Respiratory Department, Shenzhen Children's Hospital, 518038, Shenzhen, China.
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Institute of Functional Materials, Research Base of Textile Materials for Flexible Electronics and Biomedical Applications (China Textile Engineering Society), Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, Donghua University, 201620, Shanghai, China.
Nat Commun. 2023 Apr 18;14(1):2218. doi: 10.1038/s41467-023-37850-w.
Fibers, with over 100 million tons produced each year, have been widely used in various areas. Recent efforts have focused on improving mechanical properties and chemical resistance of fibers via covalent cross-linking. However, the covalently cross-linked polymers are usually insoluble and infusible, and thus fiber fabrication is difficult. Those reported require complex multiple-step preparation processes. Herein, we present a facile and effective strategy to prepare adaptable covalently cross-linked fibers by direct melt spinning of covalent adaptable networks (CANs). At processing temperature, dynamic covalent bonds are reversibly dissociated/associated and the CANs are temporarily disconnected to enable melt spinning; at the service temperature, the dynamic covalent bonds are frozen, and the CANs exhibit favorable structural stability. We demonstrate the efficiency of this strategy via dynamic oxime-urethane based CANs, and successfully prepare adaptable covalently cross-linked fibers with robust mechanical properties (maximum elongation of 2639%, tensile strength of 87.68 MPa, almost complete recovery from an elongation of 800%) and solvent resistance. Application of this technology is demonstrated by an organic solvent resistant and stretchable conductive fiber.
纤维每年的产量超过 1 亿吨，已广泛应用于各个领域。最近的研究重点是通过共价交联来提高纤维的机械性能和耐化学性。然而，通过共价键交联的聚合物通常不溶不熔，因此纤维的制备较为困难。已报道的方法需要复杂的多步制备工艺。本文提出了一种简便有效的策略，通过可共价适应网络（CANs）的直接熔融纺丝来制备可适应的共价交联纤维。在加工温度下，动态共价键可可逆地解离/形成，CANs 暂时断开以实现熔融纺丝；在使用温度下，动态共价键被冻结，CANs 表现出良好的结构稳定性。我们通过动态肟基-氨酯基 CANs 验证了该策略的有效性，并成功制备了具有良好机械性能（最大伸长率 2639%，拉伸强度 87.68 MPa，伸长 800%时几乎完全恢复）和耐溶剂性的可适应共价交联纤维。通过耐有机溶剂和可拉伸的导电纤维展示了该技术的应用。
