Effect of Interface Adhesion on the Spall Strength of Particle-Reinforced Polymer Matrix Composites

Prior research investigating the spall strength in metal alloys has shown that the presence of secondary phase intermetallics can be a source of spall nucleation. In polymer composites with a reinforcing phase, the particle surfaces can be functionalized to improve the surface adhesion between the matrix and filler at the interface, which has been shown to improve the quasi-static strengths of the materials. In the present study, we apply silanes to modify the surface chemistry of micron-sized alumina particles to tailor interface adhesion between the alumina filler and an elastomer matrix Sylgard 184. Two silanes were selected to both increase and decrease interface adhesion respectively to further observe the significance of interface adhesion on dynamic tensile strength. The composites were characterized through spall experiments using a single stage light gas gun at Carleton University. It was found that composites with impeded adhesion showed a drastic reduction in spall strength associated with a loss of adhesion at the interface.