1. For binary mixtures of polybutadienes with differing molecular weights, a high temperature (or low frequency) transition was discovered, with the temperature-frequency position of the transition showing up as a function of the molecular weight of the low molecular weight constituents, and yet the transition does not depend on the concentration of these constituents. The value of the maximum for the mechanical loss tangent is determined by the concentration of low molecular weight components. 2. With regard to the viscoelastic behavior of the mixes at reduced temperatures, the transition reflects mainly the presence of the low molecular weight components, but at high temperatures the transition is indicative of the presence of the high molecular weight constituents. 3. The observed transition is associated with the manifestation of mobility of the molecules of the low molecular weight components, as a whole.
Die Diarylidencyclohexanone (I) ergeben bei der Kondensation mit Hydrazinen in siedender Essigsäure die Verbindungen (II) und mit Thioharnstoffen die Mercaptopyrimidine (III).
Bei friiheren Untersuchungen 1.2) war gefunden worden, daB die kristallinen Nitronsauren der Addukte aus Acetessigester niit P-Nitro-P-methyl-bzw. P-Nitro-P-athylstyrol, a-Nitro-cycIohexen und -cycloocten bei der thermischen Behandlung die NEFReaktion eingehen. In diesem Zusammenhang interessierte das Addukt aus a-Nitrostilben und Acetessigester.a-Nitro-stilben (I) reagiert mit Natrium-acetessigester in absol. Ather, in gleicher Weise wie andere P-substituierte P-Nitro-styrolez), zum Natriumsalz der Nitronsaure 11, dessen waBrige Losung beim Ansauern die kristalline Nitronsaure, den l-aciNitro-1.2-diphenyl-pentanon-(4)-carbonsaure-(3)-~thylester (11) liefert.Die Nitronsaure I1 ist nur rnal3ig bestandig; beim Aufbewahren bilden sich Schmieren, auch beim Erwarrnen in Losungsmitteln tritt Zersetzung ein, so daB es bisher
3‐Carbäthoxycumarin (I) reagiert mit′ alphatischen und aromatischen Aminen (II) in der Schmelze oder in siedenden Lösungsmitteln (Äthanol, Benzol, Xylol) in 60 ‐ 80% iger Ausbeute zu den Amiden (III).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.