High Interfacial Adhesion of PET/Rubber Composites by a New Eco-Friendly Dipping System

Fiber-reinforced rubber composites (FRRC) are widely employed in critical industries, such as the automotive, aerospace, and construction protection industries, due to their excellent deformation resistance and superior mechanical properties. Polyester (PET) fiber, with its outstanding dimensional stability and cost-effectiveness, has increasingly replaced nylon as the primary reinforcement in radial tires. However, the lack of polar groups on PET surfaces results in poor interfacial adhesion with rubber matrices, limiting composite performance. Traditional resorcinol-formaldehyde-latex (RFL) dipping systems enhance adhesion but raise environmental and health concerns due to the release of hazardous substances. This study develops a novel eco-friendly γ-Aminopropyltriethoxysilane (KH550)-glycerol triglycidyl ether-sorbitol glycidyl ether-2-Ethyl-4-methylimidazole-latex (KG-SML) dipping system to enhance PET-rubber interfacial adhesion. At an optimal KH550 dosage of 2 phr, the 180° peel force and H pull-out force reached maximum values of 23.5 N/piece and 109.0 N, respectively, significantly surpassing the performance of the conventional RFL system. The KG-SML system offers an effective and sustainable alternative to RFL, with enhanced interfacial performance and less environmental impact.