Tailoring interfacial adhesion and hydrophobicity in jute-epoxy composites via acrylic water sealer coatings

This study investigates the enhancement of mechanical and moisture-resistant properties in jute fiber-reinforced epoxy composites through water sealer coatings, exploring dilution ratios of 1:1, 1:2, and 1:3 (sealer-to-water). Tensile, flexural, and impact tests revealed that the 1:1 composite achieved the highest tensile strength (17.31 MPa), while the 1:2 composite demonstrated optimal overall performance, exhibiting the highest flexural strength (40.93 MPa), impact energy (3.75 J), tensile toughness (245.65 mJ), and the lowest water absorption (2.95%). The 1:2 coating also minimized water absorption (2.95%), outperforming the control (3.81%) and 1:3 composite (5.57%). SEM analysis demonstrated uniform fiber-matrix adhesion in the 1:2 composite, while FTIR identified key functional groups (C=O, C–O–C) that enhanced interfacial bonding and moisture resistance. A critical stiffness-toughness trade-off emerged: the 1:2 composite balanced ductility (tensile toughness: 245.65 mJ) with retained rigidity, whereas the 1:1 and 1:3 ratios exhibited reduced stiffness or excessive hydrophilicity. The findings highlight the 1:2 dilution as a cost-effective strategy to tailor natural fiber composites for structural and dynamic applications in humid environments. This work advances sustainable material design by optimizing eco-friendly coatings, offering insights for industries seeking alternatives to synthetic reinforcements. This work establishes the strategic dilution of commercial sealers as a novel, scalable, and cost-effective route for manufacturing high-performance natural fiber composites, moving beyond traditional chemical treatments.