γ-AlOOH-Assisted Immobilization of Antioxidants on Glass Fabric to Enhance Mechanical Properties and Durability of Composites in Alkaline Environments

Enhancing the durability of ultraviolet-cured-in-place pipe (UV-CIPP) in alkaline environments remains challenging due to its long-term exposure to concrete pore solution from the original pipe. Herein, a novel strategy that γ-AlOOH coating assists to immobilize Irganox 1010 onto glass fibric (GF) was proposed for simultaneously improving alkaline corrosion resistance and mechanical properties of UV-CIPP. Through the beneficial bridging of γ-AlOOH with the coupling agent, Irganox 1010 was immobilized on the GF (GF-Al-g-1010) surface through hydrogen bonding and covalent bonding. The leaching of Si²⁺ from the GF backbone of unsaturated polyester resin (UP)/GF-Al-g-1010 composite was reduced by 40.60% and the hydrolyzed alcohol products decreased by 47.1%. Meanwhile, the mechanical properties of UP/GF-Al-g-1010 remained well preserved. The flexural and tensile modulus retained at 99.0% and 96.3%, respectively. The immobilization of Irganox 1010 at the UP/GF interface formed a protective hydrophobic layer and stabilized free radicals, which together inhibited resin degradation and reduced interface debonding. Moreover, the flexural strength and modulus of composites increased by 36.5% and 38.4%, respectively. The chemical bonding between GF-Al-g-1010 and UP chains enhanced interfacial adhesion. In summary, this work will facilitate the design of UV/thermal dual-cured composites with high strength and alkaline corrosion resistance for pipeline rehabilitation.