RELATIONSHIP BETWEEN MORPHOLOGY AND SOLVENT INTERACTIONS OF A POLYESTER COMPOSITE-MATERIAL

A special morphology is shown by injected parts of polyester bulk mold ing compounds (BMC): a skin with thickness 100 nm, is made of polyeste r-styrene polymer; the fillers and glass fibers are located in the cor e of the material; the matrix is composed of a nodular phase of polyes ter-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 g lobal chemical composition is independent of the compound flow length but the microvoid concentration is not. These microvoids strongly infl uence the interactions with organic solvents: diffusion and equilibriu m concentration are higher in porous areas. (C) 1998 Published by Else vier Science Ltd. All rights reserved.