不同硬段含量脂肪族聚脲的结构与性能研究

通过端氨基聚醚、异佛尔酮二异氰酸酯和异佛尔酮二胺反应 ,合成了一系列不同硬段含量的脂肪族聚脲 ,并用DSC和FTIR等考察了硬段含量对聚脲的微观结构与力学性能的影响 .研究结果表明 ,聚脲呈现部分微观分相的形态 ,随硬段含量增加 ,聚脲中软段和硬段间的相容性提高 ,脲羰基的氢键化程度增加 ,但软段的玻璃化转变温度变化不大 ;此外 ,材料的拉伸强度、撕裂强度和硬度等也随着硬段含量的增加而显著提高 .

MORPHOLOGY AND MECHANICAL PROPERTIES OF ALIPHATIC POLYUREA WITH DIFFERENT HARD SEGMENT CONTENTS

A series of aliphatic polyureas with different hard segment contents were synthesized by the reaction of isophorone diisocyanate with Jeffamine D2000 and isophorone diamine as chain extender in solution.The effect of hard segment contents on the morphology and mechanical properties for these polyureas was studied by using DSC and FTIR etc.The experimental results showed that the polyureas exhibited a partial phase separated morphology.The polyurea with higher hard segment contents showed a better compatibility between the soft and hard segments,and a higher degree of hydrogen bonding for the urea carbonyl groups existed in the system,but the values of T g for the soft segment regions almost did not depend on the hard segment content.The tensile strength,hardness and shear strength of polyurea specimens were enhanced greatly with increasing the hard segment content.