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  • 1
    Electronic Resource
    Electronic Resource
    Liquid crystalline epoxy resins by polyaddition of aliphatic diepoxides with 4,4′-dihydroxybiphenyl (1995)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 33 (1995), S. 1275-1281 
    Details
    ISSN: 0887-624X
    Keywords: liquid crystalline ; epoxy resins ; thermotropic ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Liquid crystalline epoxy resins were synthesized from 4,4′-dihydroxybiphenyl (DHB), which was used as a mesogenic component, and diglycidyl ethers of aliphatic glycols (ethylene glycol and 1,6-hexanediol) which were used as flexible spacers. The synthesis was carried out by the catalytic polyaddition in the melt. Triphenylphosphine was used as the catalyst. The course of the polyaddition was investigated at various molecular ratios of the reactants. It was found that both linear and branched structures were formed in the course of the synthesis. The rates of the formation of the structures were calculated. The epoxy oligomers were investigated by DSC, polarizing microscope, and x-ray and IR spectroscopy. The molecular weight distribution was determined by GPC. The dependence of liquid crystalline properties of the obtained epoxy resins on the molecular weight and on the chain length of the flexible spacer was investigated. The molecular weight of the epoxy oligomers and the length of flexible spacer influence the phase transition temperatures. © 1995 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1995.080330810
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  • 2
    Electronic Resource
    Electronic Resource
    Liquid crystalline epoxy resins by polyaddition of diglycidyl ether of 4,4′-dihydroxybiphenyl and difunctional aromatic compounds (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 21-29 
    Details
    ISSN: 0887-624X
    Keywords: liquid crystalline polymers ; epoxy resins ; thermotropic ; polymer chain extension ; catalytic polyaddition ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This work is a continuation of the authors' earlier investigations of liquid crystalline epoxy resins prepared from diglycidyl ether of 4,4′-dihydroxybiphenyl (DGE-DHBP), which was used as a mesogenic agent, and aliphatic dicarboxylic compounds, which were used as flexible spacers. In this paper, the synthesis and characterization of liquid crystalline epoxy resins, prepared from DGE-DHBP and difunctional aromatic compounds are described. Three series of liquid crystalline epoxy resins were prepared by chain extension of DGE-DHBP with isomeric hydroxybenzoic and benzenedicarboxylic acids as well as diphenols. An isophthalic-terminated polyether was applied to decrease the temperature of phase transitions. The syntheses were carried out by catalytic polyaddition in the melt. Triphenylphosphine was applied as the catalyst. The resulting epoxy resins were investigated by DSC, polarizing microscope as well as by X-ray and IR spectroscopy. The phase transition temperatures and the type of mesophase of the resulting products depend on the character of the functional groups in the chain extender and on the position of the functional groups in the aromatic ring. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 21-29, 1998
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Synthesis and properties of liquid crystalline polyurethanes (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 1211-1220 
    Details
    ISSN: 0887-624X
    Keywords: main-chain liquid crystalline polymers ; thermotropic ; polyurethanes ; synthesis ; characterization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Liquid crystalline polyurethanes were prepared from 4,4′-bis(2-hydroxyethoxy)biphenyl (BHBP) and 2,4-tolylene diisocyanate (TDI). The effect of partial replacement of BHBP by 25-75 mol % poly(oxytetramethylene) diol (PTMO, Mn = 250) on the liquid crystalline properties was studied. The BHBP/TDI/PTMO polyurethanes were obtained by one- and two-step polyaddition. The polyurethanes were investigated by DSC, polarizing microscopy, x-ray, and IR spectroscopy. The molecular weight distribution was determined by GPC. The morphology of the polymers was investigated by the SALS method. Thermogravimetric investigations of the polyurethanes were also performed. All polyurethanes containing BHBP units have liquid crystalline properties. Partial replacement of BHBP by PTMO-250 considerably changes the phase transition temperatures and the range of mesophase occurrence. More homogeneous polyurethanes were obtained, if the two-step polyaddition method was applied. The polyaddition method affects the phase transition temperatures. © 1993 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080310517
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  • 4
    Electronic Resource
    Electronic Resource
    Influence of molecular weight on some properties of liquid crystalline polyurethanes (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 3231-3237 
    Details
    ISSN: 0887-624X
