Search results for "Miscibility"

Structures, properties and miscibility behaviour of liquid crystalline polycatenar tetrone derivatives

1995

Abstract The tetrones represent an interesting new mesogenic building block. The results of this study show that they can be incorporated into a variety of mesophases. A smectic phase was observed in the polycatenar compound with four terminal chains as expected. The phase exhibits a tilted structure (Sc phase) to prevent void formation. The compound with six pendant chains forms a columnar phase. In spite of their structural similarity, the tetrones studied tended not to be completely miscible. However, complete miscibility with a semi-discoid phenylhydrazone was observed. When this hydrazone, which forms a columnar ‘Dho phase’, was mixed with tetrone which forms a columnar ‘Dhd phase’ a c…

1981

In order to investigate the influences of different end-groups on oligomer miscibility with other substances, oligo(propylene glycol)s bearing OH groups (OPG-OH) studied in the previous paper2, were acetylated at both ends (OPG-AC). The limits of miscibility of OPG-AC with oligo(dimethylsiloxane) (ODMS) were measured turbidimetrically. A simple and reliable method for the determination of the critical points from turbidity data is presented. The observed upper critical temperatures (Tc) increase with degree of oligomerization of ODMS (ranging from 1 to 5), whereas Tc shows a minimum when the degree of oligomerization of the OPG-AC is raised (from 1 to 57,5). For lower mol. wt. oligoglycols,…

1986

Ionic Liquids in Biphasic Ethylene Polymerisation

2011

Over the past several years there has been a considerable increase in the interest of ionic liquids as versatile reaction media for a wide variety of synthetic processes. The popularity of ionic liquids has been related primarily to their unique physical and chemical properties, which can be tailored by the judicious selection of cations and anions. These properties make it possible to use ionic liquids as solvents for many organic, inorganic, and organometallic compounds, including catalysts and co-catalysts, for various types of reactions. In particular, the polar but weakly coordinating character of ionic liquids enables them to be applied as mediums in catalysis, to immobilize various k…