The processability of prepregs lacks quantitative characterization methods. By studying the rheological properties and the glass transition temperatures of 4 typical epoxy resins and their C/E prepregs’ processability, it proved that the subjective notion of the tack property of prepregs can be characterized objectively by two physical properties:the η* and the T_g. It is shown that epoxy resins with T_g=0℃ or η*=35 kPa瘙
簚s yield optimum tack properties for prepregs.