一元胺为扩链剂合成聚氨酯的研究

THE STUDY OF SYNTHESIS OF POLYURETHANE BY EXTENDING CHAIN OF MONOACIDIC AMINE

采用一元胺为扩链剂和逐步减少扩链剂用量的方法合成了一系列聚氨酯样品，发现随着扩链剂用量的减少，断裂伸长率和拉伸强度都有显著的增加，当聚四氢呋喃二元醇分子量是１６８４，正戊胺是理论量的一半时，断裂伸长率和拉伸强度分别达到１９９０％和１０４Ｎ／ｃｍ２，这是用传统的合成方法所达不到的［１～３］＼．小角激光光散射的结果显示本文合成的样品为亚微观无定形结构。

In this article, monoacidic amine is used as chain extender, the change of extensibility of PU with reducing the amount of chain extender is investigated. If the amount of extender is reduced, the excessive NCO groups can react with the hydrogen atoms in NHCOO ; and form branch chain; the structure of macromolecular chain is changed greatly; these reaction let the hard segment more collect along the macromolecular chain, the effect of the cross bridegion of crystallizing microregion of hard segment is even more against stretch, so ultimate strength and elongation are improved greatly. When the molecular weigth of PTMG is 1684 and n amylamine as the extender, the ultimate strength and elongation are 10 4 N/cm 2 and 1990%; M.W. of PTMG is 1073 and n octyl amine as the extender, the ultimate strength and elongation are 1.28×10 4 N/cm 2 and 1635% respectively. The submicroscopic structure of the samples is found to be amorphous by the method of Small Angle Laser Light Scattering.