Preparation of polyetherpolyols from polysaccharides, useful in polyurethane production involves addition of alkylene oxides to polysaccharides, previously reacted with phosphorus oxychloride

摘要

Polyurethane foams can be prepared from polyetherpolyols without additional catalysts and activators. polyurethane foams can be prepared from polyetherpolyols without additional catalysts and activators. Polyetherpolyols of OH number 250-500 are prepared by addition of 2-4C alkylene oxides to polysaccharides in the presence of preferably alkaline catalysts. In an introduced reaction step polysaccharide with phosphorus oxychloride is reacted with the total amount of the required C3/C4 alkylene oxide mixture, or with a propylene oxide/ethylene oxide mixture of ethylene oxide content 10-60 wt.% on the total alkylene oxide content, with subsequent alkoxylation at 60-100 deg C. The polyetherpolyol obtained is then reacted directly with diisocyanates without catalyst addition to give polyurethane foams.