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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 59 (2000), S. 395-408 
    ISSN: 1572-8943
    Keywords: fire retardancy ; fire testing ; polyester resins ; polymers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The use of thermal methods in the study of flammability and fire retardant action is discussed and compared with the standard test methods. This paper provides an overview with examples drawn from continuing studies on polyester resins, especially those containing halogenated monomers. Thermal analysis and cone calorimetry results are complemented byanalysis of the gaseous and solid products using a wide range of analytical methods.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 60 (2000), S. 795-805 
    ISSN: 1572-8943
    Keywords: forced gas-flow accessory ; gas-flow modulation ; high-frequency temperature modulation ; MTDSC ; PET and Saquinavir
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The purpose of this study was to investigate the feasibility of modulating the temperature programme of a conventional DSC by use of an alternating gas-flow system. Modulated temperature differential scanning calorimetry (MTDSC) is an important thermal analysis technique but suffers from a limited applicable frequency range due to the mass of the sample and DSC cell leading to the impingement of thermal conductivity effects. We suggest that the frequency limit can be increased by replacing the cell as the source of temperature modulation with an external gaseous source, directed towards the sample and reference pans. In this evaluation, an alternating gas-flow was passed through a line to a forced gas-flow accessory (FGFA). The FGFA consisted of two matched cylinders containing chambers that allowed pre-temperature-equilibration of the stream of gas before it was passed over the sample and reference pans. The development of this device revealed the essential practical requirements of gas-flow modulation for high-frequency temperature modulation. These include the following: an appropriately sealed tunable gas supply to both sample and reference pans, an effective method for high-frequency cycling of the gas-flow rate, a small aperture to deliver the flowing gas directly over the pan and a temperature equilibration chamber. The results from samples of quenched PET and amorphous Saquinavir indicate that gas-flow modulation is indeed feasible, with the FGFA able to raise the attainable temperature modulation frequency by an order of magnitude compared to conventional MTDSC.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 673-679 
    ISSN: 1572-8943
    Keywords: modulated temperature DTA ; scanning probe thermal microscopy ; thermomechanical analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Micro-thermal analysis combines the imaging facility of scanning probe microscopy with the ability to characterize, with high spatial resolution, the thermal behavior of materials. A sample may be visualized according to its surface topography and also its relative thermal conductivity. Areas of interest may then be selected and localized thermal analysis (TMA and modulated temperature DTA) performed. Applications of this new technique to study semiconductors, polymer blends and biological specimens are described.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 763-776 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Polyester thermosets have been prepared from maleic anhydride, phthalic anhydride, dibromoneopentyl glycol, and styrene, and their thermal degradation has been studied. Thermogravimetry has shown that degradation in air occurs in three main stages. For the 10% bromine polyester, the weight losses corresponded to 16.3%, 69.7%, and 13.9% of the original polymer weight - the temperatures of the DTG peak maxima being 217°C, 345°C, and 530°C, respectively. Infrared analysis of the residues showed that above 250°C there was a gradual reduction in the absorbance of all peaks with increasing temperature, indicating the degradation of all parts of the 3-dimensional polymer structure was occurring in a simultaneous manner. Degradation of the dibromoneopentyl glycol polyesters at 530°C in air proved to be a very complex process since a mixture of organic products was produced which gave rise to well over 100 peaks in the capillary column chromatograms. Under the conditions used, the low temperature degradation products proved to be rich in phthalic anhydride with no benzaldehyde being detected. The yields of benzene, toluene, styrene, and naphthalene increased with increase in temperature.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 6 (1982), S. 122-126 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A study has been made of the effect of antimony and molybdenum oxides on the temperature-critical oxygen index relationship of halogenated polyester thermosets. The polyesters were prepared from maleic anhydride, phthalic anhydride and propylene glycol, using either tetrachlorophthalic anhydride, tetrabromophthalic anhydride or chlorendic anhydride as the halogen source. Marked differences were observed in the effect of the two oxides. The critical oxygen index values of the halogenated polyesters containing maoybdenum (VI)oxide decreased with increase in timperature, which is in accordance with what is normally found for organic polymers, with and without additives. In contrast to this, the critical oxygen index values of the formulations containing antimony(II)oxide increased with increased with increase in temperature to reach a maximum value at around 100-150 °C. These results indicate that antimony(II)oxide is a better flame retardant than molybdenum(VI)oxide, since not only is it superior at the primary ignition stage but it shows enhanced activity at the higher temperatures which would be experienced by polymeric material in the early stages of a fire. It is concluded that higher temperature critical oxygen index studies provide a better guide to the flame retardant activity of additives than do ambient critical oxygen index determinations alone.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 7 (1983), S. 41-48 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A study has been made of the effect of molybdenum trioxide on the thermal degradation of a series of chlorinated and brominated polyester thermosets. Like antimony oxide, it showed flame retardant activity in all the halogenated polyesters. It was shown to affect the char yield, and the temperature and weight loss of each degradation step. X-Ray diffraction studies of the degraded dibromoneopentyl glycol polyesters showed that in air a near-quantitative yield of molybdenum trioxide was present above 550 °C. Some dioxide was present before the final char oxidation step occurred. In a nitrogen atmoshphere the trioxide was reduced to the dioxide at first, but this finally reacted to give the carbide at around 900 °C. Infrared spectroscopy showed that inclusion of the molybdenum trioxide resulted in structural changes in the high-temperature polyester residues which were more prominent when bromine was present. Elemental analysis of the residues indicated that the presence of the trioxide in the brominated polyesters accelerated the release of bromine at high temperatures and confirmed its char-promoting tendencies.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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