Presented here is a combined computational and experimental study on the thermal initiation process of the twin polymerization. Although thermally initiated twin polymerization offers a versatile scheme for obtaining hybrid organic/inorganic nanocomposite materials, the mechanism for its initiation is very different from the proton-initiated twin polymerization. In this study, the basic mechanism of the early steps of the polymerization process of 4 H,4 H'-2,2'-spirobi[benzo[d][1,3,2]dioxasiline] was investigated by using electronic structure calculations in conjunction with experimental differential scanning calorimetry studies. This way, the influences on the thermally initiated twin polymerization process could be analyzed in detail. The previous mechanistic hypotheses are systematically assessed herein to show that, based on the results, a new hypothesis for an initiation mechanism can be formulated that is in agreement with all experimental observations. These results suggest that, before the formation of the polymer networks, the thermal initiation starts with the formation of low-molecular-weight fragments that react to yield acidic groups. If a sufficient amount of these form, the reaction is ultimately funneled into a mechanism similar to that of proton-initiated twin polymerization.

中文翻译：

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双聚合过程热引发的电子结构计算和实验研究。

本文介绍的是对双聚合热引发过程的综合计算和实验研究。尽管热引发的双聚合为获得有机/无机纳米复合杂化材料提供了一种通用的方案，但其引发机理与质子引发的双聚合非常不同。在这项研究中，通过电子结构计算研究了4 H，4 H'-2,2'-螺双[苯并[d] [1,3,2]二氧杂苯胺]聚合过程早期步骤的基本机理。结合实验差示扫描量热法研究。这样，可以详细分析对热引发双聚合过程的影响。本文对之前的机械假设进行了系统的评估，以表明，根据结果​​，可以提出一种与所有实验观察结果一致的引发机理的新假设。这些结果表明，在形成聚合物网络之前，热引发始于形成低分子量片段的反应，这些片段反应生成酸性基团。如果有足够数量的这些形式，则该反应最终会漏入与质子引发的双聚合反应相似的机理中。