Nonisothermal crystallization of poly(Nmethyldodecano-12-lactam) (MPA) was investigated using DSC method at cooling rates of 2-40 K/min. With increasing cooling rate, crystallization exotherms decreased in magnitude and shifted toward lower temperatures. Subsequent heating runs (10 K/min) showed an exotherm just above T-g(,) which increased in magnitude with the rate of preceding cooling run, corresponding to the continuation of primary crystallization interrupted as the system crossed T-g on cooling. Kinetic evaluation by the Avrami method gave values of exponent n close to 2.0, suggesting two-dimensional crystal growth combined with heterogeneous nucleation. The Tobin method, covering the intermediate range of relative crystal-linities, provided n congruent to 2.20, suggesting possible partial in-volvement of homogeneous nucleation at later stages of nonisothermal crystallization. The crystallization rate parameter k(1/n) showed a linear dependency on cooling rate for both methods, the Tobin values being slightly higher. The Ozawa approach failed to provide reasonable values of the kinetic exponent m of MPA. The Augis-Bennet method was used to determine the effective activation energy of the entire nonisothermal crystallization process of MPA. (C) 2004 Wiley Periodicals, Inc.