Accession Number : ADP007490
Title : Synthesis of Segmented Anisotropic-Isotropic Poly(Aryl Ester)Poly(Arylene Ether) Copolymers,
Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG
Personal Author(s) : McGrath, J. E. ; Cooper, K. L. ; Waehamad, W. ; Huang, H. ; Wilkes, G. L.
Report Date : FEB 1991
Pagination or Media Count : 6
Abstract : Carboxyl functional poly(arylene ether) oligomers of controlled number average molecular weight were synthesized via nucleophilic aromatic substitution step polymerization using p-hydroxy benzoic acid as the molecular weight and end group controlling reagents. The subsequent functionalized polyarylene ethers were copolymerized with acetoxy benzoic acid or acetoxy-phenoxy benzoic acid via melt acidolysis procedures. Successful copolymers were generated using chlorobenzene as a solvent for the first stage of the reaction followed by melt reaction at temperatures as high as 325 deg C. Resulting copolymer composition and segment size were investigated. it was possible to prepare improved solvent resistant copolymers through incorporation of the liquid crystal polyester (LCP) segment. Extraction tests using boiling chloroform showed that a high percentage of segmented copolymer were generated. Swelling characteristics were also noted and were observed to decrease as a function of the LCP concentration utilized. Multiple transitions were observed in differential scanning calorimetry consistent with Tg's, Tm's and possibly with liquid crystal transitions. optical microscopy showed an ordered microstructure developed which is consistent with the presence of liquid crystalline phases. The materials were successfully compression molded to afford tough coherent films at all compositions, implying the likelihood of improved compressive strength relative to the LCP homo- or copolyesters.
Descriptors : *COMPRESSIVE PROPERTIES, ACIDS, BENZOIC ACIDS, BOILING, CALORIMETRY, CHLOROBENZENE, CHLOROFORM, COMPRESSION, COPOLYMERS, CRYSTALS, ETHERS, EXTRACTION, FILMS, FUNCTIONS, LIQUID CRYSTALS, LIQUIDS, MATERIALS, MELTS, MICROSCOPY, MICROSTRUCTURE, MOLECULAR WEIGHT, NUMBERS, OLIGOMERS, POLYMERIZATION, SCANNING, SEGMENTED, SOLVENTS, TEMPERATURE, TEST AND EVALUATION, TRANSITIONS, WEIGHT.
Subject Categories : Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE