Preparation of functional fiber hybrid enhanced high strength and multifunctional protein based adhesive

Abstract

Protein based adhesive is limited by poor mechanical properties and water resistance. Inspired by the structure of muscle tissue, a complex structure of layered double hydroxide (LDH) anchored chicken feather fiber (CFF) and tannic acid (TA) was constructed by self-assembly process, forming a novel organic–inorganic hybrid reinforcement structure (CFF-LDH-TA). CFF-LDH-TA was closely combined with soybean meal (SM) through covalent and hydrogen bond multiple interactions. TA simulated the function of connective tissue around fibers, significantly improving the cohesion of SM based adhesive through effective energy dissipation and load transfer. Due to the increased crosslinking density, the dry and wet shear strengths of SM/CFF-LDH-TA reached 2.12 and 1.60 MPa, respectively, which were 50 % and 214 % higher than original SM adhesive, and significantly exceeded the strength of several commercialized formaldehyde adhesives. The existence of bridging effect and sacrificial structure improved toughness of the adhesive, the work of adhesion increased by 802 %, reached 830 mJ. In addition, the SM/CFF-LDH-TA adhesive had better anti-mold and flame retardant ability. More importantly, the cost was lower than the commercial SM based adhesive. This simple and green preparation method provided a new strategy for the production of high-performance, multifunctional and economically effective SM based adhesive.