聚酯官能度对聚氨酯合成反应的影响

The Effect of Polyester Functional Degree on the Synthesis of Polyurethane

聚氨酯高分子的分子量及分子量分布对其物性影响很大。在线性聚氨酯溶液合成过程中,由于原料聚酯二元醇的端基残留羧基,不参与聚氨酯链增长反应,使其分子量达不到设计要求。研究了聚氨酯合成过程中,通过添加三官能度多元醇,通过理论计算的方法,调整聚酯原料在一定酸值时,其羟基组分各原料的羟基平均官能度达到2,并通过实验及生产合成验证了此方法具有明显的实用效果,用于聚氨酯树脂的合成,可获得设计物性的产品。

The molecular weight and its distribution of polyurethane polymer influence the physical property of polyurethaneto a great extent. In the process of synthesizing linear polyurethane solution,owing to the rudimental terminal carboxyl groupof polyesterglycol without participation in chain propagation reaction,the molecular weight of polyurethane does not come upto the design requirement. This article studied the method of improving polyurethane molecular weight in order to obtaining theproduction of desired physical property. Through adding trifunctional polylol,theoretical arithmetic,and adjusting acid valueof polyesterglycol toa certain value,the average functionality of every hydroxyl group raw material can reach two milligrampotassium hydrate per gram,which guaranted the chain propagation of polyurethane polymer. Experiment and manufacture allproved the obvious practical effect of the method.