High-performance polyacrylate oligomers enabled by disulfide networks

Abstract

Unsaturated acrylate oligomers exhibit low viscosity and appropriate flowability, making them ideal candidates in the coatings industry. The effective development and optimization of polyacrylate resins continue to be a major focus in the field of high-performance material design. However, the selectivity of the monomer reaction poses a challenge to fundamentally change the molecular structure of the polymer, and the filler reinforcement method exists the problem of long-term performance instability. In this paper, we designed and constructed a new class of crosslinking agents, which were synthesized by esterification between thioctic acid (TA) with inherent photosensitive S-S motifs and several small molecular glycidyl ethers, including 1,4-butanediol diglycidyl ether (1,4-BDE), 1,6-hexanediol diglycidyl ether (1,6-HDE), 1,3-benzenediol diglycidyl ether (1,3-BDE), and bisphenol A diglycidyl ether (BADE). By incorporating a specific proportion of the crosslinking agent into the polyacrylate oligomer, the performances of the cured film were obviously improved. Furthermore, bisphenol A glycidyl ether-modified disulfide system (BAT) with variable participation ratios was established to enhance thermal and mechanical properties. The optimized BAT coating demonstrated robust tensile strength (36.64 MPa), toughness (1.34 MJ m⁻³), and ideal T_g (126.7 °C), as well as attractive hydrophobicity (97.6 °) and self-healing ability. As a proof of concept, the BAT₃ oligomer was used as the main resin for high-load filler coating, which possessed suitable viscosity (212 Pa·s) and mechanical strength, with resistance to aging and low-temperature cracking. Overall, this work provides an opportunity to develop high-performance polyacrylate materials based on dynamic cross-linking bonds and can be applied well in high-load filler coatings.