Preparation of esters of poly-(tetramethylene ether) glycol

Claim 1

A process for preparing ester end-capped poly(tetramethylene ether) glycol, or ester end-capped poly(tetramethylene ether) glycol copolymer, the process comprising (A) bringing together, at a temperature of 0° to 120° C., (1) tetrahydrofuran, and optionally, up to 50% by weight of the tetrahydrofuran of a copolymerizable alkyl tetrahydrofuran represented by the structure ##STR7## where any one of R 1 , R 2 , R 3 or R 4 is an alkyl radical of 1 to 4 carbon atoms, the remaining R's being hydrogen; (2) an acylium ion precursor which is a compound capable of generating, under reaction conditions, an acylium ion represented by the structure ##STR8## where R is hydrogen or a hydrocarbon radical, (3) as a catalyst, a homopolymer of an ethylenically unsaturated monomer (a) containing groups such that the final polymer will contain groups of the formula ##STR9## wherein represents the polymer chain or a segment thereof; D is hydrogen, an aliphatic or aromatic hydrocarbon radical of 1 to 10 carbon atoms, a halogen or a segment of the polymer chain; X and Y are hydrogen, halogen or an aliphatic or aromatic hydrocarbon radical of 1 to 10 carbon atoms, but at least one of X or Y must be fluorine; R is a linear or branched linking group having up to 40 carbon atoms in the principal chain; and Z is hydrogen, halogen or an aliphatic or aromatic hydrocarbon radical of 1 to 10 carbon atoms; or a copolymer of monomer (a) with at least one other copolymerizable ethylenically unsaturated monomer (b), the homopolymer or copolymer being effectively free of functional groups which interfere with the reaction; and (4) optionally, an aliphatic carboxylic acid of 1 to 36 carbon atoms; and then (B) separating the resulting ester end-capped poly(tetramethylene ether) glycol product from the reaction mass.