Application of acoustic emission measurements to investigate adhesion in filled polymeric composites

Adhesion in filled polymeric composites is characterized by an acoustic tec hnique in which specimens of the composites are subjected to a ramped uni-a xial tensile stress while particle-matrix debonding events are detected aco ustically. The maximum in a fitted distribution of debonding events as a fu nction of applied stress is related to the interfacial strength using elast icity theory. Results are reported for different silane-treated and untreat ed glass and aluminum spheres embedded in a poly(vinyl butyral) matrix. Sil ane 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 foun d between the aluminum-particle and glass-particle cases, attributable in p art to differences in mechanical interlocking.