Dielectric Relaxation Spectroscopy of Adhesively Bonded Joints

Abstract

Molecular aspects of chemical and physical changes in adhesively bonded joints caused by absorbed moisture were investigated. The focus was on the pre-damage stage that precedes the formation of voids and microcracks. Dielectric relaxation spectroscopy was used as a non-destructive tool to characterize he molecular level changes in the adhesive when exposed to hygrothermal environments. Three adhesive types, a commercial epoxy-amine formulation (FM73U), a model epoxy formulation consisting of diglycidyl ether of Bisphenol A (DGEBA) and methylene dianiline (MDA), and a bismaleimide formulation consisting of 4,4' bismaleimidodiphenyl methane (component A) and 0,0' diallyl bisphenol (component B) were studied. Local dynamics were monitored by broad-band dielectric relaxation spectroscopy (DRS) and the changes in the chemical state of the matter were monitored by FTIR. The influence of moisture on the strength and durability of adhesively bonded joints were also investigated.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2001
Accession Number
ADA398090

Entities

People

  • Jovan Mijovic
  • Mohan Balan
  • Patricia Stumpff
  • Rajesh K. Tiwari
  • Som R. Soni

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Adhesives
  • Bonded Joints
  • Chemical Reactions
  • Chemical Synthesis
  • Chemistry
  • Environment
  • Finite Element Analysis
  • Materials
  • Mechanical Properties
  • Molecular Dynamics
  • Physical Properties
  • Regression Analysis
  • Resilience
  • Spectra
  • Spectroscopy
  • Three Dimensional
  • Two Dimensional

Fields of Study

  • Materials science

Readers

  • Molecular Photonics/Laser Physics
  • Polymer Science and Engineering.
  • Structural Health Monitoring of Composite Structures.