Battelle Memorial Institute

Eagle-Picher Industries, Inc.

Biopak Technology, Ltd.

The Goodyear & Tire Rubber Company

Rosemount Inc.

Battelle Development Corporation

Marion Laboratories

Snyder Laboratories, Inc.

Western Litho Plate and Supply Company

Richard A Markle

George E Cremeans

Richard G Sinclair

Phyllis L Brusky

Herman P Benecke

Joel D Elhard

Donald M Bigg

Wayne R Melchior

Sylvester Sowell

William R Dunnavant

Edward S Lipinsky

Alex Cheung

Edward H Parker

Melville E Hillman

John H Baker

Russell K Smith

Philip F Kurz

Edward M Harris

David L Berry

Wesley M Germon, Jr

A polymer having a crosslinked structure made from a polyol and an isocyanate where the crosslinks contain urethane and/or ester bonds made from the reaction of a benzylic hydroxyl group and an isocyanate group.

Reversible crosslinked polymers, benzylic hydroxyl crosslinkers and method

Reversible crosslinked polymers, benzylic hydroxl crosslinkers and method

Thermally reversible isocyanate-based polymers

Thermally-reversible polymer compositions are obtained by reacting compounds with isocyanate and labile-hydrogen functionality. High-performance characteristics are incorporated into the polymer by using aromatic polycarbonate, aromatic polyester, polyarylsulfide, and polyarylimidazolidine oligomers. The compositions are useful as hot-melt adhesives, coatings and especially finish surface coatings on composite materials such as polypropylene and polyethylene terephthalate, moldings and in injection reaction molding applications and composite and laminate fabrication.

Thermally-reversible isocyanate-based polymers

The present invention is directed to a method for making lactide from aqueous lactic acid. The invention method comprises converting feed aqueous lactic acid to its vapor phase. The feed vapors then are passed through a reactor maintained at elevated temperature and in which optionally is disposed an alumina catalyst. Withdrawn from the reactor is product lactide, water, and unreacted lactic acid which are subjected to separation for recovery of the lactide product. The separated unreacted lactic acid is eligible for readmission to the process for making additional lactide. This cyclic process embodiment of the present invention comprises the steps of passing make-up aqueous lactic acid feed into a vaporization zone along with unreacted aqueous lactic acid filtrate from another step of the process and therein forming aqueous lactic acid feed vapors. The thus-generated vapors that are passed through a vapor phase reaction zone held at elevated temperature for forming lactide therein. Lactide as a solid is separated from unreacted aqueous lactic acid filtrate; and the filtrate is passed into the vaporization zone in the initial step of the process.

Catalytic production of lactide directly from lactic acid

Disclosed is a method for producing cyclic esters by the conversion of hydroxy carboxylic acids and their derivatives to their respective cyclic esters. Such cyclic esters, including lactide or glycolide, are particularly useful for producing polymers which can be used to make biodegradable materials, such as biodegradable packaging material. Various methods of cyclic ester production are disclosed, including liquid phase and vapor phase reactions. Also disclosed are various methods for recovering cyclic esters from product-containing streams.

Method to produce cyclic esters

The present invention is directed to a method for making L-lactide from aqueous L-lactic acid. Aqueous lactic acid feed for present purposes comprehends an aqueous mixture of one or more of L.sub.1 A, L.sub.2 A, and L.sub.3 A, optionally with LD being present. L-lactic acid is the preferred feed configuration for making L-lactide, and is to be understood even though the configuration symbol is not used throughout this application. Aqueous lactic acid feed is treated for removal of water therefrom until a degree of polymerization (DP) not substantially above about 2 is reached. The treatment then is ceased to produce a crude LD product. LD then is separated from the crude LD product. A preferred treatment involves heating the feed at elevated temperature to remove water. LD can be separated from the crude LD product by a variety of techniques to produce an LD-depleted product. This LD-depleted product, optionally augmented with additional aqueous lactic acid and/or water then can be readmitted to the process for making additional lactide. This cyclic or recycle process embodiment of the present invention enables very high lactide conversions to be realized.

