Vitrimer chemistry can integrate reprocessability, recyclability, self-healing and good creep-resistance into polymers through covalent adaptive network structure. In particular, reactive processing shows great potential to convert commercial polymers into vitrimers in industrial scale. In this work, vitrimeric silicone elastomer was successfully prepared in a one-step peroxide-induced thiol-ene click reaction between thiol-terminated boronic ester and vinyl groups of commercial methylvinyl silicone rubber (MVQ) via reactive processing. It was found that MVQ vitrimer elastomer shows good reprocessability, self-healing property, excellent elasticity and a similar gel content to that of traditional peroxide-crosslinked MVQ rubbers. Based on classical Arrhenius theory, the calculated activation energy (E_a) of B–O dynamic bond in MVQ vitrimer is 28.5 kJ/mol along with a topology-freezing transition temperature (T_v) of 6.4 °C. Intriguingly, the fabricated MVQ vitrimer shows a strongly rate-dependent mechanical response, i.e., larger mechanical strength at higher deformation rate, which is mainly due to fast bond-exchange rate of the B–O bonds even at room temperature. MVQ vitrimer shows a “solid-liquid” feature, that is, exhibiting liquid-like behavior at longer obeservation time or when stretched at low strain rate while acting as solid elastomer at high strain rate. Notably, the tensile toughness (@500% strain) can obtain nearly 1.6-fold increase to 47.59 MJ/m³ from 18.58 MJ/m³ when increasing tensile speed, indicating an excellent energy-dissipative behavior especially at high deformation rate. Therefore, our work can provide guidance for molecular design and reactive processing of high-performance vitrimeric silicone elastomers toward industrial applications.

Vitrimer 化学可以通过共价自适应网络结构将可再加工性、可回收性、自修复性和良好的抗蠕变性集成到聚合物中。特别是，反应性加工显示出将商业聚合物转化为工业规模 vitrimer 的巨大潜力。在这项工作中，通过反应处理，在硫醇封端的硼酸酯和商业甲基乙烯基硅橡胶 (MVQ) 的乙烯基之间，通过一步过氧化物诱导的硫醇-烯点击反应成功制备了玻璃聚硅氧烷弹性体。结果发现，MVQ vitrimer 弹性体具有良好的再加工性、自愈性、优异的弹性和与传统过氧化物交联 MVQ 橡胶相似的凝胶含量。基于经典阿伦尼乌斯理论，计算得到活化能（E _a) 在 MVQ vitrimer 中 B-O 动态键为 28.5 kJ/mol 以及 6.4 °C 的拓扑冻结转变温度 ( T _v )。有趣的是，制造的 MVQ vitrimer 显示出强烈的速率依赖性机械响应，即在较高的变形速率下具有较大的机械强度，这主要是由于即使在室温下 B-O 键的快速键交换速率。MVQ vitrimer 显示出“固-液”特征，即在较长的观察时间或在低应变率下拉伸时表现出类似液体的行为，而在高应变率下充当固体弹性体。值得注意的是，拉伸韧性（@500% 应变）可从 18.58 MJ/m ³增加近 1.6 倍至 47.59 MJ/ m ³当增加拉伸速度时，表明具有优异的能量耗散行为，尤其是在高变形率下。因此，我们的工作可以为高性能玻璃聚硅氧烷弹性体的分子设计和反应加工提供工业应用指导。