Annealing studies on a fully cured epoxy resin: Effect of thermal prehistory, and time and temperature of physical annealing

Abstract

SynopsisThe dynamic mechanical behavior at about 1 Hz of a fully cured epoxy resin (maximum glass transition temperature, T , , , ca. 170°C) has been studied during and after isothermal annealing in terms of the influence of thermal prehistory, time of annealing, and temperature of annealing ( T,). Annealing temperatures ranged from Tg -15 to Tg -130°C. The rate of isothermal annealing was observed to decrease by a decade for each decade increase of annealing time when the material was far from equilibrium. Annealing at high temperatures did not measurably affect the material properties during cooling (for T < < T,); similarly the effect of annealing at low temperatures was not measurable during heating (for T > > T,).

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