We developed a polyurethane material has an excellent self-healing ability as well as mechanical strength. This system was achieved based on dual-crosslinked Diels-Alder (DA) covalent bonding reaction. The first cross-linking point is realized by the DA bonding of polyurethane chain. Because of grafted maleimide group, the maleimide functionalized GO (mGO) sheets can be regarded as analogous cross-linker and provide the second cross-linking point in the system. We investigated and compared the effects of as-produced GO and mGO loading and maleimide functionalization on the mechanical properties and healing efficiency of composites. As a result, compared with those of the pure polyurethane and composites filled with the GO, such maleimide functionalization is found to effectively improve the compatibility between mGO and polymer matrix, increasing mechanical properties and healing efficiency of polyurethane composites. The mechanical properties and healing efficiency of polyurethane can be tuned readily by varying mGO concentration. The healing efficiencies were up to 99% for the nanocomposite containing mGO. These results confirm maleimide functionalization improved dispersion and interfacial interaction between the fillers and the polyurethane matrix.

我们开发了一种具有出色的自愈能力以及机械强度的聚氨酯材料。该系统是基于双交联的Diels-Alder（DA）共价键合反应实现的。第一个交联点是通过聚氨酯链的DA键实现的。由于接枝了马来酰亚胺基团，因此可以将马来酰亚胺官能化的GO（mGO）片材视为类似的交联剂，并在系统中提供第二个交联点。我们调查并比较了GO和mGO的负载量以及马来酰亚胺官能化对复合材料的机械性能和修复效率的影响。结果，与纯聚氨酯和填充有GO的复合材料相比，这种马来酰亚胺官能化可有效改善mGO与聚合物基质之间的相容性，提高聚氨酯复合材料的机械性能和修复效率。聚氨酯的机械性能和愈合效率可以通过改变mGO浓度轻松进行调整。含有mGO的纳米复合材料的治愈率高达99％。这些结果证实马来酰亚胺官能化改善了填料和聚氨酯基体之间的分散性和界面相互作用。