Morphological, mechanical and fracture properties of materials based in modified divinylester resins (DVER)

SCHROEDER, WALTER F.; ARANGUREN, MIRTA I.; BORRAJO, JULIO

Foz de Iguaçu, Brasil

Congreso; 3rd Brazil MRS Meeting; 2004

October 10-13, 2004, Anales del Congreso: pág. 308 (poster) The improvement of properties of a thermoset by the addition of a thermoplastic is one of the reasons of the great importance of thermoset-thermoplastic blends. The final properties of the obtained materials are related to their morphologies generated during the polymerization, usually by a reaction-induced phase separation mechanism. The objective of this work is to evaluate the mechanical and fracture properties of poly(methylmetacrylate) (PMMA) modified DVER/styrene (S) thermosets and to relate them with the morphologies developed in the obtained materials. Two DVER were used in this study; a low molecular weight resin synthesized in our laboratory (Mn=600 g/mol), and a commercial resin of higher molecular weight (2100 g/mol). S-DVER mixtures with different proportions of S: 20, 45, 70 % by wt. were prepared; and modified with different contents of PMMA from 0 to 20 % by wt. The mechanical properties of the obtained materials were determined using an Instron Universal Testing Machine in compression and three-point bending tests. The fracture mechanics measurements were made at room temperature, using three-point bending geometry on the same Testing Machine. The addition of a thermoplastic modifier allowed to improve the fracture resistance without the unwanted reduction in modulus, which is inevitable when using elastomeric additives.