INFLUENCE OF MICROSTRUCTURE ON DYNAMIC MECHANICAL-BEHAVIOR OF POLYMERIC COMPOSITES WITH COMPLEX INCLUSIONS

Abstract

The dynamic mechanical properties of polymeric composites composed of crosslinked poly (n-butyl methacrylate) continuous-phase and crosslinked polystyrene dispersed phase with poly (n-butyl methacrylate) occlusion have been examined. The composite samples were prepared by mixing and swelling of the crosslinked polystyrene particles obtained by emulsifier-free emulsion polymerization, with n-butyl methacrylate and crosslinker, then photopolymerizing at the desired temperature. The composite microstructure was varied by either changing the crosslink density of polystyrene, and temperature of swelling and polymerization, or using different sizes and contents of polystyrene particles. The tan delta peak positions of composite samples are found to be dependent on morphological characteristics as well as the properties of the dispersed phase while the peak height seems to be dependent on the effective volume of dispersed phase composed of polystyrene and poly (n-butyl methacrylate) occlusions. Special attention has been paid to the comparison among composite, homonetworks, and bulk IPN samples that are expected to have the identical structure with the complex dispersed phase of the composite samples.