Volume 128, 2005

Molecular dynamics modeling of polymercrystallization; from simple polymers to helical ones


Crystallization of helical polymers is a very big challenge for molecular simulation. It involves many significant issues, such as folding in biomolecules and molecular recognition during crystal growth. Though direct molecular simulations of the process still involve very difficult problems, we here report our recent efforts toward better understanding of the crystallization in helical polymers. We begin with a brief review of our former studies on simple polyethylene-like polymers, and then we introduce several helical polymer models which are systematically made more complicated. We have already reported that a simple polyethylene-like polymer crystallizes very fast into chain folded lamellae from the melt. A slight modification of this simple polymer model by introducing proper bond angle and dihedral angle potentials gives one of the present models of the helical polymer. This helical polymer model is devised to be relatively rigid but mobile, to show easy helix-reversals, and to have a definite preference for gauche bonds. We find that this highly mobile helical polymer shows quick chain folded crystallization and forms approximate 4/1 helical structure. The intra- and the intermolecular order grow quite simultaneously suggesting highly cooperative nature of the phenomena. Further elaboration of the helical model, giving pendant side groups and higher energy barrier to the helix reversals, leads us to a realistic united atom model of iPP. The conventional and the multi-canonical Monte Carlo simulations are applied to find probable modes of chain folding and the ground state conformations. Though a very short chain readily forms a regular 3/1 helix of alternating trans and gauche bonds, much longer chains of 30- and 50-propylene units are not found to have energetic ground states in the regularly folded conformations.

Article information

Article type
22 Apr 2004
14 May 2004
First published
13 Aug 2004

Faraday Discuss., 2005,128, 75-86

Molecular dynamics modeling of polymer crystallization; from simple polymers to helical ones

T. Yamamoto, N. Orimi, N. Urakami and K. Sawada, Faraday Discuss., 2005, 128, 75 DOI: 10.1039/B406069E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity