嵌段聚氨酯脲的形态与性能——软链段结构和分子量的影响

Morphology-Property Relationship of Segmented Polyurethaneurea——Influences of Soft Segment Structure and Molecular Weight

合成了不同软链段长度的聚醚型、聚酯型嵌段聚氨酯脲弹性体,以及聚醚-聚酯软链段聚氨酯脲弹性体(PUU)。借助SEM、DSC以及拉伸试验机分析其结构、形态对力学性能的影响。研究表明,相分离程度随软链段分子量的提高而提高。在软链段分子量相同时,聚醚为基础的PUU的相分离程度较聚酯为基础的PUU高。以聚醚-聚酯为软链段的PUU呈现了聚醚型和聚酯型PUU的各自形态,有较大的相区尺寸和较明显的相界面。力学性能数据证实了形态研究的结果。

The relations of the morphology and property of several series of segmented PUU were studied in film form by using SME, DSC and tensile stress-strain data. The polyether-based and polyester-based PUU block copolymers were synthesized by using PPO-EO polyether or PBA polyester with different molecular weights, MDI and DETDA. Especially, the polyether-ester-based PUU were synthesized. The extent of phase separation inscreases with increasing molecular weight of soft segment. The polyether-based PUU shows the better phase separation than polyester-based with the same molecular weight of soft segment. The polyether-ester-based PUU shows the morphology of both polyether-based and polyesterbased PUU and with larger domain size and interface.