G. Strobl, From the melt via mesomorphic and granular crystalline layers to lamellar crystallites: A major route followed in polymer crystallization?, EUR PHY J E, 3(2), 2000, pp. 165-183
Based on broad and detailed evidence from a large variety of experiments on
several polymer systems carried out by other authors and ourselves, a nove
l concept for understanding the crystallization of polymers from the melt i
s developed. The experiments generally indicate that the formation and grow
th of the lamellar crystallites is a multi-step process passing over interm
ediate states. We suggest a specific route which is compatible with the obs
ervations. It is proposed that the initial step is always the creation of a
mesomorphic layer which spontaneously thickens, up to a critical value, wh
ere it solidifies through a cooperative structural transition. The transiti
on produces a granular crystalline layer, which transforms in the last step
into homogeneous lamellar crystallites. The model leads to predictions abo
ut the temperature dependencies of the crystal thickness and the growth rat
e which are at variance with conventional views but in agreement with findi
ngs in recent experiments.