Fabrication of spider silk-inspired bio-based polymeric materials under dynamic nanoconfinement as high-strong, ultra-tough, and multifunctional plastic substitutes

Abstract

The preparation of degradable bio-based materials with superhigh strength and toughness persists an enormous challenge. The natural spider silk presents ultrahigh tensile strength along with fracture toughness, due to the nanoconfinement effect of hydrogen-bonded crystalline β-sheets on the soft amorphous protein matrix. Herein, under inspiration of nanoconfinement effect in spider silk, an ingenious approach is proposed for fabricating a high-strong and ultra-tough soy protein (SP)-based material with dynamic nanoconfinement phases induced by tannic acid (TA) as hydrogen bond (H-bond) cross-linkers between hyperbranched polyester (HBPE) plasticizer and SP matrix molecules. Due to H-bond crosslinked dynamic nanoconfinement, the fabricated SP/HBPE/TA film reveals a superior tensile strength of 44.6 MPa together with ultrahigh toughness of 44.7 MJ m−3, surpassing its kind and other bio-based, and its toughness even outperforms common plastic-based materials. Additionally, the reversibility of the H-bonds and hydrophobic structure in nanoconfinement results in film with excellent recyclability and water resistance. The final film exhibits antioxidant and antibacterial properties after incorporating of TA. In addition, it also shows effective UV-shielding performance. This work affords a novel biomimetic strategy for fabricating fully degradable and multifunctional bio-based materials with integrated outstanding strength and toughness, for potential application in plastic waste remediation.