Sulfur copolymers with high sulfur content find a broad range of applications from Li–S batteries to catalytic processes, self-healing materials, and the synthesis of nanoparticles. Synthesis of sulfur-containing polymers via the inverse vulcanization technique gained a lot of attention due to the feasibility of the reaction to produce copolymers with high sulfur content (up to 90 wt %). However, the interplay between the cross-linker and the structure of the copolymers has not yet been fully explored. In the present work, the effect of the amount of 1,3-diisopropenyl benzene (DIB) cross-linker on the structural stability of the copolymer was thoroughly investigated. Combining X-ray diffraction and differential scanning calorimetry, we demonstrated the partial depolymerization of sulfur in the copolymer containing low amount of cross-linker (<30 wt % DIB). On the other hand, by applying NMR and electron paramagnetic resonance techniques, we have shown that increasing the cross-linker content above 50 wt % leads to the formation of radicals, which may severely degrade the structural stability of the copolymer. Thus, an optimum amount of cross-linker is essential to obtain a stable copolymer. Moreover, we were able to detect the release of H₂S gas during the cross-linking reaction as predicted based on the abstraction of hydrogen by the sulfur radicals and therefore we emphasize the need to take appropriate precautions while implementing the inverse vulcanization reaction.

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反相硫化硫共聚物的NMR和EPR结构分析及稳定性研究

高硫含量的硫共聚物有着广泛的应用，从锂硫电池到催化过程、自修复材料和纳米粒子的合成。通过逆向硫化技术合成含硫聚合物由于可以反应生产高硫含量（高达 90 wt%）的共聚物而受到广泛关注。然而，交联剂和共聚物结构之间的相互作用尚未得到充分探索。在本工作中，深入研究了1,3-二异丙烯基苯（DIB）交联剂的量对共聚物结构稳定性的影响。结合X射线衍射和差示扫描量热法，我们证明了含有少量交联剂（<30 wt% DIB）的共聚物中硫的部分解聚。另一方面，通过应用NMR和电子顺磁共振技术，我们已经表明，将交联剂含量增加到50wt％以上会导致自由基的形成，这可能会严重降低共聚物的结构稳定性。因此，交联剂的最佳用量对于获得稳定的共聚物至关重要。此外，我们能够检测到交联反应过程中H 2 S气体的释放，正如基于硫自由基夺取氢所预测的那样，因此我们强调在实施逆硫化反应时需要采取适当的预防措施_。