Library

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
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 19 (1979), S. 756-759 
    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: Fourier transform infrared spectroscopy (FT-IR) has been applied to the study of the molecular mechanisms of transitions of atactic polystyrene above Tg. Intensity measurements of vibrational modes as a function of temperature revealed two transitions above Tg, which are designated as Tu and T′u. T′u is independent of molecular weight as opposed to the molecular weight dependent Tu whose behavior is similar to Tg. Infrared measurements are more sensitive to T′u than Tu. Conformationally sensitive bands show that T′u may be related to disruption of local order where there is a negligible barrier to conformational change.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 18 (1978), S. 128-145 
    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: Reinforcement mechanisms of fiber-glass reinforced plastics (FRP) under wet conditions are reviewed with emphasis on molecular structures of glass/matrix interfaces. Included are studies on glass surface, the glass/coupling agent interface, silane coupling agents on glass surfaces as well as in solution, the coupling agent/matrix interface, extending to the interphase of particulate-filled composites, and matrix resin. For a better understanding of wet strength of FRP, the structures under dry conditions are extensively, reviewed. The chemical bonding theory still dominates other reinforcement theories. The importance of other factors such as orientation of silane coupling agents and the restriction of matrix polymer conformations are also considered. Based on recent development in spectroscopy, molecular level research of the glass/matrix interfaces has been initiated in the past decade, yet only a few spectroscopic investigations on the function of water have appeared. It is concluded that the correlation between spectroscopic investigations and mechanical properties of a FRP is indispensable.
    Additional Material: 32 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 19 (1979), S. 162-165 
    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: The thermal and mechanical degradation of glassy polystyrene has been studied by Fourier Transform Infrared, FT-IR, spectroscopy. Using difference spectroscopy we have found that the products formed from these two modes of degradation were significantly different. This result is in contrast with other workers who found similar products for the thermal and mechanical degradation of polystyrene by mass spectroscopy. Our result suggests a reassessment of the thermal activation mechanism for mechanically-induced bond scission. We have also found that the distribution of oxidation products appears to depend upon the environment in which the polymer is mechanically degraded. Finally, we have demonstrated the utility of FT-IR spectroscopy for studying the mechanical degradation of polymers.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Brookfield, Conn. : Wiley-Blackwell
    Polymer Composites 6 (1985), S. 156-161 
    ISSN: 0272-8397
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The nuclear magnetic resonance (NMR) techniques, high-power decoupling, magic-angle spinning, and cross polarization for high resolution in solid materials have been utilized to characterize surface-modified silicas. Solid state Carbon-13 NMR was used to study the chemical adsorption of a series of organosilane coupling agents on the silica surface. The type of information that can be obtained from such surface studies includes chemical bonding between the surface and the organosilane, the effects on steric hindrance of the hydrocarbon chains of the coupling agent, and other silane-surface interactions. The approach for the analysis involved comparing the spectra of the treated silica to the spectra of the corresponding condensed coupling agents. Spectral differences in terms of changes in chemical shifts and line widths are observed. The results are interpreted in terms of chemical bonding and structural differences of the silane coupling agents adsorbed onto the surface.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Brookfield, Conn. : Wiley-Blackwell
    Polymer Composites 7 (1986), S. 231-238 
    ISSN: 0272-8397
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: FT-IR spectroscopy was used to collect spectra of γ-aminopropyltriethoxy silane (γ-APS) coupling agent deposited on KBr plates, modeling the silane interphase of composites, to study the effects of heating the γ-APS film under various environmental conditions. This coupling agent is used in fiber-reinforced epoxy composites. An aminebicarbonate salt forms when the sample is dried in a moist carbon dioxide environment giving rise to a series of bands from 2800 to 2000 centimeter-1 (cm-1) and bands at 1637 cm-1, 1330 cm-1, 696 cm-1, and 663 cm-1. The primary amine group is split into two bands at 1572 cm-1 and 1486 cm-1 in the NH3+ form. Heating removes the aminebicarbonate salt at temperatures above 95°C and condenses the γ-APS polymer to a polysilsesquioxane film. The aminebicarbonate salt partially reforms if the γ-APS film is stored in a moist CO2 environment. At temperatures above 120°C the primary amine of γ-APS is oxidized in air to imine groups. In the process of evolving the CO2 the polymer is further condensed and the amine groups can be converted to imines if the temperatures exceeds 120°C. Both processes reduce the reactivity of the coupling agent with the epoxy resin. The structure of the silane interphase must be controlled during the processing of the composite to yield materials with maximum properties.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Brookfield, Conn. : Wiley-Blackwell
    Polymer Composites 1 (1980), S. 24-31 
    ISSN: 0272-8397
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Computerized infrared analysis is applied to the characterization of a glass-reinforced crosslinked polyester. The method of factor analysis determines the number of independent components which constitute the polymeric matrix. Subsequently, the spectra of those components are fitted by a least-squares criterion to spectra of the multicomponent matrix, or, if the glass spectrum is included as an additional component, to the spectra of composites. The least-squares coefficients yield the matrix composition in terms of the initial reactant composition and the extent of crosslinking.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Brookfield, Conn. : Wiley-Blackwell
    Polymer Composites 2 (1981), S. 81-88 
    ISSN: 0272-8397
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Computerized infrared analysis is applied to the characterization of a glass-reinforced crosslinked polyester. The method of factor analysis determines the number of independent components which constitute the polymeric matrix. Subsequently, the spectra of those components are fitted by a least-squares criterion to spectra of the multicomponent matrix, or, if the glass spectrum is included as an additional component, to the spectra of composites. The least-squares coefficients yield the matrix composition in terms of the initial reactant composition and the extent of crosslinking.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Brookfield, Conn. : Wiley-Blackwell
    Polymer Composites 9 (1988), S. 151-157 
    ISSN: 0272-8397
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Differential scanning calorimetry, Fourier transform infrared, and solid-state carbon 13 nuclear magnetic resonance were used to study the silane coupling agent/epoxy resin interface. Penetration of epoxy into the hydrolyzed silane has been shown. The addition of a solvent can further increase the penetration of epoxy into the hydrolyzed silane by decreasing the viscosity of the epoxy. Bulk models of the gradient in the silane coupling agent/epoxy interface have shown that the concentration of silane and the degree of hydrolysis of the silane can determine the rigidity or mobility of the interphase region. When the silane is hydrolyzed, the possible formation of entanglements may increase the rigidity of the system and decrease the degree of phase separation through the formation of an interpenetrating network.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...