Final Microstructure Analysis of Styrene Crosslinked Vinylester and Unsaturated Polyester Resin Thermosets

M. A. MOSIEWICKI; F. L. LEITE; P. S. P. HERRMANN; A. A. S. CURVELO; W. F. SCHROEDER; M. I. ARANGUREN; J. BORRAJO

Florianópolis, Brasil

Simposio; 1st French-Brazilian Meeting on Polymers; 2005

Universidad Federal de Santa Catarina (UFSC), Laboratoire de Chimie des Polymères Organiques (LCPO).

There is a great scientific and technological interest in the study and understanding of the structure and properties of styrene (St) cross-linked vinylester (VE) and unsaturated polyester (UP) resins, because they are widely used as matrices in composites, sharing advantages, such as low room temperature viscosity coupled with well mechanical properties and low cost, plus the added chemical resistance in the case of VE.  The cross-linked reaction occurs by free radical polymerisation where long-chain molecules are formed through connecting St monomers and resin molecules by both inter- and intramolecular reactions. These long-chain molecules tend to form a spherical type of structure or “nanogel particle”, due to the intramolecular cross-linking among the pendant C=C bonds of molecules [1].  The microgel morphologies are strongly depending of the cure temperature and the initial composition of the reactive mixture as was previously reported [1,2]. The aim of this work is to study the relationship between the final morphologies and St/resin initial ratio, and to compare the development microstructures with the use of two different resins.