Accession Number : ADA290526

Title :   Processing Studies on In Situ Composites Based on Blends of Thermotropic Liquid Crystalline Polymers with Thermoplastics.

Descriptive Note : Final rept.,

Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF CHEMICAL ENGINEER ING

Personal Author(s) : Baird, Donald G.

PDF Url : ADA290526

Report Date : 22 SEP 1994

Pagination or Media Count : 12

Abstract : The purpose of this work was to optimize the reinforcing effect provided by liquid crystalline polymers (LCP) when combined with thermoplastics. The first phase of the research was concerned with the generation of in situ composites in which the LCP fibrils are directly generated during processing. Because the formation of in situ composites requires extensional deformation, the fibrils are highly oriented in one direction leading to materials with highly anisotropic mechanical properties. Methods for reducing the mechanical anisotropy of in situ composites were studied next. The desire to reduce the mechanical anisotropy lead to pregeneration of LCP fibrils using a novel dual extrusion technique developed in our laboratory. The materials containing the pregenerated microfibrils, referred to as micro composites, were then processed at temperatures where the LCP fibrils were not melted. The mechanical anisotropy of injection molded microcomposites were reduced. Further details of the work carried out in this research are given below. First, the research concerned with the in situ composites is discussed. This is followed by a discussion of the process for generating the microcomposites. Finally the processing studies on the microcomposites is presented. (jg)

Descriptors :   *POLYMERS, *COMPOSITE MATERIALS, *LIQUID CRYSTALS, *THERMOPLASTIC RESINS, MECHANICAL PROPERTIES, PROCESSING, DEFORMATION, EXTRUSION, ANISOTROPY, REINFORCING MATERIALS, INJECTION MOLDING.

Subject Categories : Polymer Chemistry
      Physical Chemistry
      Plastics
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE