Polymer crystal-melt interfaces and nucleation in polyethylene

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

Kinetic barriers cause polymers to crystallize incompletely, into nanoscale lamellae interleaved with amorphous regions. As a result, crystalline polymers are full of crystal-melt interfaces, which dominate their physical properties. The longstanding theoretical challenge to understand these interfaces has new relevance, because of accumulating evidence that polymer crystals often nucleate via a metastable, partially ordered "rotator" phase. To test this idea requires a theory of the bulk and interfacial free energies of the critical nucleus. We present a new approach to the crystal-melt interface, which represents the amorphous region as a grafted brush of loops in a self-consistent pressure field. We combine this theory with estimates of bulk free energy differences, to calculate nucleation barriers and rates via rotator versus crystal nuclei for polyethylene. We find rotator-phase nucleation is indeed favored throughout the temperature range where nucleation is observed. Our methods can be extended to other polymers.

Original languageEnglish (US)
Pages (from-to)2909-2917
Number of pages9
JournalSoft Matter
Volume7
Issue number6
DOIs
StatePublished - Mar 21 2011

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Polyethylene
polyethylenes
Polymers
Nucleation
nucleation
Crystals
polymers
Free energy
crystals
free energy
nuclei
brushes
Brushes
lamella
pressure distribution
Physical properties
physical properties
Crystalline materials
Kinetics
causes

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Condensed Matter Physics

Cite this

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Polymer crystal-melt interfaces and nucleation in polyethylene. / Milner, Scott Thomas.

In: Soft Matter, Vol. 7, No. 6, 21.03.2011, p. 2909-2917.

Research output: Contribution to journalArticle

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