Biocompatible silk as natural protein fiber, the presence of large amounts of waste in the production, processing and weaving during and after use. Based on the principle of sustainable development, the research team uses Professor Xu Weilin independent patent equipment, and physical recovered waste silk, preferably retains an excellent structure and properties of silk fibroin body without secondary pollutants. However, physical recycling unmodified silk fibroin powder in multistage polymer composite structure is formed, when high powder content, the lower the mechanical properties of composite materials, limit the full application of the silk fibroin powder. Thus, without chemical modification, and how to improve the toughness of the composite particles of micron-sized filler content challenges remain high. Recently, Textiles University, Wuhan TF Professor Xu Weilin binding theory immersion precipitation and solvent evaporation shaped molding theory, to break the traditional optimization interfacial chemical modification, by a physical forming method of modulating the polymerization the interface between the filler particles and the assembly method with the polymer matrix chains force to prepare a toughened polyurethane / unmodified silk fibroin powder composite film (PU-SF). The work titled \”Fabrication of High-toughness Polyurethane / FibroinComposite without Interfacial Treatment and its Toughening Mechanism\” published in on \”ACS Applied Materials & Interfaces\”, the first author Dr. Zhang Chunhua , corresponding author Professor Professor Liu Xinhe Xu Weilin. Strain curve [123 –
Figure 1 a conventional immersion precipitation method, solvent evaporation method and the conventional binary solvent system immersed SF PU-50% stress of the composite film prepared by precipitation ] at 50 wt% SF content, using a binary solvent system immersion precipitation PU-50% SF composite membrane prepared by, elongation at break and toughness than conventional immersion precipitation film were prepared to improve the compound
145.1% and 1670.9% ; more conventionalPreparation of composite membranes solvent evaporation method elongation at break and toughness are increased 11733.0% and 6000.0% .
FIG 2 a conventional immersion precipitation method, solvent evaporation method and the conventional binary solvent system immersion precipitation film PU PU-50% SF SEM view of a composite film prepared by thermal and dynamic mechanical properties [ 123] PU-50% prepared by the conventional immersion precipitation SF irregular porous structure composite film, PU-50% SF composite membrane prepared in a conventional solvent evaporation method multiple cracks dense structure, and the two study PU-50% SF composite membranes prepared membered immersion precipitation solvent system is unique compact microporous structure. Figure 3 a conventional immersion precipitation method, solvent evaporation method and the conventional binary solvent system immersion precipitation interfacial shear strength between the PU and prepared by silk fibroin by microspheres experimental analysis removably adhered found that immersion precipitation binary solvent system using a composite film prepared by the PU and good interfacial force SF. FIG 4 a conventional immersion precipitation method, solvent evaporation method and the conventional binary solvent system immersed Tensile Fracture Mechanisms prepared by PU-50% SF precipitated composite film Conventional immersion the precipitate PU-SF composite membrane prepared by, due to the greater porosity, and irregular effects macroporous weak junction between the SF and the PU, so that the lower stress of the composite film; PU-SF composite membrane prepared by the conventional solvent evaporation, the external force, stress concentration is easy, rapid expansion of internal cracks lead to material failure. The study used the binary solvent system PU-SF composite membrane prepared by immersion precipitation, compression action capable of binding strengths and immersion precipitation during solvent evaporation induced phase transition in the molecular chain, the formula for unique tight \”fishnet\” structure, and good interfacial force between PU and SF, the external force, can be excellent in stress between the SF and the conductive PU improves the toughness of the composite. This work is a waste recycling and reuse provides a simple and practical method for the preparation of imitation silk and other fibers have good toughness and biomimetic materials offer a new strategy. Document link: https: //pubs.acs.org/doi/10.1021 / acsami.0c03936
FIG 2 a conventional immersion precipitation method, solvent evaporation method and the conventional binary solvent system immersion precipitation film PU PU-50% SF SEM view of a composite film prepared by thermal and dynamic mechanical properties [ 123]
