Bioinspired strategy for the fabrication of fast-curing, tough, and high-strength phenolic resins

Phenolic resins (PRs) find extensive use in adhesives and constructions, but they suffer from low curing rate and high brittleness. Herein, we drew inspiration from the lobster sclerotization process and proposed a simple approach to fabricate PRs by integrating pyrogallol-functionalized graphene nanoplatelets (PG@GnPs), amine-terminated hyperbranched phosphonitrilic chloride trimer (HPNC), and phenol formaldehyde (PF) resin. The resulting PRs exhibited significant improvements in comprehensive performance. The onset curing temperature decreased from 115.6 to 101.7 degrees C, while the adhesion work increased by 126.5% and the toughness increased by 494%. Additionally, the wet bonding strength increased by 68.7% and the flexural strength increased by 208%. The accelerated curing rate was attributable to the oxidative crosslinking between catechol moieties in pyrogallol and amino groups in HPNC under alkaline conditions, as well as the high reactivity between pyrogallol or amino groups and PF chains. The outstanding mechanical properties were resulted from the synergistic enhancement effects of PG@GnPs and HPNC, which effectively transferred and absorbed energy upon loading. Overall, this work presented an attractive design strategy for developing high-performance and multifunctional polymer composites.Highlights A bioinspired strategy was proposed for preparing advanced phenolic resins. PG@GnPs were produced via a green and low-cost ball milling method. Adhesion work and toughness increased by 126.5% and 494%, respectively. Bonding and flexural strength have improved by 68.7% and 208%, respectively. Significantly accelerated curing rate was achieved. Preparation of fast-curing, tough, and high-strength phenolic resins inspired by the lobster cuticular sclerotization nature. image