Accession Number : ADA318476

Title :   Deformation and Fracture Behavior of Molecular Composites via Ionic Interactions.

Descriptive Note : Final rept. 1 Apr 93-31 Jul 96,

Corporate Author : RUTGERS - THE STATE UNIV NEW BRUNSWICK NJ DEPT OF MECHANICS AND MATERIALS SC IENCE

Personal Author(s) : Hara, Masanori

PDF Url : ADA318476

Report Date : OCT 1996

Pagination or Media Count : 7

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.

Descriptors :   *IONS, *MOLECULES, *COMPOSITE MATERIALS, *DEFORMATION, *FRACTURE(MECHANICS), SHEAR PROPERTIES, COILS, MECHANICAL PROPERTIES, MOLECULAR STATES, INTERACTIONS, POLYMERS, PROCESSING, STIFFNESS, MELTS, TOUGHNESS, AMORPHOUS MATERIALS, CRYSTALS, MOLECULE MOLECULE INTERACTIONS, DUCTILITY, RIGIDITY, REINFORCING MATERIALS, CRAZING.

Subject Categories : Polymer Chemistry
      Laminates and Composite Materials
      Atomic and Molecular Physics and Spectroscopy
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE