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  • 1
    Electronic Resource
    Electronic Resource
    Synthesis, characterization, and properties of colorless rigid-rod poly(benzobisthiazole) derived from bicyclo[2.2.2]octane (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2953-2960 
    Details
    ISSN: 0887-624X
    Keywords: benzobisthiazole ; bicyclo[2.2.2]octane ; rigid-rod ; colorless ; 3-dimensional ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polycondensation in polyphosphoric acid of 2,5-diamino-1,4-benzene dithiol dihydrochloride with bicyclo[2.2.2]octane-1,4-dicarboxylic acid, as well as the corresponding dimethyl ester or diacid chloride, led to rigid-rod benzobisthiazole polymers. Colorless and soluble polymers with intrinsic viscosities as high as 30.6 dL/g (methanesulfonic acid, 30°C) were obtained. The ultraviolet-visible spectrum of a polymer film cast from methanesulfonic acid under reduced pressure displayed no absorptions in the visible range (400-900 °m). The polymer was thermooxidatively stable up to 420°C in air as determined by thermogravimetric analysis. Fibers spun from a lyotropic polyphosphoric acid solution exhibited a tensile strength of 300-450 Ksi, a modulus of 26 Msi, and a compressive strength of 53 Ksi. Wide-angle X-ray scattering patterns of polymer fibers indicated a 3-dimensional crystal structure rather than a nematic liquid crystal structure. © 1994 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1994.080321517
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  • 2
    Electronic Resource
    Electronic Resource
    Multidimensional benzobisoxazole rigid-rod polymers. I. Preparation and characterization (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 3451-3456 
    Details
    ISSN: 0887-624X
    Keywords: PBO ; rigid-rod polymer ; multidimensional polymer ; thermooxiative stability ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two- and three-dimensional rigid-rod polymers containing benzobisoxazole structures were prepared through the polycondensation in polyphosphoric acid of 4-[5-amino-6-hydroxybenzoxazol-2-yl]benzoic acid (ABA) with trimesic acid and 1,3,5,7-tetrakis(4-carboxylatophenyl)adamantane, respectively. Thermal properties of the polymers were determined by differential scanning calorimetry, thermogravimetric/mass spectral analysis, and isothermal aging studies. The multidimensional polymers exhibited lower solution viscosities and lower thermooxidative stabilities than the one-dimensional polymer generated by the homopolymerization of ABA under identical reaction conditions. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3451-3456, 1997
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Multidimensional benzobisoxazole rigid-rod polymers. II. Processing, characterization, and morphology (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 3457-3466 
    Details
    ISSN: 0887-624X
    Keywords: PBO ; rigid-rod polymer ; multidimensional polymer ; compressive strength ; fiber morphology ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A high-torque rheometer was used to facilitate the polycondensation of 4-[5-amino-6-hydroxybenzoxazol-2-yl]benzoic acid (ABA) with trimesic acid and 1,3,5,7-tetrakis(4-carboxylatophenyl)adamantane to yield two- and three-dimensional benzobisoxazole polymers, respectively. Although the resultant polymer dopes exhibited improved homogeneity compared to polymer dopes previously prepared in glassware, improved polymer solution viscosities were not achieved. Fibers spun from the two- and three-dimensional polymers did not show a significant increase in compressive strength compared to fibers of the linear or one-dimensional benzobisoxazole polymer derived from the homopolymerization of ABA. Morphological studies of the polymer fibers and films by wide-angle X-ray scattering and scanning electron microscopy strongly indicated more lateral disorder and a more isotropic character for the three-dimensional structures compared to the one-dimensional structures. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3457-3466, 1997
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Synthesis, processing, and third-order nonlinear optical properties of benzobisthiazole polymers containing thiophene moieties (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 723-729 
    Details
    ISSN: 0887-624X
