Application of Acoustic Emission Measurements to Investigate Adhesion in Filled Polymeric Composites

Abstract Adhesion in filled polymeric composites is characterized by an acoustic technique in which specimens of the composites are subjected to a ramped uni-axial tensile stress while particle-matrix debonding events are detected acoustically. The maximum in a fitted distribution of debonding events as a function of applied stress is related to the interfacial strength using elasticity theory. Results are reported for different silanetreated and untreated glass and aluminum spheres embedded in a poly(vinyl butyral) matrix. Silane treatment profoundly affects the adhesive strength, with the strongest bonds being formed when acid-base interactions between the particle surface and the matrix polymer are promoted. Significant differences are also found between the aluminum-particle and glass-particle cases, attributable in part to differences in mechanical interlocking. Key Words: Acoustic emissioninterfacial strengthorganofunctional silanesLewis acidbase interactionsmechanical interlocking