3,13-Di(cyclic carbonate) double decker silsesquioxane, a new difunctional polyhedral oligomeric silsesquioxane (POSS), was successfully synthesized. By using this POSS macromer, the organic–inorganic poly(hydroxyl urethanes) (PHUs) were synthesized with POSS cages in the main chains. Compared to the neat PHU, the organic–inorganic PHUs displayed improved thermomechanical properties. The organic–inorganic PHUs were microphase-separated, and the main-chain POSS cages were self-assembled into the nanodomains in the size of 10–30 nm. It was found that the POSS nanodomains acted as the nano-cross-linking points of physically cross-linked networks. Although the linear organic–inorganic PHUs were soluble in common organic solvents, they were capable of displaying the thermomechanical properties similar to cross-linked PHU elastomers. Owing to the physical cross-linking, the organic–inorganic PHUs were endowed with shape memory properties. In the meantime, the organic–inorganic PHUs can be reprocessed at elevated temperature; the tensile mechanical strength can be recovered up to 90%. The reprocessing properties resulted from the transcarbamoylation reaction of hydroxyurethane structural units other than the disintegration of POSS nanodomains at elevated temperature. The reprocessing properties can be utilized to program the original shapes of shape memory polymers.

中文翻译：

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主链中具有双层倍半硅氧烷的聚（羟基氨基甲酸酯）：合成，形状恢复和后处理性能

成功合成了一种新型的双功能多面体低聚倍半硅氧烷3,13-Di（环状碳酸酯）双层倍半硅氧烷。通过使用该POSS大分子单体，可以在主链中以POSS笼子合成有机-无机聚（羟基氨基甲酸酯）（PHU）。与纯PHU相比，有机-无机PHU显示出改善的热机械性能。有机-无机PHUs是微相分离的，主链POSS笼子可自组装成尺寸为10–30 nm的纳米域。发现POSS纳米域充当物理交联网络的纳米交联点。尽管线性有机-无机PHU可溶于常见的有机溶剂，但它们具有与交联PHU弹性体相似的热机械性能。由于物理交联，有机-无机PHU具有形状记忆特性。同时，有机-无机PHU可以在高温下进行后处理。拉伸机械强度最高可恢复到90％。后处理性能是由羟基氨基甲酸酯结构单元的氨基甲酸酯化反应引起的，而不是在高温下分解POSS纳米域。可以利用后处理属性来编程形状记忆聚合物的原始形状。除了在高温下分解POSS纳米域以外，羟基苯甲酸酯结构单元的氨基甲酸酯化反应还产生了后处理性能。可以利用后处理属性来编程形状记忆聚合物的原始形状。除了在高温下分解POSS纳米域以外，羟基苯甲酸酯结构单元的氨基甲酸酯化反应还产生了后处理性能。可以利用后处理属性来编程形状记忆聚合物的原始形状。