin,substitution reactions of hydroxymethyl and active hydrogen on benzene ring, condensation reactions between hydroxyl methyl groups, and hydroxyl methyl preferentially reacts with ortho hydrogen on benzene ring. From the continuous changes of infrared spectroscopy curves, condensation reactions between hydroxyl methyl groups build ether bonds, while the occurrence of carbonyl is related to the disappearance of ether bonds.Through continuous real-time monitoring of phenolic group changes during curing process by in-situ infrared spectroscopy, a scientific basis can be provided for the curing procedures of thermosetting phenolic resin.