Polyurethane elastomers based on polymer polyols

Abstract

Linear polyurethane elastomers based on polymer polyols were synthesized by the one-shot technique. The hard-segment content of the polyurethanes, the chain length of the base polyether, and the styrene/acrylonitrile content and/or the ratio of the polymer polyols were varied. The mechanical properties and the results of the dynamic mechanical analysis are discussed and compared with those of equivalent crosslinked polyurethane elastomers. ZUSAMMENFASSUNG:Lineare Polyurethan-Elastomere auf Basis von Polymerpolyolen wurden nach dem one-shot-Verfahren hergestellt. Der Hartsegmentgehalt der Polyurethane, die Kettenlange des Basispolyethers sowie das StyroVAcrylnitril-Verhaltnis und der Gesamtgehalt an Polymerpolyol wurden variiert. Die mechanischen Eigenschaften und die Ergebnisse der dynamisch-mechanischen Analyse werden diskutiert und mit denen von entsprechenden vernetzten Polyurethan-Elastomeren verglichen.

Phase behavior and molecular mobility in polyurethane/styrene–acrylonitrile blends

“…These multicomponent systems provide the possibility to combine the versatile properties of SPUs with other, often contrary, properties of the other components. Very often the second component is a thermoplastic hard polymer to improve the mechanical properties of the multicomponent system 2, 3. Specific physical and chemical interactions in such systems may result in a modification of the degree of microphase separation (DMS) of SPUs into microdomains rich in HS (HS microdomains) and a microphase rich in SS (SS microphase) 2, 4…”

“…The ratio of acrylonitrile and styrene in SAN is 50/50. The method of reactive blending was employed for the PUR formation with polymer polyols 2…”

Broadband Dielectric Relaxation Spectroscopy of Functionalized Biobased Castor Oil Copolymer Thermosets

“…The contribution of ionic conductivity leads to an increase in the magnitude of ε ′′ with increasing temperature, especially in the low frequency range as already mentioned. The contribution of strong ionic conductivity process at low frequency ranges must be subtracted from the original dielectric spectra to get reliable data, particularly for evaluating the effect of thermoset formation on the molecular dynamics of different relaxation processes as discussed later …”

“…The contribution of strong ionic conductivity process at low frequency ranges must be subtracted from the original dielectric spectra to get reliable data, particularly for evaluating the effect of thermoset formation on the molecular dynamics of different relaxation processes as discussed later. [ 63,64 ] The dielectric relaxation spectrum of a fully cured NCA thermoset is shown in Figure 3 . Similar to the molecular dynamics of NCO, three processes ( α -and β -relaxation processes as well as ionic conductivity) can also be seen Freeze-drying of Grubbs catalyst by dissolving 250 mg of as-received catalyst in 5 mL of benzene followed by quenching in liquid nitrogen and subsequent sublimation under vacuum at room temperature for 5 h was an important step to increase the surface area of the catalyst and its solubility in NCA and NCO monomers.…”

Miscibility Behavior of Poly Ethylene Glycol or Poly Ethylene Succinate/Chlorinated Poly Vinyl Chloride Blends Studied by Dielectric Relaxation Spectroscopy

“…This process appears at higher temperature as a rapid increase in tan(δ). This effect attributes to the existence of space charge polarization and the free charge motion within the material and also related to so called conductivity current relaxation process [18,19]. Figure 1(b) depicts the temperature dependence of tan(δ) for pure CPVC sample at some selected frequencies.…”