Tailored polyethylene nanocomposite sealants: Broad-range peelable heat-seals through designed filler/polymer interfaces

Jinguo Zhang, Evangelos Manias, George Polizos, Jin Young Huh, Amos Ophir, Ponusa Songtipya, Maria Del Mar Jimenez-Gasco

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

The heat sealing behavior of novel polyethylene-based nanocomposite films was investigated, as they relate to flexible packaging of fresh-cut vegetables, processed foods and biomedical devices. Appropriately designed sealant nanocomposites, which include dispersed montmorillonite nanofillers and ethyl vinyl acetate copolymer, produce a hermetic but peelable heat seal across a broad, 30-40°C, range of heat sealing temperatures, outperforming optimized commercial polyethylene-based sealants that achieve peelable seals in a much narrower heat sealing temperature range, of less than 15°C. Appropriate nanocomposite design leads to a general easy-open/peelable character of heat seals, which is: (a) independent of sealing conditions and apparatus - ranging from long dwell times at very high sealing pressures to very short heat impulses at very low sealing pressures; (b) markedly independent of the opposite side of the heat seal - for example, when sealed on itself, on unfilled sealant, or on high density polyethylene; and (c) rather insensitive to formulation variations of the sealant - for example, variations of the polyethylene of the ethyl vinyl acetate type and concentration, and of nanofiller loading. Insights from observations of the fracture seal surfaces by infrared spectroscopy and electron microscopy reveal that the underlying mechanism of this behavior is related to a synergistic effect of the ethyl vinyl acetate copolymer and the montmorillonite clay nanofiller, which introduces weak interfaces in the nanocomposite that lead to cohesive failure of the sealant.

Original languageEnglish (US)
Pages (from-to)709-737
Number of pages29
JournalJournal of Adhesion Science and Technology
Volume23
Issue number5
DOIs
StatePublished - Jul 1 2009

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All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Mechanics of Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

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