VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG
Carboxyl functional polyarylene 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 Tgs, Tms 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.
This article is from 'Multifunctional Materials Held in Boston, Massachusetts on November 29-December 1 1989. Materials Research Society Symposium Proceedings. Volume 175,' AD-A253 089, p351-356.