Lactide production from dehydration of aqueous lactic acid feed

Polyarylimidazolidines with a degree of polymerization of about one to twenty and having phenolic hydroxyl end groups and a novel three-step process for their preparation are described. In the first step of the process, an excess of hydrogen cyanide is reactive with an aryl diisocyanate. The excess hydrogen cyanide promotes polymerization and avoids the reaction of the imino hydrogen on the heterocyclic range with the diisocyanate to form cross linkage and associated gel formation. In the second step, a stoichiometric amount of diisocyanate is added to react with the excess hydrogen cyanide and one hydroxyl of a phenolic dihydroxyl end capping group. In the final third step, the dihydroxyl end capping group is added and the remaining diisocyanate reacts with one of the two phenolic hydroxyls on the end capping group.

Polyarylimidazolidines with phenolic hydroxyl end groups

Thermally-reversible polymer compositions are obtained by reacting compounds with isocyanate and labile-hydrogen functionality. High-performance characteristics are incorporated into the polymer by using polyimide, aromatic polycarbonate, aromatic polyester, polyphenylene sulfide, and poly(parabanic acid) oligomers. Low-temperature flexibility and toughness are imparted to the polymers by using prepolymers such as polycaprolactone diols, polytetramethylene ether glycols and polyaliphatic carbon diols. Ionic bonding and liquid-crystal functionality may also be incorporated into the compositions. The compositions are useful as hot-melt adhesives, coatings, and moldings and in injection reaction molding applications and composite and laminate fabrication.

Thermally-reversible isocyanate polymers

Processes for treating polymeric surfaces to produce smooth, durable, slippery coatings which are able to withstand the rigors of sterilization and, long term exposure to human blood and other bodily fluids without substantial loss of their slipperiness.

Process for coating polymer surfaces and coated products produced using

Epoxy and epoxy novolak resins are impact modified by adding an effective amount of a acrylamide diene nitrile rubber terpolymer to the resin. In a preferred embodiment, the acrylamide diene nitrile rubber includes an acid or ester group attached to the acrylamide portion of the polymer generally through a thiol group. The liquid terpolymer is reacted in the presence of acid catalysts with the resin to provide impact modification.

Mercapto-modified N-(R-oxymethyl) acrylamide/rubber-formable

Disclosed is a method for preparing poly(2-hydroxyethyl methacrylate) polymers (PHEMA) by a precipitation/suspension polymerization technique wherein a reaction mixture comprising hydroxyethyl methacrylate monomer (HEMA), solvent, and a free-radical initiator is subjected to heating for a time adequate for said PHEMA to be formed. The improvement in process of the present invention comprises restricting said HEMA to contain less than about 0.5 wt-% polyfunctional acrylate content, incorporating a suspending agent in said reaction mixture, agitating said reaction mixture during said heating, and restricting said solvent to one having a solubility parameter of between about 7.5 and 9, to produce PHEMA polymer particles ranging in size from about 30 to 1,000 microns and having a molecular weight ranging from about 500,000 to 2,000,000.

Preparation of PHEMA by precipitation/suspension polymerization

Epoxy and epoxy novolak resins are impact modified by adding an effective amount of an acrylamide diene nitrile rubber terpolymer to the resin. In a preferred embodiment, the acrylamide diene nitrile rubber includes an acid or ester group attached to the acrylamide portion of the polymer generally through a thiol group. The liquid terpolymer is reacted in the presence of acid catalysts with the resin to provide impact modification.

Epoxy resins modified with N-R-[(oxy or thio)methyl]acrylamide

A solventless prepolymer which is liquid at room temperature and cures at about 350.degree. F. The novel prepolymer is formed from a rubber monomer; acrylonitrile or methacrylonitrile; and an ether derivative of methylol acrylamide. The ether is formed from methylol acrylamide and an alcohol which boils above the cure temperature of the prepolymer and which preferably is hexyl carbitol. The prepolymer is formed with sufficient chain transfer agent to establish a weight average molecular weight of the prepolymer less than about 25,000. The prepolymer is heat curable to form a solid polymer with excellent compression set, tensile strength, and fuel resistivity. The method of formulating these polymers is also disclosed.

Heat curable solventless liquid prepolymer and novel monomer derived

A heat curable, solventless liquid prepolymer is prepared from a rubber monomer; a nitrile monomer such as acrylonitrile or methacrylonitrile; and a novel monomer having the following formula: ##STR1## The prepolymer is formed with sufficient chain transfer agent to establish a weight average molecular weight less than about 25,000. This low viscosity prepolymer is heat curable to form a solid rubber polymer suitable for use as a gasket.

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Columbus, OH, United States of America

Richard A Markle