    Keywords: benzobisthiazole ; nonlinear optical ; thiophene ; degenerate four-wave mixing ; bithiophene ; terthiophene ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Benzobisthiazole polymers containing mono-, bi-, and terthiophene moieties were synthesized through polycondensation in polyphosphoric acid of 2,5-diamino-1,4-benzenedithiol dihydrochloride with thiophene-2,5-dicarboxylic acid, 2,2′-bithiophene-5,5′-dicarboxylic acid, and 2,2′:5′,2″-terthlophene-5,5″-dicarboxylic acid, or their corresponding diacid chlorides, respectively. Intrinsic viscosities of up to 8.1 dL/g (methanesulfonic acid, 30°C) were recorded. Polymer structures were verified by elemental analysis and spectroscopic comparison of the polymers with appropriate model compounds. Onset of breakdown under thermogravimetric analysis in air occurred in the 460-590°C range with the benzobisthiazole polymers containing a monothiophene linkage being the most stable. Films suitable for third-order optical susceptibility measurements could be prepared by extrusion techniques from the benzobisthiazole polymer containing a monothiophene linkage. Degenerate four wave mixing measurements on this film yielded a third order optical susceptibility χ(3) of approximately 4.5 × 10-10 esu. © 1993 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080310317
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  • 5
    Electronic Resource
    Electronic Resource
    Characterization, processing, and properties of an aromatic poly (ether ketone) (1991)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 29 (1991), S. 119-128 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Poly(oxy-1,3-phenylenecarbonyl-1,4-phenylene), mPEK, was synthesized in a methane sulfonic acid/phosphorus pentoxide medium through the polycondensation of 3-phenoxybenzoic acid. The polymer was soluble at room temperature in strong acids and common organic solvents. Differential scanning calorimetry on mPEK indicated a glass transition temperature of 132°C and no detectable crystal melting behavior. The polymer was thermo-oxidatively stable up to 420°C in air as determined by thermogravimetric analysis. Thermal degradation resulted in a crosslinked polymer. Compression molding was successfully applied to consolidate mPEK powder into bulk specimens without causing degradation. Tensilefractured surfaces of the consolidated specimens were examined by scanning electron microscopy which strongly indicated adequate fusion of mPEK powder but also disclosed microvoids of uniform size, shape, and distribution. X-ray scattering revealed that mPEK powder was amorphous and that the consolidated mPEK specimens were structurally isotropic as well as amorphous. The bulk specimen density was determined to be 1.29 ± 0.01 g/cm3 and the three-dimensionally isotropic bulk tensile properties were shown to be 4.10 ± 0.10 GPa (modulus), 0.07 ± 0.01 GPa (strength), and 0.021 ± 0.006 (elongation at break). Tensile properties of the amorphous mPEK specimens compared favourably with literature values of state-of-the-art semicrystalline thermoplastics. Crystaline phases could be realized for mPEK by melt-processing, or precipitating from a solvent.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1991.090290115
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  • 6
    Electronic Resource
    Electronic Resource
    Bulk rigid-rod molecular composites of articulated rod copolymers with thermoplastic pendants (1992)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 30 (1992), S. 1515-1525 
    Details
    ISSN: 0887-6266
    Keywords: articulated rigid rod ; grafted thermoplastic ; copolymer ; molecular composite ; phase separation ; consolidation ; aspect ratio ; Halpin-Tsai equation ; three-dimensionally isotropic properties ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Bulk rigid-rod molecular composites were successfully obtained by powder consolidation of a copolymer containing both the reinforcing rigid-rod segments and the thermoplastic matrix. By chemically linking the reinforcing segments and the matrix molecule, the copolymer was designed to minimize phase separation in the molecular composite. The copolymer was an articulated rigid-rod poly(p-phenylenebenzobisthiazole), aPBT, with an aromatic poly(ether ketone), mPEK, thermoplastic pendant grafted at the points of articulation. The copolymer powder was pre-formed and compression molded at an elevated temperature, which resulted in bulk rigid-rod molecular composites with three-dimensionally isotropic properties. Compared to the neat mPEK homopolymer, significant increases in glass transition temperature Tg and tensile properties have been realized for the aPBT-g(mPEK) copolymers with low rod content. Taking into account the aspect ratio of the aPBT, the bulk rigid-rod molecular composite showed a tensile modulus as predicted by the Halpin-Tsai equation. In addition, x-ray scattering revealed minimal rod aggregation. However, for the copolymer of higher rod content, significant phase separation was observed in the copolymer powder, which resulted in a decrease in Tg as well as reinforcement efficiency of the bulk rigid-rod molecular composite as compared to those derived from the copolymers of low rod content. © 1992 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1992.090301310
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