    Keywords: main-chain liquid crystalline polymers ; thermotropic ; polyurethane ; molecular weight effect ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This investigation extends our previous investigations of liquid crystalline polyurethanes prepared from 4,4′-bis(2-hydroxyethoxy)biphenyl (BHBP), 2,4-tolylene diisocyanate, and poly(oxytetramethylene)diols as the flexible spacers. The influence of molecular weight of investigated polyurethanes on their properties is discussed for two series with the same content of BHBP and different lengths of flexible spacers. The polyurethanes were investigated by means of DSC, polarizing microscopy, x-ray diffractometry, and IR spectroscopy. The molecular weight distribution was determined by GPC. Morphology was studied by the SALS method. The molecular weight of polyurethanes and the length of flexible spacer influence the phase transition temperature and the range of mesophase occurrence. © 1993 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080311309
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  • 5
    Electronic Resource
    Electronic Resource
    Curing of liquid crystalline epoxy resins with a biguanide (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 2739-2745 
    Details
    ISSN: 0887-624X
    Keywords: polymer networks ; liquid crystalline epoxy resins ; curing ; ortho-tolylbiguanide ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This work extends the authors' investigations on liquid crystalline epoxy resins prepared from diglycidyl ether of 4,4′-dihydroxybiphenyl (DGE-DHBP) and aliphatic dicarboxylic compounds (ADC) or difunctional aromatic compounds. Syntheses and properties of these liquid crystalline epoxy resins are described elsewhere. In this paper a study on the curing reaction of the above mentioned liquid crystalline epoxy resins is presented. Ortho-tolylbiguanide was applied as the curing agent. The curing reactions were investigated by differential scanning calorimetry, microscopic observations and IR spectroscopy. Depending upon the temperature program of curing, it was possible to obtain polymeric networks with liquid crystalline order. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2739-2745, 1997
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Effect of the poly(oxytetramethylene)diol spacer length on some properties of liquid crystalline polyurethanes (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 3223-3230 
    Details
    ISSN: 0887-624X
    Keywords: main-chain liquid crystalline polymers ; thermotropic ; polyurethane ; spacer length effect ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Previous studies on liquid crystalline polyurethanes prepared from 4,4′-bis(2-hydroxyethoxy)biphenyl (BHBP) and 2,4-tolylene diisocyanate (TDI) were continued. In this article, a series of polyurethanes, which differ in the flexible spacer length and BHBP content is described. Poly(oxytetramethylene)diols of different molecular weights (PTMO, Mn = 250, 650, 1000, 2000) were used as flexible spacers. The polyurethanes were investigated by DSC, polarizing microscopy, x-ray diffractometry, and IR spectroscopy. The molecular weight distribution was determined by GPC. The morphology of the polyurethanes was investigated by the SALS method. Partial replacement of BHBP by 25-75 mol % PTMO and the flexible spacer length influence the liquid crystalline properties, the phase transition temperatures, and the range of mesophase occurrence. © 1993 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080311308
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  • 7
    Electronic Resource
    Electronic Resource
    Annealing effects on the thermal properties of liquid crystalline polyurethanes (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2559-2563 
    Details
    ISSN: 0887-624X
    Keywords: main-chain liquid crystalline polymers ; thermotropic polyurethane ; annealing effect ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This work is a continuation of our earlier investigations of liquid crystalline polyurethanes prepared from 4,4′-bis(2-hydroxyethoxy) biphenyl (BHBP), 2,4-tolylene diisocyanate (TDI), and poly (oxytetramethylene) diols (PTMO). The annealing effects on the thermal properties of the investigation polyurethanes are presented for three samples with the same BHBP content, different flexible spacer length, and different molecular weight of the polyurethanes. The annealed polyurethanes were investigated by means of DSC, and polarizing microscopy. The results of the thermal analysis show that the temperatures of phase transitions depend on the annealing temperature and time. These dependences are different for different molecular weights. © 1994 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1994.080321319
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  • 8
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    Coordinating Tectons: Bipyridyl-Terminated Group 8 Alkynyl Complexes (2009)
    American Chemical Society
    Details
    Publication Date: 2009-04-13
    Print ISSN: 0276-7333
    Electronic ISSN: 1520-6041
    Topics: Chemistry and Pharmacology
    Published by American Chemical Society
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