甲基丙烯酸甲酯改性聚醚聚氨酯的结构形态与力学性能

采用同步法合成了聚氨酯(PU)/聚甲基丙烯酸甲酯(PMMA)的线型共混物、嵌段共聚物和互穿高聚物(IPN)。凭藉力学性能测试、电镜观察和动态力学谱分析,研究了光固化、热固化、化学组成、物理结构等因素对体系力学性能、结构形态和粘弹行为的影响。结果表明:PU/PMMA是呈两相结构的部分相容体系,其中线型共混物伸长率最大,IPN强度最高,而嵌段共聚物的力学性能较差。此外,嵌段共聚物和IPN光固化体系形成的相畴结构均一,其抗张强度和伸长率明显高于热固化体系。聚合物的力学性能除了受化学结构影响以外,还与化学组成有关,随体系中PMMA含量和PU中硬链段含量增加,聚合物抗张强度升高,伸长率下降。

Morphological Structure and Mechanical Properties of Polyurethane Modified by Methyl Methacrylate

Three kinds of PU/PMMA i.e., Linear polymer, block copolymer and interpenetrating polymer network (IPN), were synthesized by the simultaneous polymerization process respectively. The effects of factor such as photo-setting, heat-setting, chemical composition and physical structure on morphological structure and mechanical properties of polymers were studied with scanning electron microscopy, dynamic mechanical loss spectrum and mechanical tests. The results are as follows: PU/PMMA is a partly compatible system with two phase structure. Among them, the linear polymer has the highest elongation at break, IPN shows the strongest tensile strength while the block copolymer has poor mechanical properties. In addition, photo-set block copolymer and IPN system, with regular microphase domain structure, have higher tensile strength and elongation at break than those of heat-set polymers. As the contents of PMMA and hard segment in PU increase in the system, the tensile strength increases while the elongation at break descends.