Cerdan Kenneth, Brancart Joost, Roels Ellen, Vanderborght Bram, Van Puyvelde Peter
Department of Chemical Engineering, Soft Matter, Rheology and Technology (SMaRT), KU Leuven, Celestijnenlaan 200J, 3001 Heverlee, Belgium.
Physical Chemistry and Polymer Science (FYSC), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
Polymers (Basel). 2022 Apr 20;14(9):1657. doi: 10.3390/polym14091657.
Humins waste valorization is considered to be an essential pathway to improve the economic viability of many biorefinery processes and further promote their circularity by avoiding waste formation. In this research, the incorporation of humins in a Diels-Alder (DA) polymer network based on furan-maleimide thermoreversible crosslinks was studied. A considerable enhancement of the healing efficiency was observed by just healing for 1 h at 60 °C at the expense of a reduction of the material mechanical properties, while the unfilled material showed no healing under the same conditions. Nevertheless, the thermal healing step favored the irreversible humins polycondensation, thus strengthening the material while keeping the enhanced healing performance. Our hypothesis states a synergistic healing mechanism based on humins flowing throughout the damage, followed by thermal humins crosslinking during the healing trigger, together with DA thermoreversible bonds recombination. A multi-material soft robotic gripper was manufactured out of the proposed material, showing not only improved recovery of the functional performance upon healing but also stiffness-tunable features by means of humins thermal crosslinking. For the first time, both damage healing and zone reinforcement for further damage prevention are achieved in a single intrinsic self-healing system.
腐殖质废物的增值利用被认为是提高许多生物炼制过程经济可行性的重要途径，并且通过避免废物形成进一步促进其循环利用。在本研究中，研究了将腐殖质掺入基于呋喃-马来酰亚胺热可逆交联的狄尔斯-阿尔德（DA）聚合物网络中。在60℃下仅愈合1小时，观察到愈合效率有显著提高，但材料的机械性能有所降低，而未填充材料在相同条件下未显示出愈合效果。然而，热愈合步骤有利于腐殖质的不可逆缩聚，从而在保持增强的愈合性能的同时增强了材料。我们的假设提出了一种协同愈合机制，即腐殖质在损伤处流动，随后在愈合触发过程中发生腐殖质热交联，同时DA热可逆键发生重组。用所提出的材料制造了一种多材料软机器人抓手，它不仅在愈合后功能性能的恢复得到改善，而且通过腐殖质热交联具有刚度可调的特性。首次在单一的本征自愈合系统中实现了损伤愈合和用于进一步预防损伤的区域增强。
