The role of interactions at interfaces of glass-fiber reinforced composites

The performance of glass-fiber reinforced composite materials is strongly dependent on adhesion at the fiber-matrix interface. This study has considered the effect of parameters such as wettability, mechanical interlocking due to diffusion, and specific interactions on adhesion. The surface characteristics of treated and untreated glass fibers were studied by inverse gas chromatography. Donor/acceptor concepts were used to calculate a specific (acid/base) interaction parameter for fiber/matrix pairs. Tensile strengths of composites with Nylon-6,6 and polyethylene correlated with both acid-base and dispersive interactions. Initial attempts were made to separate and quantify contributions to interfacial bonding from dispersive forces, acid/base forces, diffusion and the mechanical interlocking of constituents. Findings were supported by scanning electron microscopy of the fracture surfaces of composite samples.