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利用pH值的测定和凝胶转化率的计算,研究了醋酸甘油酯(三醋酸甘油酯、二醋酸甘油酯、一醋酸甘油酯)对甲阶酚醛树脂交联反应的催化作用,以及体系pH值对催化作用的影响。结果表明:在同样条件下催化速度:三醋酸甘油酯>二醋酸甘油酯>一醋酸甘油酯。体系的pH值对催化作用有重要的影响,pH值>12.5时交联反应不能进行,pH值越低,交联反应的速度越快;pH值对一醋酸甘油酯的催化作用影响最大,二醋酸甘油酯次之,三醋酸甘油酯最小。增加醋酸甘油酯的浓度和升高反应温度使交联反应的速度加快。
Using the determination of pH value and gel conversion rate, the catalysis of glycerol triacetate (glycerol triacetate, glyceryl diacetate, glyceryl monacetate) on the cross-linking reaction of resole resin was studied. Effect on catalysis. The results showed that under the same conditions, the catalytic rate was: triacetin> glyceryl diacetate> monoacetin. The pH value of the system has an important influence on the catalysis. The cross-linking reaction can not be carried out at the pH> 12.5. The lower the pH value is, the faster the cross-linking reaction is. The pH value has the greatest effect on the catalysis of glycerol monoacetate. Glycerol followed, the smallest triacetin. Increase the concentration of glycerol acetate and raise the reaction temperature to speed up the cross-linking reaction.