A General Approach for Estimating Lamella-Thickness Distribution in Polymers with Low-Frequency Raman Spectroscopy: Application to Lamella Formation in Crystallizing Polyethylene

Ashok Zachariah Samuel, Hiro o. Hamaguchi

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A general method for estimating lamella-thickness distribution in semicrystalline polymers has been developed and applied to polyethylene (PE). The longitudinal acoustic mode (LAM) of PE appears at very low frequencies (i.e., (Formula presented.) 8–20 cm−1) in the Raman spectrum. It represents a distribution of lamellae of varying thicknesses. We propose a distribution function that converts a low-frequency LAM Raman band into the corresponding lamellae-thickness distribution. By using this distribution function, we can study lamella formation in crystallizing PE to elucidate the influence of supercooling and determine critical lamella thickness, the minimum chain length at which folding occurs, and the associated thermodynamic parameters accurately. This method has a general applicability toward the examination of polymer crystallization in an accurate and straightforward manner. Understanding the molecular details of polymer crystallization has applications, particularly in polymer thin-film photovoltaics and polymer processing, beyond its fundamental academic significance.

Original languageEnglish
Pages (from-to)9333-9339
Number of pages7
JournalChemistry - A European Journal
Issue number37
Publication statusPublished - 2018 Jul 2
Externally publishedYes



  • chain structures
  • crystal growth
  • lamella thickness
  • polymers
  • Raman spectroscopy

ASJC Scopus subject areas

  • Chemistry(all)

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