Dual Nakamura model for primary and secondary crystallization applied to nonisothermal crystallization of poly(ether ether ketone)

Non-isothermal crystallization kinetics has been traditionally predicted using the Nakamura crystal growth model, which is an integral form of Avrami equation under assumption that non-isothermal can be explained a series infinitesimal isothermal steps. However, model often overpredicts fraction near end because ignoring slower secondary kinetics. In this study, dual proposed to capture both primary and poly(ether ether ketone) (PEEK). First, PEEK monitored at five constant cooling rates 10, 30, 50, 70, 90 K/min via differential scanning calorimetry. The contains smaller exponent ( n s ) account for crystallization, fitted exothermal heat flow curves. successfully describes final stage all by reducing dimension from p = 3 ≅ 1.