Crystallization kinetics of β‐phase poly(propylene)

Crystal growth rates of spherulites of β‐phase poly(propylene)s and of an ethylene/propene block copolymer, crystallized from the melt, have been investigated in the temperature range of 122 to 146°C. On the basis of the regime theory, a transition between regime II and III is found at ΔT ≈ 37–43,5 K. The nucleation constant for β‐phase poly(propylene)based on the current theory of crystal growth was determined, and the fold surface free energy of β‐phase poly(propylene) was estimated from the nucleation constant for different samples to lie between 48,2 and 55,2 erg/cm2 (1 erg = 10−7 J).