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Title: Heterogeneous Directional Mobility in the Early Stages of Polymer Crystallization

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.2813896· OSTI ID:947247

Recently we demonstrated via large large-scale molecular dynamics simulations a 'coexistence period' in polymer melt ordering before crystallization, where nucleation and growth mechanisms coexist with a phase phase-separation mechanism. Here we present an extension of this work, where we analyze the directional displacements as a measure of the mobility of monomers as they order during crystallization over more than 100 ns of simulation time. It is found that the polymer melt, after quenching, rapidly separates into many ordered hexagonal domains separated by amorphous regions, where surprisingly, the magnitude of the monomer's displacement in the ordered state, parallel to the domain axial direction, is similar to its magnitude in the melt. T. The monomer he displacements in the domain's lateral direction are found to decrease during the time of the simulation. The ordered hexagonal domains do not align into uniform lamellar structures during the timescales of our simulations.

Research Organization:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
947247
Report Number(s):
LLNL-JRNL-408396; JCPSA6; TRN: US200909%%134
Journal Information:
Journal of Chemical Physics, Vol. 128, Issue 1; ISSN 0021-9606
Country of Publication:
United States
Language:
English

References (30)

An approach to the formation and growth of new phases with application to polymer crystallization: effect of finite size, metastability, and Ostwald's rule of stages journal May 1994
Computer "Experiments" on Classical Fluids. I. Thermodynamical Properties of Lennard-Jones Molecules journal July 1967
Relaxation processes in crystalline polymers: experimental behaviour — a review journal March 1985
Ultrafast crystallization of polar polymer melts journal February 2003
Small-angle neutron scattering from star-branched polymers in the molten state journal March 1989
Conformational Characteristics of Poly(tetrafluoroethylene) Chains Based upon ab Initio Electronic Structure Calculations on Model Molecules journal June 1994
Molecular dynamics modeling of polymer crystallization from the melt journal February 2004
Hoover NPT dynamics for systems varying in shape and size journal February 1993
Role of mobile phases in the crystallization of polyethylene. Part 1. Metastability and lateral growth journal November 1991
Formation of Chain-Folded Structures in Supercooled Polymer Melts Examined by MD Simulations journal February 2002
DREIDING: a generic force field for molecular simulations journal December 1990
Formation of Polymer Crystals with Folded Chains from Dilute Solution journal December 1959
Fast Parallel Algorithms for Short-Range Molecular Dynamics journal March 1995
Statistical mechanics of chain molecules journal November 1969
Evidence of Early Stage Precursors of Polymer Crystals by Dielectric Spectroscopy journal January 2007
Polymer crystallization from the metastable melt: The formation mechanism of spherulites journal July 2006
Chain conformation in the induction period of crystallization of poly(ethylene terephthalate) journal August 1995
From the melt via mesomorphic and granular crystalline layers to lamellar crystallites: A major route followed in polymer crystallization? journal October 2000
The role of the torsional potential in relaxation dynamics: a molecular dynamics study of polyethylene journal January 1998
Chain diffusion between crystalline and amorphous regions in polyethylene detected by 2D exchange carbon-13 NMR journal September 1991
Topological Mechanism of Polymer Nucleation and Growth – The Role of Chain Sliding Diffusion and Entanglement book October 2005
Atomistic simulations of spinodal phase separation preceding polymer crystallization journal December 2005
Unified theory of nucleation of folded-chain crystals and extended-chain crystals of linear-chain polymers journal July 1987
Liquid crystalline phase transition of a semiflexible polymer: acetoxypropyl cellulose journal September 1985
An optimized united atom model for simulations of polymethylene melts journal July 1995
A unified formulation of the constant temperature molecular dynamics methods journal July 1984
Molecular Dynamics Simulation of Polymer Crystallization from the Melt journal January 2003
Modeling Polymer Crystallization book October 2005
Spinodal-Assisted Crystallization in Polymer Melts journal July 1998
Molecular Mechanisms of Polymer Crystallization from Solution journal November 2001