E.i. Dupont De Nemours and Company

Invista North America S.a.r.l.

Gerfried Pruckmayr

Ivan M Robinson

George E Heinsohn

Charles Francis Palmer, Jr

Suriyanarayan Dorai

Willard L Quon

Gary Arthur Lodoen

Marianne Marsi

Robert B Osborne

Robert H Weir

Walter W Gilbert

A copolymer with recurring constituent units derived by polymerizing tetrahydrofuran, ethylene oxide and at least one additional cyclic ether that can be substituted or unsubstituted that decreases the hydrophilicity imparted to the copolymer by the ethylene oxide.

Copolymers of tetrahydrofuran, ethylene oxide and an additional cyclic ether

Treatment of poly(tetramethylene ether) glycols with acid catalysts at elevated temperatures leads to a chain coupling with rapid increase in molecular weight. Various alcohols including diols and triols can be incorporated into poly(tetramethylene ether) glycol backbone with modified properties and performance.

Block copolyethers via oxonium coupling of poly(tetramethylene ether)

A catalyst and process for preparing it and its use in polymerizing tetrahydrofuran to produce polytetramethylene ether glycol ether are disclosed. The catalyst is a blend of a fluorinated resin containing sulfonic acid groups and a fluorinated resin containing carboxylic acid groups. The catalyst is partially dried to contain from 1,000 to 2,000 ppm water, so that when it is used to polymerize tetrahydrofuran, the product polytetramethylene ether glycol will have a number average molecular weight of from 250 to 4,000.

Polymerizing tetrahydrofuran to produce polytetramethylene ether glycol

In the process of converting a poly(tetramethylene ether) diester to poly(tetramethylene ether) glycol by catalytic alcoholysis, using an alkali metal hydroxide or alkoxide as the catalyst, contamination of the polymer product can be reduced by reacting the catalyst with an acid after the alcoholysis reaction is complete, and then removing the reaction product from the reaction mass.

Process for preparing improved poly(tetramethylene ether) glycol by

In the preparation of poly(tetramethylene ether) glycol by the polymerization of tetrahydrofuran (THF) using a cationic initiator, molecular weight distribution (MWD) can be held within narrow limits by bringing the THF and the initiator together in a mol ratio such that the degree of polymerization will be at about a minimum and at a temperature which will promote about a maximum number of tertiary oxonium ions, then quickly cooling the reaction mass to -25.degree. C. to +25.degree. C., and then adding enough THF to complete the polymerization. When the desired molecular weight and MWD have been reached, the polymerization is quenched and the polymer isolated.

Method for preparing poly(tetramethylene ether) glycol having narrow

Poly(tetramethylene ether) ester is converted to poly(tetramethylene ether) glycol by alcoholysis using as a catalyst an oxide, hydroxide or alkoxide of calcium, strontium, barium or magnesium.

Alcoholysis process for preparing poly-(tetramethylene ether) glycol

The oligomeric cyclic ether content of a tetrahydrofuran/alkylene oxide polymerizate is significantly reduced by bringing the polymerizate into contact at elevated temperatures with an ion exchange resin bearing -SO.sub.3 H groups.

Method for reducing oligomeric cyclic ether content of a polymerizate

Esters of poly(tetramethylene ether) glycol are prepared by polymerizing tetrahydrofuran in a reaction mixture which contains, in addition to the tetrahydrofuran, and acylium ion precursor such as acetic anhydride, a polymeric catalyst which contains sulfonic acid groups and, optionally, a carboxylic acid such as acetic acid.

Preparation of esters of poly-(tetramethylene ether) glycol

Ester end-capped copolyether glycol is prepared by copolymerizing tetrahydrofuran and an alkylene oxide or cyclic acetal in a reaction mixture which contains, in addition to the tetrahydrofuran and alkylene oxide or cyclic acetal,

Method for preparing ester end-capped copolyether glycols

Copolyether glycols are prepared by copolymerizing alkylene oxides or cyclic acetals and tetrahydrofuran, using

Method for preparing copolyether glycols

Poly(tetramethylene ether) glycol is prepared by polymerizing tetrahydrofuran, using

Growing community of inventors

Media, PA, United States of America

Gerfried Pruckmayr