Temperature dependency of water vapor permeability of shape memory polyurethane

Yue M. Zeng, Jinlian Hu, Hao Jing Yan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

5 Citations (Scopus)

Abstract

Solution-cast films of shape memory polyurethane have been investigated. Differential scanning calorimetry, DMA, tensile test, water vapor permeability and the shape memory effect were carried out to characterize these polyurethane membranes. Samples cast at higher temperatures contained more hard segment in the crystalline state than a sample cast at lower temperature. The change in the water vapor permeability (WQVP) of SMPU films with respect to the temperature follows an S-shaped curve, and increases abruptly at Tm of the soft segment for the fractional free volume (FFV, the ratio of free volume and specific volume in polymers) increased linearly with temperature. The water vapor permeability dependency of the temperature and humidity contribute to the result of the change of diffusion and solubility with the surrounding air condition. The diffusion coefficient (D) are the function of temperature and show good fit the Arrhenius form but show different parameter values when above and below Tg. The crystalline state hard-segment is necessary for the good shape memory effect.
Original languageEnglish
Pages (from-to)52-57
Number of pages6
JournalJournal of Dong Hua University (English Edition)
Volume19
Issue number3
Publication statusPublished - 1 Sep 2002

Keywords

  • Polyurethane
  • Shape memory
  • Temperature dependency
  • Water vapor permeability

ASJC Scopus subject areas

  • Polymers and Plastics

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