基于共价-非共价交织生物基聚酯的结构仿生与自修复驱动器研究

It is a frontier issue in the field of materials science to enrich the locomotion forms of smart actuators by structural bionics for the demand of their multifunctional applications under complicated conditions. However, it is a challenge to shape and reprocess complex bionic structures due to the harsh processing conditions of existing actuator materials. This project is proposed to design and synthesize a biopolyester with hydrogen bonding induced crystalline structure and covalent-noncovalent dual network structure, which is expected to show shape programmable and reprocessing performance at ambient temperature. This work would solve the key problem that it is difficult to shape low-melting-point polymer with low melt strength. And on this basis, we would fabricate a variety of bionic structured smart actuators through mimicking the geometric structure of natural organisms and ambient temperature processing. The covalent-noncovalent dual crosslinking network is expected to endow the biopolyester with excellent mechanical properties and fast self-healing ability at ambient temperature, which would solve the key issue that noncovalent crosslinked self-healing materials usually have poor mechanical performance. In addition, the moisture induced actuation properties of the biopolyester actuator under the influence of crystalline structure and dual network structure would be studied, and the locomotion forms of bionic structured actuator would also be explored. The resulted self-healing, bionic structured actuators with ambient temperature processability would extend their multifunctional applications under complicated conditions, such as biomedicine, aerospace, etc.

通过结构仿生赋予智能驱动器丰富的驱动形式，满足复杂条件下的多功能化应用需求是材料科学领域的前沿问题，但受现有驱动材料苛刻的加工条件限制，难以实现复杂仿生结构的加工成型及二次加工。本项目拟设计与合成具有共价-非共价交织结构的生物基聚酯，基于氢键诱导结晶结构与共价交联网络的协同作用，实现其室温可塑与二次加工，解决低熔点聚合物熔体强度低、难以加工成型的共性关键问题；并通过对自驱动生物体的几何结构仿生，室温加工制备多种仿生结构智能驱动器。通过调控共价-非共价交织结构赋予驱动材料优良的力学性能与室温、快速自修复性能，解决非共价键交联自修复材料力学性能差这一关键难题。阐明共价-非共价交织结构与主链结晶结构对生物基聚酯湿度驱动性能的协同调控机制，以及仿生结构对材料湿度驱动行为的影响规律，集成室温加工结构仿生、自修复与智能驱动响应等功能，拓展智能驱动器在生物医药、航空航天等复杂条件下的多功能化应用。

柔性智能驱动器是一类能够通过改变自身形状、体积、模量等对外界刺激做出响应的智能材料。通过模仿自然界生物的三维形状多样性，可赋予柔性驱动器丰富的运动方式和结构功能稳定性；然而，这些复杂结构驱动器的三维几何形状成型及重构仍然是个巨大挑战，极大限制了软体驱动器的多功能应用。针对上述瓶颈问题，本项目设计合成了具有共价-非共价交织结构的生物基聚酯，基于氢键诱导结晶结构与共价-非共价交联网络的协同作用，实现其室温可塑与二次加工，解决低熔点聚合物熔体强度低、难以加工成型的关键难题。阐明了共价-非共价交织结构对材料自修复性能与力学性能的影响机制，突破了非共价键交联自修复材料力学性能差这一共性问题。通过对生物体的几何结构仿生，室温加工制备了多种仿生结构智能驱动器，并采用有限元力学分析揭示了仿生结构对材料智能驱动行为的影响规律，为结构仿生自修复驱动器的多功能化应用奠定基础。相关研究成果在Adv. Mater., Nat. Commun., Adv. Funct. Mater., ACS Nano, Nano Lett., Adv. Sci., Small, Chem. Mater., Mater. Horiz., Nano Energy, Biomacromolecules等重要学术期刊发表SCI论文40篇，4篇论文入选ESI高被引论文；申请中国发明专利2件，授权1件；培养博士研究生2名，硕士研究生5名。作为3个执行主席之一成功组织了2020年可逆交联高分子学术论坛，在中国化学会年会、全国高分子学术论文报告会等重要会议做邀请报告10余次。项目按任务计划认真执行，深入研究共价-非共价交织结构调控制备具有优良力学性能与室温成型、自修复性能的智能驱动材料相关基础问题，取得重要创新性研究成果，全面出色地完成了预期目标。