Synthesis of photoresponsive cyclic poly(dimethyl siloxane)s from monodisperse linear precursors
Synthesis of photoresponsive cyclic poly(dimethyl siloxane)s from monodisperse linear precursors
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DOI：
10.1016/j.reactfunctpolym.2020.104800
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发表时间：
2021-01-01
影响因子：
5.1
通讯作者：
Honda, Satoshi
中科院分区：
文献类型：
--
作者：
Oka, Minami;Honda, Satoshi
聚硅氧烷是工业上重要的硅基聚合物材料，其不能被碳基材料替代。在这一领域，具有非线性大分子结构的功能性聚二甲基硅氧烷（PDMS）的合成对于寻找下一代应用是必不可少的。在这里，我们报告的合成环状PDMS（C）与光裂解和可重整的六芳基联咪唑（HABI）衍生的共价键的主链从三苯基咪唑（洛啡）末端官能化的单分散线性前体（Ls）。有趣的是，L的浓度（10 mg/mL）远高于典型浓度（类似于0.1 mg/mL）的端-端环化反应主要产生单分子环化产物。此外，在无溶剂条件下光照射C，尽管C的物理状态是固体，但分子量增加。
Polysiloxanes are industrially important silicon-based polymeric materials which cannot be replaced by carbon based ones. In this area, synthesis of well-defined functional poly(dimethyl siloxane) (PDMS) with nonlinear macromolecular architectures is indispensable for finding next-generation applications. Here we report the synthesis of cyclic PDMS (C) with photocleavable and reformable hexaarylbiimidazole (HABI)-derived covalent bonds in the main chain from triphenylimidadole (lophine) end-functionalized monodisperse linear precursors (Ls). Interestingly, an end-to-end cyclization reaction of L with the concentration (10 mg/mL) much higher than that of a typical concentration (similar to 0.1 mg/mL) dominantly produced unimolecularly cyclized product. Moreover, photoirradiation to C under a solvent-free condition, molecular weight increased despite the physical state of C was solid.