Abstract A polydimethylsiloxane-α,ω-diol (UHMW-PDMS) with unusually high molecular weight (Mw = 1,395,000 g/mol) and narrow polydispersity (PDI = 1.49), free of monomer or catalyst traces, was obtained in high yield by a scalable process, easy to achieve (bulk anionic ring-opening polymerization of octamethylcyclotetrasiloxane catalyzed by tetramethylammonium hydroxide). Spectral and thermogravimetric analysis confirmed the theoretical structure, purity and thermal stability of the polymer. Individual or aggregated macromolecules were assessed by dynamic light scattering (DLS) and visualized by microscopic methods (TEM, AFM). The mechanical, dielectric, and thermal performances of application interest for this polymer were evaluated on samples of chemically defined elastomer cUHMW-PDMS prepared by condensation crosslinking through the polymer chain ends with tetraethylorthosilicate. The results were compared with those obtained on a lower molecular weight (Mw = 720,100 g/mol, PDI = 1.87) homologue (PDMS) prepared and processed in identical conditions, but also with a commercial silicone elastomer. UHMW-PDMS-based elastomer shows superior results on elastic recovery and stress decay at high elongation, as compared with reference samples.

中文翻译：

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从超高分子量聚二甲基硅氧烷到超软弹性体

摘要 聚二甲基硅氧烷-α,ω-二醇 (UHMW-PDMS) 具有异常高的分子量 (Mw = 1,395,000 g/mol) 和窄多分散性 (PDI = 1.49)，不含单体或催化剂痕迹，通过以下方法以高产率获得。工艺可扩展，易于实现（四甲基氢氧化铵催化八甲基环四硅氧烷的本体阴离子开环聚合）。光谱和热重分析证实了聚合物的理论结构、纯度和热稳定性。单个或聚集的大分子通过动态光散射 (DLS) 进行评估，并通过显微方法 (TEM、AFM) 进行可视化。机械、电介质、该聚合物的应用兴趣和热性能在化学定义的弹性体 cUHMW-PDMS 样品上进行了评估，该样品是通过聚合物链端与四乙基原硅酸酯缩合交联制备的。将结果与在相同条件下制备和加工的较低分子量 (Mw = 720,100 g/mol, PDI = 1.87) 同系物 (PDMS) 以及商业有机硅弹性体获得的结果进行比较。与参考样品相比，基于 UHMW-PDMS 的弹性体在高伸长率下显示出优异的弹性恢复和应力衰减结果。