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
    Structure formation of PVDF/PMMA blends studied (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 101-105 
    Details
    ISSN: 1572-8943
    Keywords: conformation ; crystallization dynamics ; miscibility ; PVDF/PMMA blends ; simultaneous measurement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Conformational formation and crystallization dynamics of miscible PVDF/at-PMMA and PVDF/iso-PMMA polymer blends from the molten state were studied by the simultaneous DSC/FT-IR measurement. Formation of TGTG' conformation occurred before starting crystallization exothermic peak in the PMMA content (ΦPMMA) range from 0 to 0.4 for both blends. The formation rate of TGTG' conformation, crystal growth rate and surface free energy of PVDF crystal in blends depended linearly on ΦPMMA for PVDF/at-PMMA, however, those rates for PVDF/iso-PMMA slightly influenced by ΦPMMA. These results suggested that the former was miscible blend in molecular level, however, the latter was a miscible blend with large concentration fluctuation or a partially segregated system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01987426
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Kraft lignin in polyurethanes. II. Effects of the molecular weight of kraft lignin on the properties of polyurethanes from a kraft lignin-polyether triol-polymeric MDI system (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 40 (1990), S. 1819-1832 
    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: Polyurethane films were prepared by solution casting using a three-component system consisting of polymeric MDI, a propylene oxide-based polyether triol and kraft lignin fractions of different molecular weights. The polyether triol was used as soft segment. The composition of the polyurethanes was varied whereas the NCO/OH ratio was kept constant. The crosslink density increased with increasing molecular weight of the kraft lignin fraction used, which is a result of an increase in functionality of the kraft lignin with increasing molecular weight. Polyurethanes prepared from low molecular weight kraft lignin were found to be more flexible than those prepared from medium and high molecular weight kraft lignin (at lignin contents below 30%). At kraft lignin contents higher than about 30% (which at the NCO/OH ratio used corresponds to a hard segment content of about 70%), rigid and glassy polyurethanes were obtained regardless of the molecular weight of the kraft lignin fraction used.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1990.070401102
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Kraft lignin in polyurethanes. III. Effects of the molecular weight of PEG on the properties of polyurethanes from a kraft lignin-PEG-MDI system (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 41 (1990), S. 39-50 
    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: Polyurethane (PU) films were prepared by solution casting using a three-component system consisting of a low molecular weight fraction of softwood kraft lignin (KL), polyethylene glycol (PEG) of various molecular weights, and crude diphenylmethane diisocyanate (MDI) as starting materials. All films were prepared using a constant NCO/OH ratio. The effects of KL content, PEG content, and molecular weight of PEG on the tensile, thermal, and swelling properties of the PUs were studied. The results showed that the crosslink density Tg and tensile properties were essentially unaffected by variations in the sequence length of the soft segment at a given PEG content. The properties of the PUs were found to depend mainly on the soft/hard segment ratio. The behavior of the glass transition temperature upon changes in the PU composition indicated that the soft and hard segments were extensively mixed.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1990.070410105
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Effect of molecular weight on rate of enthalpy relaxation of poly (methyl methacrylate) and its oligomers (1983)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 23 (1983), S. 907-909 
    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: The enthalpy relaxation process of methyl methacrylate oligomers and poly (methyl methacrylate) was analyzed by use of the excess enthalpy (ΔHt), which was obtained from a differential scanning calorimetric measurement. The apparent relaxation time (τ½) was estimated by the assumption of the single relaxation time response. The Tg of oligomers increased with an increase of molecular weight, and approached a constant value above 1 × 104. The apparent relaxation time showed a similar molecular-weight dependency as Tg, and approached a constant value above 1 × 104. It was expected that the molecular motion which caused the enthalpy relaxation was based on the segmental motion of main chains.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760231609
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Effect of annealing at temperature around glass transition temperature on molecular orientation and shrinkage of ethylene-vinyl alcohol copolymers (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 24 (1979), S. 2277-2287 
    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 effect of annealing on the molecular arrangement of ethylene-vinyl alcohol copolymers (EVA) was studied by optical methods. Drawn samples were annealed at temperatures near the glass transition temperature Tg in two cases; the first case allowed thermal shrinkage and the second case did not. For annealing below Tg, the hydroxyl groups were rearranged only to the stable position. Thermal shrinkage occurred by annealing at temperatures between Tg and Tg + 20-30 K. In the case of annealing at temperatures above Tg + 30 K, thermal shrinkage and crystallization occurred. The crystallization by annealing made the drawn sample difficult to shrink.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070241108
    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...