Bioinspired Mechanically Robust Organic–Inorganic Hybridized Bio‐Adhesives With up to 50% Inorganic Components by Bi‐Continuous Phase Engineering

ABSTRACT In the traditional organic–inorganic hybrid construction method, due to the fact that inorganic substances usually exist in the form of fillers, their addition amount is limited, resulting in insignificant effects of reinforcement, toughening, and cost reduction. Inspired by the mineralization bridging mechanism in tooth repair, we have broken through the limitation that inorganic components merely serve as fillers, and used inorganic oligomers as cross‐linker to cross‐link hydroxyapatite, constructing a continuous inorganic network structure. This network is further integrated with an organic network formed from plant proteins, ultimately resulting in a unique bi‐continuous organic‑inorganic hybrid structure. Compared with the traditional hybrid method, the addition amount of inorganic phase in this bi‐continuous hybrid adhesive has increased from 0.2%–3.0% to 50%. Surprisingly, under the same inorganic content (50%), its strength and toughness are 6 and 121 times higher than traditional hybrid adhesives. In addition, this bi‐continuous hybrid plant protein adhesive has the advantages of low cost and low carbon emissions compared with urea‐formaldehyde resin. This strategy offers a promising new approach for developing high‐performance and low‐cost composite materials.