Double-Decker Silsesquioxane-Grafted Polysilsesquioxane Hybrid Films as Thermal Insulation Materials
Double-Decker Silsesquioxane-Grafted Polysilsesquioxane Hybrid Films as Thermal Insulation Materials
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DOI：
10.1021/acsapm.2c01743
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发表时间：
2022-12
影响因子：
5
通讯作者：
T. Hamada;Sakino Takase;Arata Tanaka;K. Okada;Susumu Mineoi;A. Uedono;J. Ohshita
中科院分区：
文献类型：
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作者：
T. Hamada;Sakino Takase;Arata Tanaka;K. Okada;Susumu Mineoi;A. Uedono;J. Ohshita
为了实现可持续发展的社会，需要开发具有高绝热性能和热稳定性的绝热体。在聚倍半硅氧烷（PSQs）中，其有望作为下一代绝热材料，交联单元的引入允许通过形成分子内空隙空间来改善绝热性能。然而，这通常伴随着透明度和稳定性的丧失。为了避免这个问题，氢化二甲基甲硅烷基化的低聚甲基倍半硅氧烷和乙烯基官能化的双层倍半硅氧烷（乙烯基-DDSQ）（其是高度热稳定的单元）之间的氢化硅烷化反应进行，以获得无聚集的DDSQ接枝的PSQ膜。由于双层倍半硅氧烷（DDSQ）分子的高亲水性，引入了大量的乙烯基-DDSQ，得到了无色透明的DDSQ接枝PSQ膜，而DDSQ分子没有聚集。DDSQ接枝PSQ薄膜的热扩散系数随DDSQ用量的增加而降低，从1.21 × 10- 7下降到1.02 × 10- 7 m2/s。尽管对于先前报道的含多面体低聚倍半硅氧烷的杂化膜观察到类似的趋势，但是DDSQ接枝的PSQ膜的硬度随着乙烯基-DDSQ含量的增加而降低，并且它们的热稳定性更高（超过400 °C），具有分别为438-463 °C和495-523 °C的更高的5%质量损失温度和10%质量损失温度值。因此，DDSQ接枝PSQ膜的高绝热性能和热稳定性使其成为下一代绝热材料的有前途的材料。
The development of thermal insulators possessing high thermal insulating properties and thermal stability is desired for realizing a sustainable society. In polysilsesquioxanes (PSQs), which are promising as next-generation thermal insulation materials, the introduction of cross-linking units allows improving the thermal insulating properties through formation of intramolecular void spaces. However, this is usually accompanied by a loss of transparency and stability. To circumvent this issue, the hydrosilylation reaction between hydrodimethylsilylated oligomethylsilsesquioxane and vinyl-functionalized double-decker silsesquioxane (vinyl-DDSQ), which is a highly thermally stable unit, was conducted to obtain aggregation-free DDSQ-grafted PSQ films. The high miscibility of the double-decker silsesquioxane (DDSQ) molecule allowed introducing a high amount of vinyl-DDSQ, and colorless and transparent DDSQ-grafted PSQ films were obtained without aggregation of DDSQ molecules. The thermal diffusivities of the DDSQ-grafted PSQ films decreased from 1.21 × 10–7to 1.02 × 10–7m2/s with increasing the DDSQ amount from 5 to 25 mol %. Although a similar trend was observed for the previously reported polyhedral oligomeric silsesquioxane-containing hybrid films, the hardness of the DDSQ-grafted PSQ films decreased with increases in the vinyl-DDSQ content, and their thermal stability was higher (over 400 °C), with higher 5% mass loss temperature and 10% mass loss temperature values of 438–463 °C and 495–523 °C, respectively. Therefore, the high thermal insulating properties and thermal stability of the DDSQ-grafted PSQ films render them promising materials for next-generation thermal insulators.