Sun Jian, Liang Mingrui, Yin Lu, Rivers Geoffrey, Hu Guangwei, Pan Qinmin, Zhao Boxin
Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Centre for Bioengineering and Biotechnology, Institute for Polymer Research, University of Waterloo, Waterloo N2L 3G1, Canada.
Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
ACS Appl Mater Interfaces. 2023 Aug 23;15(33):39786-39796. doi: 10.1021/acsami.3c05041. Epub 2023 Aug 14.
The development of polymeric nanocomposites with dynamic covalent adaptable networks and biobased nanomaterials has been a promising approach toward sustainable advanced materials, enabling reprogramming and recycling capabilities. Herein, a core-shell nanohybrid of functionalized cellulose nanocrystals (CNCs) is explored to provide crucial interfacial compatibility for improving the covalent adaptable networks of epoxy-thiol vitrimers in fracture resistance. The poly(ε-caprolactone) (PCL) shells grafted from CNC surfaces can be cross-linked with the covalent adaptable networks via a hot-pressing transesterification process. According to the additive concentration and annealing temperature, the stress relaxation behavior of nanohybrid vitrimer composites can be effectively regulated by the core-shell PCL-grafted CNC (CNC-PCL) nanohybrids from a dispersed to cross-linked interaction. The addition of 15 wt % of the core-shell CNC-PCLs exhibits the reinforced improvement of nanohybrid vitrimer composites in the average Young's modulus of 2.5×, fracture stress of 5.4×, and fracture strain of 2.0×. The research findings might have profound implications for developing synergistic interfacial compatibility between dynamic vitrimer networks and functional nanoparticles for advanced polymeric nanocomposites.
开发具有动态共价适应性网络和生物基纳米材料的聚合物纳米复合材料，是迈向可持续先进材料的一种很有前景的方法，能够实现重新编程和回收利用。在此，探索了一种功能化纤维素纳米晶体（CNC）的核壳纳米杂化物，以提供关键的界面相容性，从而改善环氧硫醇类可塑交联网络聚合物的抗断裂性能。从CNC表面接枝的聚（ε-己内酯）（PCL）壳层可以通过热压酯交换过程与共价适应性网络交联。根据添加剂浓度和退火温度，核壳接枝PCL的CNC（CNC-PCL）纳米杂化物可以有效地调节纳米杂化可塑交联网络聚合物复合材料的应力松弛行为，使其从分散相互作用转变为交联相互作用。添加15 wt%的核壳CNC-PCL可使纳米杂化可塑交联网络聚合物复合材料的平均杨氏模量提高2.5倍、断裂应力提高5.4倍、断裂应变提高2.0倍。这些研究结果可能对开发动态可塑交联网络聚合物与功能性纳米粒子之间的协同界面相容性以用于先进聚合物纳米复合材料具有深远意义。
