Polymer Processing with Supercritical Fluids

The symbols used in this chapter are listed at the end of the under Notation . 

Supercritical Carbon Dioxide in Polymer Reaction Engineering 

Copyright 2005 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim 

Phase Behavior of COa/Polymer Systems and the Effect of CO2 on Polymerson Polymers 

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Report 176 Polymer Processing with Supercritical Fluids,... 

Polymer processing with supercritical fluids can result in the formation of very fine powders, fine fibers, microspheres, microballoons, and thin films. As indicated in Table 24.6 very fine particles with submicron diameters and ultra-thin films (6 nm) were obtained using RESS. Tepper and... 

S.G. Kazarian, Polymer processing with supercritical fluids. Polymer Science Series C 42(1) (2000) 78-101. 

Eckert, C.A., Kazarian, S.G., West, B.L. and Brantley, N.N. (1998) Polymer Processing with Supercritical Fluids Partitioning of Solutes and cosolvents between Supercriti Fluids and Polymer Matrices, Proceedings of the 5 Meeting on Supercritical Fluids, Nice, pp. 85-88. 

Polymers and Supercritical Fluids. Prior to the mid-1980s, Httie information was pubhshed regarding polymer processing with supercritical and near-critical fluids (1). In 1985, the solubiUties of many polymers in near- and supercritical CO2 were reported. These polymers were examined for thek abiUty to increase viscosity in C02-enhanced oil recovery (24). Since then, a number of studies have examined solubiUties of polymers in... 

Kazarian SG, Martirosyan GG. Spectroscopy of polymer/drug formulations processed with supercritical fluids in situ ATR-IR and Raman study of impregnation of ibuprofen into PVP. Int J Pharm 2002 232 81-90. 

In addition, PEEK-WC membranes have been prepared by using a phase inversion process with supercritical fluids. The supercritical fluid acts as a non-solvent. In comparison to the dry/wet phase inversion method, the supercritical fluid allows the cell size and the membrane morphology to modulate by changing the experimental conditions, such as polymer concentration, temperature, and pressure. A dry membrane can be obtained rapidly and without additional post-treatments. ... 

The interaction of CO2 and polymers can be divided into three application areas processing of swollen or dissolved polymers and applications where carbon dioxide does not interact with the polymer. An extensive review on polymer processing using supercritical fluids has been written by Kazarian [55], including possible applications based on the specific interaction of CO2 and the polymer system involved. 

Woo JS, Kim HJ, Kim Y (2006) Method for the preparatin of paclitaxel sohd dispersion by using the supercritical fluid process and paclitaxel solid dispersion prepared thereby, Google Patents Yeo S-D, Kiran E (2005) Formation of polymer particles with supercritical fluids a review. J Supercrit Fluids 34(3) 287-308... 

An extensive review on polymer processing using supercritical fluids by Kazarian [21] includes the applications mentioned above. To illustrate the possibilities of polymer processing with SCCO2 from an engineering point of view, two important applications will be discussed in more detail, namely extraction (see Section 21.2.3.1) and impregnation (Section 21.2.3.2). 

For the design of new, innovative processes to separate low-volatile components such as drugs or polymers with supercritical fluids, experimental data are needed. We designed and built a new apparatus capable of investigating phase equilibria in the occuring complex systems up to 200 bar and 250°C. Phase transitions are determined optically. Samples of the coexisting phases even at high concentration and viscosity are taken. Solid particles can be collected. 

Krukonis, V, Processing of Polymers with Supercritical Fluids, Polymer News, 11 7-16 (1985)... 

Yasuda, K. Yamaki, H. Injection molding technology with CO2 as a plasticize of resin. Proc. of international workshop of foam processing and supercritical fluid aided polymer processing. Tokyo, 2003 113-116. 

Reference to parts of this patent was made in Chapter 9. There are actually two processes described that are carried out with supercritical fluids fractionation of solid polymers and comminudon of solid polymers that are normally difficult to obtain in the form of fine granules or powders. In the examples given, a number of polymers, operating condidons, and observadons are presented. C)ne of the examples is presented here for its informadonal value. 

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