Investigation of the polycarbonate/crushed-rubber-particle interphase by nanoindentation

Nanoindentation tests were carried out to determine the nanomechanical characteristics of recycled polycarbonate (PC)/crushed-rubber blends. Both the modulus and hardness of the matrix, particles, and PC/rubber interphase were obtained. Different blends with untreated, flamed, and washed rubber particles were characterized. The results proved the good recyclability of PC. Indentations performed in the PC matrix showed that the rubber acted as a plasticizer for the PC matrix, probably because of a diffusion of free rubber chains. This plasticizing effect was accentuated by flamed rubber particles in the blends. The results showed that flame and methanol treatments modified the morphology of the rubber particles. These treatments induced a significant increase in the nanomechanical properties of the rubber particles. In the interface region between the PC matrix and rubber particles, a gradual change in the mechanical properties was confirmed. Profiles of the interface modulus and hardness helped to determine the interface width according to the particle treatment. (c) 2006 Wiley Periodicals, Inc.