Feng Haijun, Zheng Ning, Peng Wenjun, Ni Chujun, Song Huijie, Zhao Qian, Xie Tao
State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P. R. China.
ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou, 311215, P. R. China.
Nat Commun. 2022 Jan 19;13(1):397. doi: 10.1038/s41467-022-28085-2.
Thermoset polymers are indispensable but their environmental impact has been an ever-increasing concern given their typical intractability. Although concepts enabling their reprocessing have been demonstrated, their practical potential is limited by the deteriorated performance of the reprocessed materials. Here, we report a thiourea based thermoset elastomer that can be reprocessed with enhanced mechanical properties. We reveal that the thiourea bonds are dynamic which leads to the reprocessibility. More importantly, they can undergo selective oxidation during high temperature reprocessing, resulting in significant chemical strengthening within certain reprocessing cycles. This is opposite to most polymers for which reprocessing typically results in material deterioration. The possibility of having materials with inherent reprocessing induced performance enhancement points to a promising direction towards polymer recycling.
热固性聚合物不可或缺，但鉴于其典型的难加工性，它们对环境的影响一直备受关注。尽管已证明有实现其再加工的概念，但其实际潜力受到再加工材料性能下降的限制。在此，我们报道了一种基于硫脲的热固性弹性体，它可以再加工且机械性能增强。我们发现硫脲键是动态的，这导致了可再加工性。更重要的是，它们在高温再加工过程中会发生选择性氧化，在一定的再加工循环内导致显著的化学强化。这与大多数聚合物相反，对于大多数聚合物而言，再加工通常会导致材料性能下降。具有固有再加工诱导性能增强的材料的可能性为聚合物回收指出了一个有前景的方向。
