Development of Leather Fiber/Polyurethane Composite with Antibacterial, Wet Management, and Temperature-Adaptive Flexibility for Foot Care.

With the increase in the incidence of diabetes, the health care of the feet of diabetic patients becomes particularly important. Herein, leather fiber (LF) was utilized with waterborne polyhexamethylene guanidine-embedded polyurethane (PPU) to prepare network-interpenetrating LF/PPU composites as potential foot care material via a facile "paper-making" pathway. Due to the coating of PPU on LF, the release of chromium in sweat is significantly reduced. The fibrous structure endows LF/PPU with temporary hydrophobicity, air permeability, and moisture absorption and retention. Such wet management capacity can help to maintain a dry environment inside a shoe model. Moreover, the presence of PPU improves the durability of LF/PPU, and the synergistic effect of LF and PPU leads to temperature adaptive flexibility of LF/PPU, thus providing the proper strength to protect feet at low temperatures while offering flexibility in hot environments to facilitate movement. Furthermore, LF/PPU possesses antibacterial and antimildew properties, which are still effective after repeated friction. This study offers a facile and eco-friendly route to develop multifunctional composites for health wear products, especially for foot care.