THE EFFECT OF MARINE-ENVIRONMENT ON A VINYL-ESTER RESIN AND ITS HIGHLY FILLED PARTICULATE QUARTZ COMPOSITES

The accelerated effects of immersion in seawater at 60 degrees C, in c omparison to distilled water, on a vinyl ester resin and on its highly quartz particles filled system were studied. The studied resin was cu red at room temperature for 48 h and postcured at 100 degrees C for 12 h, and the filled system contained 93 wt % quartz particles of a wide size distribution, either as received or silane-treated. The immersio n in water results mainly in further curing and some extraction of low molecular substances, as reflected by the flexural mechanical propert ies and the DSC thermograms. The silane coupling agent treatment of th e filler significantly improves che composite properties and its resis tance to the water environment. No practical difference was observed i n any of the studied systems between the effects of sea and distilled water, as tested by the immersion in boiling water for 48 h. Weatherom eter conditions, cycles of ultraviolet radiation at 60 degrees C and w ater condensate at 50 degrees C, for up to 1000 h, also cause postcuri ng effects, without extractables' leaching effects. (C) 1998 John Wile y & Sons, Inc.