脂肪族形状记忆聚氨酯的合成及表征

Synthesis and Characterizations of Aliphatic Shape Memory Polyurethanes

以脂肪族异氰酸酯HD I为硬段原料合成了脂肪族的形状记忆聚氨酯,通过调节硬段含量研究了硬段结构对形状记忆性能的影响。DSC、DMA等分析结果表明,硬段含量的增加使软段结晶的不完善程度增大,并使硬段的结晶趋于完善,而软段结晶的完善程度决定了维持暂时形状的能力,所以形变固定率随着硬段增加而下降。同时IR结果证明,HD I形成的硬段间的氢键作用更强,从而得到了比芳香族形状记忆聚氨酯更高的形变回复率。

Shape memory polyurethanes based on aliphatic diisocyanate HDI were synthesized with different hard segment contents to study the shape memory effect affected by hard segment. DSC and DMA showed that with more contents of hard segment the crystallization of soft segment became more imperfect, while the hard segments were better crysta｜lized. As soft segment crystalline decreased the shape fixity of SMPUs de- clined. It was also demonstrated by IR analysis that the hydrogen bonding between HDI based hard segments was stronger than those among aromatic ones, therefore higher shape recovery was acquired.