BIODEGRADABLE AND BIOCOMPATIBLE INORGANIC-ORGANIC HYBRID MATERIALS - 2 - DYNAMIC-MECHANICAL PROPERTIES, STRUCTURE AND MORPHOLOGY

Dynamic mechanical properties, structure and morphology of tetraethoxy silane/poly(epsilon-caprolactone) (TEOS/PCL) hybrid materials have bee n analysed by dynamic mechanical spectroscopy, small-angle X-ray scatt ering, transmission electron microscopy, and image analysis. The exper imental observations agree with a microscopic phase separation of the two constitutive components: the organic polymer and the silica networ k. The effect of the PCL functional end-groups, the number of function al end-groups per PCL chain, the PCL molecular weight and content, and the curing conditions have been studied on the structure and properti es of the hybrid materials. Finally, phase morphology has proved to be co-continuous, at least when the weight composition is close to 50% f or each component (SiO2 and PCL), with a characteristic length between the PCL and silica phases of ca. 5 nm, as estimated by image analysis of transmission electron micrographs. (C) 1997 Elsevier Science Ltd.