Deformation and Fracture Behavior of Molecular Composites via Ionic Interactions.

Abstract

Melt-processable molecular composites have been developed and their mechanical behavior has been investigated. In these composites, rigid-rod molecules, which serve as a reinforcer, are well dispersed in a flexible-coil matrix polymer due to strong ionic interactions between the components. In this new type of composite material, mechanical properties are effectively enhanced by a very small addition (several %) of reinforcers. As a reinforcer, we have prepared PPTA (or Kevlar) with various ionic groups, ion content, and counterions. The mechanical behavior of molecular composites made from an amorphous polymer is unique in that not only stiffness and strength but ductility is enhanced. This is because crazing is suppressed in favor of shear deformation due to molecular level interactions between ionic rod and coil molecules; a condition not seen for conventional macro-fiber composites. The mechanical behavior of molecular composites made from a ductile, crystalline polymer indicates that both stiffness and strength can be significantly enhanced without losing toughness upon small addition of ionic Kevlar (only several %). A most dramatic change in mechanical properties is seen for the composite made from a soft, rubbery matrix polymer. Since strong/stiff reinforcing molecules (ionic Kevlar) are dispersed, very effective reinforcement is achieved.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1996
Accession Number
ADA318476

Entities

People

  • Masanori Hara

Organizations

  • Rutgers University–New Brunswick

Tags

Communities of Interest

  • Human Systems

DTIC Thesaurus Topics

  • Alkenes
  • Biomedical And Dental Materials
  • Chemistry
  • Composite Materials
  • Dielectric Polymers
  • Engineering
  • Macromolecules
  • Materials
  • Materials Science
  • Mechanical Properties
  • Mechanics
  • Military Research
  • Molecules
  • Polymers
  • Stiffness
  • Thermoplastic Resins
  • Toughness

Fields of Study

  • Materials science

Readers

  • Polymer Science and Technology
  • Powder metallurgy of Titanium alloys.
  • Reinforced Composite Materials