Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Structural and mechanical properties of polybutadiene-containing polyurethanes (1981)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 21 (1981), S. 163-171 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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: A series of segmented polyurethanes based on hydroxylterminated polybutadienes (HTPBD) and their hydrogenated derivatives (HYPBD) has been synthesized. Thermal, mechanical, and spectroscopic studies were carried out over a wide temperature range to elucidate the structure-property relationships existing in these polymers. Both thermal and dynamic mechanical response showed a soft segment Tg at -74°C for the unsaturated polyurethanes and at -69°C for the hydrogenated samples. In addition, two hard segment transitions are observed by differential scanning calorimetry (DSC) at 40 and 75°C and a softening region by thermal mechanical analysis (TMA) at 190°C. The low Tg, very close to that of the free HTPBD and HYPBD and independent of hard segment content, indicated that these polymers were well phase separated. Results of infrared analysis revealed that at room temperature, 90-95 percent of the urethane N-H groups formed hydrogen bonds. Since hydrogen bonding resides only within the hard segment domain in these butadiene-containing polyurethanes the extent of H-bonding served as additional evidence for nearly complete phase segregation. From dynamic mechanical studies, the plateau modulus above the soft segment Tg and stress-strain behavior depended upon the concentration of hard segments. A slight increase in the modulus, a moderate increase in stress (σb), and decrease in elongation accompanied a higher hard segment content. The thermal and mechanical response of these polyurethanes appears to be consistent with behavior observed for other phase segregated systems. Variations in behavior resulting from hydrogenation of the precursor prepolymer are discussed.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760210309
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Deformation studies of polystyrene/poly(vinyl methyl ether) blends by mechanical-vibrational spectroscopy (1983)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 23 (1983), S. 861-868 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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: We have analyzed the deformation behavior of compatible and incompatible polystyrene (PS) and poly(vinyl methyl ether) (PVME) blends by a combination of mechanical and vibrational spectroscopy. Macroscopic properties and segmental orientation were found to be sensitive to molecular weight, strain rate, and temperature of measurement above the glass-transition temperature. Considerably different orientation functions were found for the PS and PVME components. For the experiments carried out above the Tg of the blends, the deformation behavior measured was consistent with expectations of a rubbery network.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760231602
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Thermal and mechanical properties of linear segmented polyurethanes with butadiene soft segments (1981)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 21 (1981), S. 668-674 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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: A series of segmented polyurethanes based on a hydroxyl terminated polybutadiene soft segment (HTPBD) have been prepared with varying hard segment content between 20 and 60 weight percent. These materials are linear and amorphous and have no potential for hydrogen bonding between the “hard” and “soft” segments. The existence of two-phase morphology was deduced from dynamic mechanical behavior and thermal analysis. Both techniques showed a soft segment glass transition temperature, Tgs, at -56°C and hard segment transitions between 20 and 100°C, depending on the urethane content. The low value of Tg, only 8° higher than the Tg of free HTPBD and independent of hard segment concentration indicated nearly complete phase segregation. Depending on the nature of the continuous and dispersed phases, the urethanes behaved as elastomers below 40 weight percent hard segment or as glasslike materials at higher hard segment contents. The effect of thermal history on transitions of the HTPBDurethanes was also investigated and the results suggest that the absence of hydrogen bonding to the soft segment must account for the extraordinary insensitivity to thermal history in dynamic mechanical, thermal and stress-strain behavior. Comparisons are made to the more common polyurethanes containing polyether and polyester soft segments.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760211108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Vibrational spectroscopic characterization of rigid rod polymers: IV. Crystalline modifications of poly(p-phenylene terephthalamide) (1983)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 23 (1983), S. 543-547 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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: Infrared spectroscopy (4000-50 cm-1) was used to characterize the two crystalline modifications of poly(p-phenylene terephthalamide). Polarized studies revealed that hydrogen bonds are oriented primarily perpendicular to the film plane in both forms. We also found that the crystalline modification coagulated in water could be transformed into the other form by annealing at high temperatures.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760231003
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Vibrational spectroscopic study of poly(ethylene terephthalate) crystallized by annealing in the oriented state (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 223-230 
    Details
    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: Poly(ethylene terephthalate) filament yarn has been annealed in nitrogen atmosphere, in silicone oil, or in nonreacting organic solvents. Morphological changes resulting from the annealing processes have been followed by Raman spectroscopy. Crystallinity, as evidenced by the width of the 1730 cm-1 carbonyl stretching vibration, is shown to affect the macroscopic properties of these filaments. Furthermore, these spectroscopic results, together with shrinkage measured, suggest that the shrinkage and the crystallization processes in the polymer fiber proceed at different rates in different fluid media.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1981.070260121
