Phase Equilibria in Cellulose Acetate-Acetone Solutions. The Effect of the Degree of Substitution and Molecular Weight on Upper and Lower Critical Solution Temperatures

Abstract

Upper and lower critical solution temperatures have been determined for acetone solutions of cellulose acetate samples with varying degrees of substitution. The Patterson-Delmas theory of corresponding states, based on the Prigogine theory, has been used to describe the molecular weight dependence of these critical temperatures. This method is most successfully applied to the primary acetate, but the data for the secondary acetate are less amenable to this theoretical approach, possibly because of the copolymeric nature of such samples.

Miscibility of poly(styrene-co-butyl acrylate) with poly(ethyl methacrylate): Existence of both UCST and LCST

“…Annealing at higher temperatures helped remove the viscosity constraint so that any pseudo phase separation phenomenon was eliminated. Second, an upper critical solution temperature (UCST) exists for the blends,17–23 which is above 150 °C but below 250 °C so that annealing at the latter temperature makes a homogeneous blend. In order to decide between these two effects, two procedures were followed.…”

Engineered Polysaccharides: α‐1,3‐Glucan Acetates Showing Upper Critical Solution Temperature in Organic Solvents

“…[14] Polysaccharide derivatives showing upper critical solution temperature (UCST) are scarcely described in the literature. Both LCST and UCST are described for mixtures of cellulose acetate and acetone [15,16] or 2-butanone. [17] Inorganic esters like cellulose nitrate [18] or even cellulose itself were found to exhibit UCST.…”

Aortic valve in valve insertion: A note of caution and a case for possible optimism

“…LCST‐type phase separation behavior in organic media has drawn attention from academia and industry for years. Not only theoretical,23–26 but also experimental27–34 research has been reported for polystyrene, polyethylene, polypropylene, poly(1‐butene), poly(1‐pentene), poly(4‐methyl‐1‐pentene), poly(dimethyl siloxane), polyisobutylene, poly(acrylic acid), and cellulose or amylose derivatives 35, 36. These systems are understood based on free volume 23.…”