The Effect of Deformation History on the Morphology of Blends of Polycarbonate and a Thermotropic Liquid Crystalline Polymer

Abstract

The addition of an immiscible liquid crystalline polymer (LCP) to polycarbonate improved its melt processibility. In addition, when a suitable deformation history was employed, the LCP phase was elongated and oriented such that a microfibrillar morphology was retained in the solid state mixture. This has important ramifications for the development of self reinforcing polymer blends to compete with conventional fiber reinforced plastics. Shear flows are generally ineffective at developing these morphologies, but flows that incorporate extensional stresses, such as the converging flow at the entrance to a capillary or die can produce an elongated phase. Single extension flows, such as in melt drawing operations, are most effective at producing LCP microfibrils, and their efficiency increases with increasing draw ratio. The moduli of highly drawn blends were well approximated by a composite analogy of long uniaxially aligned LCP fibers in a polycarbonate matrix.

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Document Details

Document Type
Technical Report
Publication Date
Dec 29, 1988
Accession Number
ADA203061

Entities

People

  • A. Kohli
  • N. Chung
  • Robert A Weiss

Organizations

  • University of Connecticut

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Aspect Ratio
  • Chemical Engineering
  • Chemistry
  • Copolymers
  • Fiber Reinforced Polymers
  • Fibers
  • Glass Transition Temperature
  • Materials Laboratories
  • Materials Processing
  • Materials Science
  • Measurement
  • Military Research
  • Plastics
  • Reinforced Plastics
  • Shear Flow
  • Thermoplastic Resins
  • Transition Temperature

Fields of Study

  • Materials science

Readers

  • Fluid Dynamics.
  • Polymer Science and Engineering.
  • Reinforced Composite Materials