E.i. Dupont De Nemours and Company

Indiana University

Ivan M Robinson

Engelbert Pechhold

Gerfried Pruckmayr

George E Heinsohn

Gelu Stoeff Stamatoff

Warren N Baxter

Walter W Gilbert

By Noelle Masukawa, Administratrix

Nicholas G Merckling, Deceased

Tetrafluoroethylene is reacted in an aqueous environment with hydroxyl radicals, generating a mixture of water soluble and water insoluble .alpha.,.omega.-perfluorodicarboxylic acids.

.alpha.,.omega.-Perfluorodicarboxylic acids

Polymeric carbonate diols are prepared by coupling segments of copolyether glycols with a dialkyl carbonate, with a cyclic carbonate, or with phosgene. The carbonate diols are useful in preparing polyurethanes.

Polymeric carbonate diols of copolyether glycols and polyurethanes

Polyether carbonate diols are prepared by coupling segments of a poly(tetramethylene ether) glycol with a dialkyl carbonate, a cyclic carbonate or with phosgene. The carbonate diols are useful in preparing polyurethanes.

Polyether carbonate diols and polyurethanes prepared therefrom

Copolyether glycols are modified so that they contain 1-25%, by weight of .beta.,.beta.'-dihydroxyalkyl sulfide moieties. These modified copolyether glycols have enhanced resistance to degradation by heat and oxygen. The invention also relates to a method of making the modified copolyether glycols, to their use as stabilizers against the degradation of the polyether chains, and to polyurethanes made with them.

Sulfur-modified copolyether glycols, a method for preparing them, and

Polypropylene ether glycol is modified so that it contains 1-25%, by weight of .beta.,.beta.'-dihydroxyalkyl sulfide moieties. These modified polypropylene ether glycols have enhanced resistance to degradation by heat and oxygen. The invention also relates to a method of making the modified PPG's, to their use as stabilizers against the degradation of the polyether chain, and to polyurethanes made with them.

Sulfur-modified polypropylene ether glycols, a method for preparing

A process is disclosed for the polymerization and interpolymerization of propylene, either alone or in admixture with ethylene, to produce polymers and copolymers of propylene. The catalyst employed is a coordination complex comprising at least some divalent titanium, or other transition metal element in lower valent state. The catalysts are prepared by mixing a higher valent titanium (or other transition metal) halide or titanate ester with a reducing agent, which can be any organometallic compound, such as a metal alkyl or aryl, including Grignard reagents, a metal hydride, or a metal including zinc and metals above zinc in the electromotive series. Hydrocarbon media can be employed advantageously for the preparation of the cataysts and for the polymerizations. The polymeric products (both homopolymers and copolymers) are linear and of high molecular weight and are useful as plastics, fibers and elastomers and for production of blends with polyethylene.

Polymer composition

Polytetramethylene ether glycol is modified so that it contains 1-25%, by weight of .beta.,.beta.'-dihydroxyalkyl sulfide moieties. These modified polytetramethylene ether glycols have enhanced resistance to degradation by heat and oxygen. The invention also relates to a method of making the modified PTMEG's, to their use as stabilizers against the degradation of the polyether chain, and to polyurethanes made with them.

Sulfur-modified polytetramethylene ether glycols, a method for preparing

Tetrahydrofuran/alkylene oxide polymerizates containing no more than 3%, by weight, of oligomeric cyclic ethers are prepared by extracting the ethers from a raw polymerizate with water.

Copolyether glycols of tetrahydrofuran and alkylene oxides having low

Block polymers containing an hydroxyalkyl phthalate ester as one of the constituent blocks and a copolymer of tetrahydrofuran and one or more alkylene oxides as one or more of the other constituent blocks are useful in preparing polyurethanes and polyesters.

Block polymers of hydroxyalkyl phthalate esters and

The resistance to degradation on exposure to high temperatures, water and organic liquids of a polyurethane prepared by reacting a tetrahydrofuran/alkylene oxide polymerizate, an organic polyisocyanate and a chain extender is significantly improved by using a tetrahydrofuran/alkylene oxide polymerizate which contains no more than about 3%, by weight, of oligomeric cyclic ethers.

Polyurethanes prepared with tetrahydrofuran-alkylene oxide polymerizates

Block polymers containing hydroquinone di-(.beta.-hydroxyethyl) ether or one of its isomers or homologs as one of the constitutent blocks and a random copolymer of tetrahydrofuran and one or more alkylene oxides as one or more of the other constituent blocks are useful in preparing polyurethanes and polyesters.

Block polymers of hydroquinone di-(.beta.-hydroxyalkyl) ethers or

Block polymers containing poly(tetramethylene oxide) as one of their constituent blocks and a random copolymer of tetrahydrofuran and one or more alkylene oxides as one or more of the other constituent blocks are useful in preparing polyurethanes and polyesters.

Block polymers of poly(tetramethylene oxide) and

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

The oligomeric cyclic ether content of a tetrahydrofuran/alkylene oxide polymerizate is significantly reduced by bringing the polymerizate into contact with an acid-activated sodium or calcium montmorillonite clay.

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.

Growing community of inventors

Wilmington, DE, United States of America

Ivan M Robinson