The Fracture Toughness of Epoxy-Glass Bead Composites

Abstract

The plane strain fracture toughness of epoxy resins and glass bead filled epoxy composites has been investigated. Primary parameters were curing agent concentration, filler concentration, adhesion of filler to polymer, temperature, and water immersion. Fracture toughness was measured using double edge notched specimens and tensile strength and Young's modulus were measured using standard ASTM tensile bars. Scanning electron microscopy was used to examine the fracture surfaces. It was found that the energy required for fracture depended primarily on the ability to dissipate energy in the polymer phase. At higher temperatures and/or increased catalyst concentration, the unfilled epoxy became more ductile, its fracture surface became rougher, and its fracture energy was increased. At lower temperatures, where the epoxy was relatively brittle, the addition of glass beads increased the fracture energy and induced roughness in the otherwise smooth fracture surface. When the epoxy was ductile, the addition of beads tended to decrease the fracture energy. The reduction of fracture energy for the ductile polymer was attributed to the reduction of the amount of polymer surface created.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1971
Accession Number
AD0880428

Entities

People

  • A. D. Wambach
  • A. T. Dibenedetto

Organizations

  • Monsanto

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Adhesion
  • Composite Materials
  • Contracts
  • Curing Agents
  • Ductility
  • Electron Microscopy
  • Epoxy Composites
  • Materials
  • Mechanical Properties
  • Microscopy
  • Modulus Of Elasticity
  • Physical Properties
  • Polymers
  • Roughness
  • Surface Finishing
  • Tensile Strength
  • Toughness

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
  • Reinforced Composite Materials
  • Surface Coatings Technology.

Technology Areas

  • Microelectronics