Miscibility

About: Miscibility is a research topic. Over the lifetime, 5521 publications have been published within this topic receiving 133547 citations. The topic is also known as: miscible.

Alkylammonium Formate Ionic Liquids as Organic Mobile Phase Replacements for Reversed‐Phase Liquid Chromatography

Abstract: Alkylammonium formate (AAF) ionic liquids, RNH3 + [HCO2 −], R=C2H5, C3H7, or C4H9, are prepared in high yield and purity by slowly reacting an alkylamine and formic acid in an ice bath under N2. UV spectra of undiluted ethylammonium formate (EAF), n‐propylammonium formate (PAF), n‐butylammonium formate (BAF) show no appreciable background absorbance down to about 250 nm, 270 nm, and 295 nm, respectively. Physical properties such as viscosity, melting point, decomposition temperature, density, and miscibility with common organic solvents are also determined. The viscosity of EAF of 11.5 cP at 24°C is considered very low, as compared to previously reported imidazolium or alkylammonium ionic liquids. Because of the higher viscosities, van Deemter plots using the AAF ionic liquids are shifted to lower flow rate optima, as compared to that taken with methanol. The polarity index P′ values for EAF, PAF, and BAF, chromatographically determined to be (6.4±0.1); (5.8±0.1), and (5.2±0.1) (n=5), are quite c...

129Xe NMR as a probe of polymer blends

Abstract: The miscibility of polymer binary blends was investigated using 129 Xe NMR to probe the phase morphology. Heterogeneous blends with large domain sizes exhibit two 129 Xe NMR lines. When a single resonance is obtained, the data are consistent with miscibility, yielding an upper bound on the domain size. The temperature dependence of the relative solubilities and chemical shifts of 129 Xe dissolved in the pure components may allow a determination of the phase morphology in blends exhibiting a single resonance. The method is used to show that polychloroprene and 25% epoxidized 1,4-polyisoprene are miscible

Rigid rods with flexible side chains — A route to molecular reinforcement?

Abstract: Liquid-crystalline main-chain polyesters with polystyrene side chains of different length and number per main chain were synthesized using aromatic hydroxyfunctional polystyrene (PS) macromonomers, terephthalic acid derivatives and tert-butylhydroquinone as co-diol. The molecular weight of the polystyrene side chain was varied in the range from 1000 to 20000. The influence of this novel type of substituent on the solubility, thermal behaviour and miscibility with PS as a flexible matrix polymer is discussed. The properties of the new compounds are compared to those of the respective homopolyester. The graft copolyesters are, depending on the characteristics of the polymeric substituent, soluble in common organic solvents and their thermal transition points are lowered compared to the homopolyester. Compared to blends of the homopolyester, the improvement of miscibility of the polymer-substituted rigid rods with PS as an example for a flexible matrix polymer can be valued as a step to molecular reinforcement.