Novel crystallization kinetics modeling of advanced polymer composites

We have demonstrated that the dual-stage crystallization model is suitable for analyzing semi-crystalline polymers, particularly in the area of advanced composite processing. This model gives a superior numerical fit than the conventional Avrami approach and perhaps reveals some physical meanings for the parameters. For the chosen polymers: PEEK, PEKK and PPS, the estimated primary crystallinity (volume percentage) is in the range of 0.6-0.7 providing a good numerical fit and may be close to the real value. The primary rate constant decreases with increases in temperature, indicating that the nucleation growth rate decreases at high temperatures. Finally, we have observed that carbon fiber has a minimal effect on the total crystallization of composites, at least for the case of AS-4/PEKK. This may be attributed to the intrinsically high nucleating ability of PEKK.