Morphogenesis of lamellar polymer crystals
Institut de Chimie des Surfaces et Interfaces, CNRS
15, rue Jean Starcky, B.P. 2488, 68057 Mulhouse Cedex, France
Accepted: 21 September 2001
Using a previously developed simulation model we study the changes in morphology of two-dimensional chain crystals caused by annealing. A series of various intermediate crystalline states with different stability exhibiting a non-monotonous evolution of the internal energy and the degree of local order was found. This clearly shows the generic non-equilibrium character of polymer crystals. Thus, the classification scheme of equilibrium thermodynamic phases cannot be used to describe such transient states in polymer crystals. At large length scales the structural changes resemble a liquid-like behaviour while at the same time at small length scales the chains show an improvement of crystalline order. The term morphogenesis reflects this complex kinetic behaviour. In addition, simulations with constant heating rates also demonstrate the importance of relaxation processes in polymer crystals.
PACS: 81.10.Aj – Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation / 61.41.+e – Polymers, elastomers, and plastics / 68.55.-a – Thin-film structure and morphology
© EDP Sciences, 2001