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    具有形状记忆效应的硅烷化聚己内酯型聚氨酯

    Silylated PCL-Based Polyurethane with Shape Memory Effect

    • 摘要: 以烷氧基钛和聚乙二醇的混合物引发ε-己内酯本体聚合得到低聚合度(DPn为10~50)的聚己内酯(PCL)二醇,然后在N,N -二甲基甲酰胺中依次与4,4′-二苯基甲烷二异氰酸酯和3-氨丙基三乙氧基硅烷反应,脱除溶剂并经湿气交联得到硅烷化聚己内 酯型聚氨酯(SPCLU)。研究了PCL嵌段聚合度对SPCLU交联特征、结晶行为、力学性能及形状记忆性的影响。结果表明:当PCL嵌段 DPn由10增加到50时,SPCLU结晶度和熔点随之增加,弹性模量及断裂伸长率均提高;而SPCLU的交联密度随PCL嵌段DPn的增加而减小 ;由结晶度较高的嵌段(DPn为30~50)组成的SPCLU具有良好的形状记忆性,形状回复率为95%~100%,形状回复温度与PCL结晶区域 的熔程相对应。

       

      Abstract: Poly(ε-caprolactone) (PCL) diols with low average degree of polymerization (DPn is 10-50) were prepared by bulk polymerization from ε-caprolactone initiated by the mixture of PEG400 and titanium alkoxide. These PCL diols were used to react with 4,4′-diphenylmethane diisocyanate and 3-aminopropyltriethoxysilane in sequence using N,N-dimethylformamide as solvent. After removal of the solvent, the silylated PCLbased polyurethanes (SPCLU) were obtained by moisture curing. The effect of the PCL block DPn on the crosslinking, crystallization behavior, tensile properties and shape memory properties of SPCLU networks were studied in detail. Results show that the crystallinity, melting point, tensile modulus, and elongation at break of SPCLU increase with increasing the PCL block DPn from 10 to 50, whereas the crosslinking density of SPCLU decreases. The SPCLUs with PCL block of high crystallinity show good shape memory effect. The shape recovery ratio is 95%-100% and the shape recovery temperature corresponds to the crystalline melting temperature of PCL block in the copolymer.

       

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