| abstract |
A process for the production of a polycarbonate glycol wherein a cyclic carbonate is catalyzed at elevated temperature by a cationic initiator. Compounds of structure (I) <IMAGE> (I) where R is alkylene, R' and R'' are independently hydrogen, alkyl, alkaryl, aralkyl, or aryl, are heated at an elevated temperature in the presence of cationic initiators such as trimethyl aluminum to form a polymer. Production of a glycol product is assured by subsequent heating at about 200 DEG -220 DEG C. to form a polymer containing carbonate units of <IMAGE> and having hydroxy end units bonded to a carbon not part of a carbonate function. The molecular weight of polycarbonate glycol is preferably at least about 1,000. |