GB983916A - Improvements in or relating to the manufacture of polymeric materials - Google Patents

Abstract

Alkylene oxide polymers are prepared by reacting an alkylene oxide with an active hydrogen containing compound and an alkaline derivative thereof characterized in that there is present at the start of the reaction, in addition to said active hydrogen containing compound and alkaline derivative thereof, an alkylene oxide polymer which is itself a reaction product of an alkylene oxide and an active hydrogen containing compound and/or an alkaline derivative of said alkylene oxide polymer. Specified alkylene oxides used are 1,2-alkylene oxides, e.g. propylene oxide, butylene oxide and styrene oxide. The active hydrogen containing compounds have at least one active hydrogen atom as determined by the Zerewitinoff method and include glycerol, pentaerythritol, erythritol mannitol, sorbitol, glycose, sucrose, oxalic acid, succinic, citric and maleic acids. Preferably the number of active hydrogen atoms in the active hydrogen containing compound approximates to the combined number of methyl, methylene and methine groups therein. The alkylene oxide polymer, present at the start of the reaction, preferably in amounts of 2% to 15% of the total weight of the reagents, has a molecular weight of at least 500 and may be based on the alkylene oxide used as starting material. The polymer produced has a molecular weight of at least ten times the molecular weight of the active hydrogen containing compound. Examples 2 and 4 describe the reaction of propylene and glycerol in presence of a propylene oxide/glycerol polymer of molecular weight 4200 and potassium hydroxide to give polymers of molecular weight 4270 and 6200. Antioxidants such as hindered phenols and aromatic amines may be added to the polymers which may be reacted with polyisocyanates to give polyurethanes.