Core-shell nanohybrid elastomer based on co-deposition strategy to improve performance of soy protein adhesive.

Abstract

Exploitation of a versatile strategy for fabricating a plant protein adhesive with outstanding adhesion and water resistance is a growing concern in the eco-friendly wood industry. Herein, a core-shell nanohybrid elastomer composed of the cellulose nanocrystal (CNC) core and elastic polyurethane shell is prepared via a co-deposition strategy, and then used as an efficient reinforcer to improve the performances of soy protein (SP) adhesive. It is found that the core-shell nanohybrid acts as a multiple crosslinker, giving rise to the construction of a stable protein adhesive system. Moreover, owing to the nanohybrid design combining strong yet tough qualities, the hard CNC serves to repair the discontinuous protein adhesion layer for a rigid and integrated system while the elastic polyurethane contributes to energy dissipation, thus endowing the protein adhesive with excellent overall cohesive strength. Given on such synergistic effects, the modified SP-based adhesive exhibits a significant improvement in both adhesion and water resistance, particularly achieving a 311.8% increase in wet adhesion strength compared to the pristine SP adhesive. This work may provide an effective guide for the preparation and practical application of high-performance plant protein-based adhesive.