Projecting long-term non-Fickian diffusion behavior in polymeric composites based on short-term data: a 5-year validation study

Landon R. Grace

Research output: Contribution to journalArticle

9 Scopus citations


The slow approach to equilibrium concentration indicative of non-Fickian diffusion in polymer composites necessitates experimental time frames which are often of limited feasibility. As a result, experimental studies are terminated prematurely due to time constraints or incorrect identification of equilibrium. Here, the three-dimensional anisotropic diffusion behaviors of six-, twelve-, and forty-ply quartz-reinforced bismaleimide laminates are quantified through a 5-year, full-immersion gravimetric absorption study. The applicability of the three-dimensional hindered diffusion model is investigated, while projections of future absorption behavior made at 21 months are revisited in light of 3 years of additional data. The mathematical equivalency of the hindered diffusion model and a diffusion–relaxation model under certain conditions is discussed. Moisture content rises continuously throughout the 5-year experiment for all samples. In the six-ply case, the standard termination criterion for the equilibrium condition is met before 6 months and 1.38 % moisture content by weight. Actual moisture content reaches 1.56 % after 5 years. The hindered diffusion model and associated forward projections of moisture content are found to conform well to experimental results.

Original languageEnglish (US)
Pages (from-to)845-853
Number of pages9
JournalJournal of Materials Science
Issue number2
StatePublished - Jan 1 2016



  • Bismaleimide
  • Hindered diffusion
  • Laminate
  • Moisture absorption

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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