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Polyurethane ionomers. I. Structure-properties relationships of polyurethane ionomers (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 2467-2479 
    Details
    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: The influence of chemical structure on mechanical properties of polyurethane ionomers (PU ionomers) has been examined. NCO-terminated prepolymers prepared from primarily 4,4-methylene bis(phenyl isocyanate) (MDI) and poly(oxytetramethylene) glycol (PTMO) were chain extended with tertiary amine-containing diols and the ionomers obtained by quaternization of the prepolymers. The N-methyldiethanolamine chain extender gave the best physical properties. The mechanical properties of the PU ionomers were improved with decreasing chain length of PTMO and with increasing concentration of quaternary ammonium centers (or NCO/OH ratio of PU prepolymers). A lower degree of quaternization resulted in a decrease in the mechanical properties of the resulting PU ionomers, but their properties could be improved by post-quaternization. The adhesion of the PU ionomers to aluminum and the glass transition temperature increased with increasing concentration of quaternizing centers.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1984.070290804
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Fourier-transform infrared study of the nematic order in thermotropic main-chain polyesters (1986)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 24 (1986), S. 827-837 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Infrared spectroscopy has been used to analyze the microstructures of liquid-crystalline polymers in various mesophases. It was quite evident that there is little indication of conformational order associated with the flexible polymethylene sequences in the nematic or isotropic phases. However, additional spectroscopic evidence does suggest that polyesters with an even number of methylene units have a higher degree of lateral order when compared to those with an odd number in the liquid-crystalline state.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1986.090240409
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Spectroscopic study of a model composite: Compressive behavior of the reinforcement fiber and the buildup of thermal residual stress (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 27 (1989), S. 337-353 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The compressive behavior of polydiacetylene (PDA) single-crystal fiber and the buildup of thermal residual stress in PDA/epoxy model composite systems have been studied by Raman-mechanical spectroscopy. The compressive failure of the PDA fiber has been directly observed when the macroscopic compressive stress, applied during a bending experiment, exceeds a critical value. Fiber failure in model composites caused by thermal residual stress can also be observed by Raman measurements as well as optical microscopy. In fact, the most clear indication of fiber failure was the observation of kink bands formed. The thermal residual stress buildup which resulted from significant temperature changes in this model composite have also been studied. Contrary to most accepted views, our analysis showed the adhesion between the reinforcement fiber to the epoxy matrix to be strong.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1989.090270209
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Structural changes and chain orientational behavior during tensile deformation of segmented polyurethanes (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 2085-2098 
    Details
    ISSN: 0887-6266
    Keywords: orientation ; polyurethane ; deformation ; orientation function ; hydrogen bond ; hard domain ; soft domain ; infrared dichroism ; relaxation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Structural changes and segmental orientation behavior of polyurethane have been studied during uniaxial deformation. The orientation function change of the two (free and hydrogen bonded C=O stretching peaks) peaks during a full cycle of deformation has been observed to be distinctively different. Even though the hydrogen-bonded C—O peaks showed hysteresis behavior, the free C—O peaks exhibited quite elastic behavior. It was thus concluded that the orientation behavior of free and hydrogen-bonded C—O stretching peak represents the deformation characteristics of soft and hard domains, respectively. The orientation behavior at different temperatures also has been studied. Temperature has a significant effect on the orientation behavior of the soft domain, whereas it has negligible effect on the hard domain orientation. It was also demonstrated that the structural change due to the deformation could be analyzed by infrared spectroscopy. Some of the hydrogen-bonded carbonyl groups have been observed to be transferred to the free carbonyl groups, indicating that a small amount of the hard segments in the hard domain have been pulled out into the soft matrix upon deformation. The orientational relaxation also has been studied as a function of time. The segmental relaxation of the hard segments appears to be quite characteristic depending on the nature of the domain in which they reside. © 1994 John Wiley & Sons, Inc.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1994.090321215
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Vibrational analysis of peptides, polypeptides, and proteins. XXI. β-Calcium-poly(L-glutamate) (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1565-1594 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The observed Raman and ir spectra of Ca-poly(L-glutamate) in the β conformation have been analyzed by means of a normal mode calculation. The force field for the main chain was transferred without refinement from β-poly(L-alanine), yet it provides a good prediction of the observed bands and, in particular, explains subtle differences in the spectra of these two β-sheet structures. Main- and side-chain modes are well characterized, and the dependence of the amide III frequency on side-chain composition is again demonstrated.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230811
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...