Phase behavior of polyurethane precursors.(Generation of Microcellular Polyurethane Foams via Polymerization in Carbon Dioxide, part 1): An article from: Polymer Engineering and Science

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From the author: On investigating the generation of microcellular polyurethane foam via reaction in carbon dioxide, we have observed that common polyurethane precursors are C[O.sub.2] miscible, whereas typically fluorinated compounds or specially designed surfactants are needed to solubilize polymers in C[O.sub.2]. Both isocyanates and polyols are C[O.sub.2]-miscible at workable pressures and temperatures and in useful concentrations to allow generation of polyurethane foams in C[O.sub.2]. By characterizing the phase behavior of several series of propylene oxide and ethylene oxide polyols, we have observed that the combined effects of molecular weight and hydroxyl number fix the location of the phase separation pressures. In general, lower molecular weights and lower hydroxyl mole fractions produce phase boundaries at relatively lower pressures in carbon dioxide. It also has been shown that C[O.sub.2]-soluble compounds may have a compatibilizing effect on less C[O.sub.2]-soluble materials.

Citation Details
Title: Phase behavior of polyurethane precursors.(Generation of Microcellular Polyurethane Foams via Polymerization in Carbon Dioxide, part 1)
Author: Kristen L. Parks
Publication:Polymer Engineering and Science (Refereed)
Date: October 15, 1996
Publisher: Society of Plastics Engineers, Inc.
Volume: v36 Issue: n19 Page: p2404(13)

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