Accession Number : ADA264834


Title :   Physical Chemical Studies on Molecular Composite Compositions


Descriptive Note : Final rept. 1 Jan 88-31 Jul 92,


Corporate Author : CARNEGIE-MELLON UNIV PITTSBURGH PA


Personal Author(s) : Berry, Guy C


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264834.pdf


Report Date : 20 Feb 1993


Pagination or Media Count : 100


Abstract : Research in three areas is described: nonlinear optical (NLO) properties of nematic solutions of PBT; the refractive indices of nematic solutions of PBT-, and the rheological properties of blends of PBT and nylon-66, or PBO and PabBO, where PBT is trans-poly(1,4-phenylene-2,6-benzobisthia-zole), PBO is cis-poly(1.4-phenylene-2,6-benzobisoxazole), PabBO is poly(2,5- benzoxazole), and nylon-66 is poly(hexamethylene adipamide). Fully aligned monodomains of nematic solutions of PBT were used in the first two parts. An unexpected NLO behavior was observed in which the maximum NLO third-harmonic generation did not occur with light polarized along the molecular axis of the rodlike PBT, even though the refractive index is maximum for that case-possible reasons for this behavior are discussed. The rheology of miscible blends of the rodlike chains with flexible or semiflexible chains is discussed using a model accounting for constraints on the rodlike dynamics imposed by the flexible or semiflexible components. It is shown that information from phase equilibria is essential to such an analysis, as the dynamic constraints are correlated with the factors that cause the formation of the nematic phase in such blends.


Descriptors :   *POLYMERS , *REFRACTIVE INDEX , *NONLINEAR OPTICS , *MOLECULAR STRUCTURE , *RHEOLOGY , OPTICS , POLARIZATION , BLENDING , MODELS , NYLON , MIXTURES , MESOMORPHIC COMPOUNDS , BENZOXAZOLES , AXES , THIRD HARMONIC GENERATION , CHAINS , LIQUID CRYSTALS , PHASE , CRYSTALS , LIGHT , COMPOSITE MATERIALS , CHEMICALS , DYNAMICS , LIQUIDS


Subject Categories : Physical Chemistry
      Polymer Chemistry
      Laminates and Composite Materials
      Optics


Distribution Statement : APPROVED FOR PUBLIC RELEASE