改性脲醛树脂合成工艺与性能的关系

比较了不同工艺、参数条件下合成改性脲醛树脂性能指标的变化趋势,以及不同工艺参数对改性树脂胶合性能的影响。结果表明:加成反应阶段,pH的降低对改性脲醛树脂各项性能的提高有利;升高反应温度可以改善改性脲醛树脂的综合性能,适中的加成反应时间有助于改性脲醛树脂的各项性能的改善;缩聚反应阶段,pH的降低不利于储存期的延长,但对改性脲醛树脂其他性能的提高均有较好影响,缩聚反应的温度过高或过低均不利于改性脲醛树脂综合性能的提高;初摩尔比明显地影响储存期,初摩尔比高则储存期长;甲醛释放量随初摩尔比降低呈升高趋势。

The Relationship Between Synthetical Technics and Performance Target of Modified UF Resin Adhesive

The experiment compares variational direction of performance target with different synthetical technics of modified UF resin,and the effects of different synthetical technics on agglutination performance.According to results of experiment, the reduced pH value of additive reaction can be propitious to performance target of modified UF resin.The increased temperature of additive reaction can improve general performance of modified UF resin, it is the same as the medium time of additive reaction.The decreased pH value of polycondensation reactions have good effects on performance target of modified UF resin except storage life.Higher or lower temperature of polycondensation reaction has no advantage of allround properties.The changes of initial molar ratio can affect storage life clearly,the higher initial molar ratio the longer storage life.Formaldehyde emission increases as initial molar ratio reduces.