Relationship between morphology and solvent interactions of a polyester composite material

A special morphology is shown by injected parts of polyester bulk molding compounds (BMC): a skin with thickness 100 nm, is made of polyester-styrene polymer; the fillers and glass fibers are located in the core of the material; the matrix is composed of a nodular phase of polyester-styrene embedded in a continous phase of low profile additive poly(vinylacetate). The low profile mechanism of the matrix is induced by the formation of microcracks and/or microvoids at the interface of the two phases and in the thermoplastic phase. This work shows that the global chemical composition is independent of the compound flow length but the microvoid concentration is not. These microvoids strongly influence the interactions with organic solvents: diffusion and equilibrium concentration are higher in porous areas. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.