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Effect of catalyst on the molecular weight advancement of poly(ethylene ether carbonate) polyols
Author(s) -
Harris Robert F.
Publication year - 1990
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1990.070400715
Subject(s) - chemistry , catalysis , sodium carbonate , ethylene carbonate , potassium carbonate , ether , polyol , adsorption , organic chemistry , nuclear chemistry , polymer chemistry , sodium , polyurethane , electrode , electrolyte
Sodium stannate is a parferred catalyst for the preparation of poly(ethylene ether carbonate) polyols. It can be removed from the polyol by treatment with acetone to precipitate most of the catalyst followed by adsorption of the soluble catalyst on Florisil and filtration. Sodium metaborate and potassium carbonate catalysts are not precipitated to any extent by acetone but can be reduced to lower levels by adsorption on Florisil and filtaration. The molecular weight of the poly(ethylene ether carbonate) polyol and the water content of the system have a strong influence on the effectiveness of this purification technique. Catalysts are more easily removed from higher molecular weight polyols with low water content. The effect of sodium stannate catalysts level on the molecular weight advancement of poly(ethylene ether carbonate) polyols has been studied. The rate of advancement to a 3000 molecular weight product is increased with good CO 2 retention (95%) when the tin level is 100–500 ppm. At higher catalyst levels, product decomposition to 1,4‐dioxane becomes increasingly important. Complete mass balances and distillate analyses are presented to show the effects of catalyst levels. The product composition is dominated by the CO 2 content of the reactant and the advancement conditions.