Prepn of microporous open celled foams - by removing solvent from a separated solvent/polymer phase

摘要

Preparing microporous open-celled foams by (1) dissolving >=0.3% in wt./vol. of solid polymer in a mixture of a) 10-75vol% chlorofluorocarbon solvent having B.P to -500 degrees C, M.P. -40 to +125 degrees C, melting entropy of 10 cals/degrees K/mole, plastic blow index of >=0.1g/10 min. at a reduced temp. of 0.96-0.99, and water solubility of about 2wt.% b) 90-25vol.% of one or more of (m)ethanol, isopropanol, t-butanol, dimethylformamide dimethylacetamide, dioxan, trioxan, dimethylsulphoxide, tetrahydrofuran, acetone, methyethylketone, hexamethyl phosphoramide, acetic acid, butyrolactone N-methylpyrrolidone, pyridine, morpholine, (m)ethyl cellosolve, propylcellosolve (2) adding >=10vol.% water at 0 degree C- chlorofluorocarbons B.P. to form 2 phases, (3) separating polymer-chlorofluorocarbon phase off (4) eliminating chlorofluorocarbon from this phase.