Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, Guangxi University, Nanning 530004, China; School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Disaster Prevention and Engineering Safety, Guangxi University, Nanning 530004, China.
Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Disaster Prevention and Engineering Safety, Guangxi University, Nanning 530004, China.
Int J Biol Macromol. 2022 Dec 1;222(Pt A):587-598. doi: 10.1016/j.ijbiomac.2022.09.192. Epub 2022 Sep 24.
Cellulose, as a green reinforcing agent for rubber, has excellent improvement on the tensile strength but usually accompany with a deterioration of extensibility and self-healing property. Herein, we report an efficient method to prepare robust and self-healable natural rubber/zinc dimethacrylate/carboxylated cellulose nanofibers (NR/ZDMA/CNC) composites which are constructed by a CNC participated ionic supramolecular network. Ionic supramolecular network in NR is generated by the polymerization of ZDMA during a controlled peroxide-initiated vulcanization of NR. Interestingly, NR with massive ion clusters has strong affinity with CNC, which facilitates the uniform dispersion of CNC and the compatibility between CNC and NR. Meanwhile, CNC participates into the supramolecular network via non-covalent interaction with NR chains equipped with ionic crosslinks. This greatly reduces the adverse effect of CNC on the dynamic characteristics of supramolecular network. As a result, the tensile strength of NR/ZDMA composite with 20 phr CNC could reach 4.13 MPa, while its self-healing efficiency still maintains at >80 %. Thus, NR composites with non-covalent interaction between CNC and supramolecular network display improved strength, maintained extensibility, and excellent self-healing capability. This study thus demonstrates a feasible approach to reduce the negative effect of reinforcing fillers on a self-healing rubber based on supramolecular networks.
纤维素作为一种绿色的橡胶增强剂，对拉伸强度有很好的改善作用，但通常伴随着延展性和自修复性能的恶化。在此，我们报告了一种高效的方法来制备坚固且可自修复的天然橡胶/甲基丙烯酸锌/羧基化纤维素纳米纤维（NR/ZDMA/CNC）复合材料，该复合材料由 CNC 参与的离子超分子网络构建。NR 中的离子超分子网络是通过 ZDMA 的聚合在 NR 的受控过氧化物引发硫化过程中产生的。有趣的是，具有大量离子簇的 NR 与 CNC 具有很强的亲和力，这有利于 CNC 的均匀分散和 CNC 与 NR 的相容性。同时，CNC 通过与带有离子交联的 NR 链的非共价相互作用参与超分子网络。这大大降低了 CNC 对超分子网络动态特性的不利影响。结果，在含有 20 phr CNC 的 NR/ZDMA 复合材料中，拉伸强度可达到 4.13 MPa，而其自修复效率仍保持在>80%。因此，具有 CNC 与超分子网络之间非共价相互作用的 NR 复合材料显示出增强的强度、保持的延展性和优异的自修复能力。该研究因此展示了一种可行的方法，可基于超分子网络来减少增强填料对自修复橡胶的负面影响。
