Abstract: To explore the polymerization system suitable for vacuum infusion anionic polyamide-6(APA-6), the conversion-time relations of different activator-initiator combinations for APA-6 were investigated. Accor-ding to the conversion-time relations during the reaction, it indirectly reflected the viscosity-time relations. The results show that the systems of C10/C20(100℃) and C10/TDI are desired for vacuum infusion of anionic polyamide-6 composites, because both of them show slow linear conversion increase at the beginning of the reaction. However, after a while, the polymerization rate increased rapidly and that the degree of conversion increased exponentially in time. On the basis of the previous research, the reason that the systems of C10/TDI was more suitable for manufacturing thicker, lager and more complicated textile fiber reinforced thermoplastic composites were discussed using differential scanning calorimeter(DSC) thermal analysis from the mechanism of the generation of active center. In addition, compared with traditional nylon 6, the degree of crystallinity, modulus and the temperature of glass transition(T_g) of vacuum infusion APA-6 exhibit remarkably improved. And there are also different properties between two kinds of ideal system of anionic polyamide-6 for vacuum infusion process, the reason was preliminary discussed from mechanisms of blocking and de-blocking of the activator.

Key words: Anionic polyamide-6, Vacuum infusion process, Polymerization system, Degree of conversion