Chemical ageing of linseed oil based thermosets

MIRNA MOSIEWICKI; OSCAR ROJAS; MARÍA R. SIBAJA; JULIO BORRAJO; MIRTA I. ARANGUREN

Rio de Janeiro, Brasil

Congreso; Word Polymer Congress (Macro 2006); 2006

Associacao Brasileira de Polímeros

Rigid thermosetting polymers prepared by free radical polymerization of styrene with linseed oil based resins, were evaluate under different environmental conditions and at different times after their preparation. The oxygen in the environment is enough to produce chemical changes in these polymers affecting the properties of the cured materials. These changes have been analyzed by mechanical and dynamical-mechanical tests. An increase of the modulus with the time was observed after exposing the samples to dry conditions, or humid environments with 60% relative humidity, or with additional UV radiation. Acceleration of the polymerization reactions occurs when the materials are subjected to UV radiation. In particular, a large effect on the glass transition temperature is observed after a few hours of exposition.