The Dow Chemical Company

The Cynara Co.

Henry N Beck

Robert D Mahoney

Richard Allen Lundgard

Ritchie A Wessling

Edgar S Sanders, Jr

Hawk S Wan

Stephen E Bales

George J Quarderer, Jr

Thomas O Jeanes

Thomas Caldwell Young

David J Moll

Kent B McReynolds

Alan F Burmester

Charles Z Hotz

Bethanne L Smith

Ronald M Lacher

James E Clark

Daniel O Clark

John A Jensvold

Frederick L Coan

G Glenn Lipscomb, Ii

Mark F Sonnenschein

William E Mickols

Chieh-Chun Chau

Peter E Pierini

Robert M Nowak

Peter K Kim

Wudneh Admassu

Jiro Kawamoto

David R Pederson

Mark J Semer

Timothy M Finney

Gas separations utilizing glassy polymer membranes at sub-ambient

This invention relates to a method of and apparatus for separating component gases in a gas mixture employing a glassy polymer membrane at temperatures of 5.degree. C. or less so as to achieve superior separation of gas components.

The present invention relates to a process for preparing a microporous permselective membrane from a poly(phenylene sulfide) (PPS) polymer, an organic compound which substantially solubilizes the PPS below its melting point to form a homogenous mixture, heating the resulting mixture, extruding or casting the mixture into a membrane (fiber or film), quenching or coagulating the membrane, and leaching the membrane, while optionally drawing the membrane before, during, after leaching, or a combination thereof. In one embodiment, the solvent optionally includes an organic non-solvent to assist in obtaining the desired microporsity. The permselective polymers are useful to separate gaseous or liquid components from a mixture of components.

Process of making microporous hollow fiber or film membrane of

The invention relates to a microporous membrane prepared from unsulfonated poly(etheretherketone)-type polymers.

Microporous membranes from poly(etheretherketone)-type polymers

The invention is composition useful for preparing articles from syndiotactic polystyrene, or a mixture of syndiotactic polystyrene and isotactic polystyrene which comprises a homogeneous mixture of;

Mixtures containing stereoregular polystyrene

The invention is a crystalline fiber comprising syndiotactic polystyrene, or a mixture. Preferably the fiber is a high strength fiber isotactic polystyrene and syndiotactic polystyrene wherein the fiber is monoaxially oriented, has a tensile strength of about 10,000 psi or greater, and a modulus of about 1,000,000 psi or greater. In another aspect the invention is a process for the preparation of fibers of syndiotactic polystyrene, or a mixture of isotactic polystyrene and syndiotactic polystyrene which comprises:

High strength fibers of stereoregular polystrene

A method of preparing a microporous membrane from unsulfonated poly(etheretherketone)-type polymers.

Process for making microporous membranes from

The present invention relates to a process for the production of an article comprising a polymer itself comprising poly(etheretherketone), which process comprises:

Process for forming an article comprising poly(etheretherketone) (PEEK)

The present invention pertains to a process for the production of an article comprising a polymer itself comprising poly(phenylene sulfide), which process comprises:

Process for forming articles comprising poly(phenylene sulfide) (PPS)

This invention relates to semi-permeable isotropic syndiotactic polystyrene microporous membranes and processes for preparing such membranes.

Isotropic microporous syndiotactic polystyrene membranes and processes

This invention relates to semi-permeable anisotropic syndiotatic polystyrene microporous membranes and a process for preparing such membranes.

Anisotropic microporous syndiotactic polystyrene membranes and a process

This invention relates to novel semi-permeable isotropic or anisotropic microporous membranes fabricated from a mixture of isotactic polystyrene and syndiotactic polystyrene and a method of producing such membranes.

Microporous membranes from isotactic polystyrene and syndiotactic

A process for the preparation of a membrane comprising bisphenol-based polycabonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated wherein the halogen is Cl or Br, and the membrane prepared by such process. The process generally comprises: forming a mixture comprising (i) a bisphenol-based polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogeneated, wherein the halogen is Cl or Br, and (ii) a solvent for such polycarbonate, wherein the mixture has a sufficient viscosity to allow extrusion at temperatures at which the mixture is homogeneous; heating the mixture to a temperature at which the mixture is a homogeneous fluid and extrudable, extruding the heated mixture into a shape suitable for membrane use; passing the formed membrane through a quench zone wherein the mixture undergoes phase separation, and the major portion of the solvent is removed from the formed membrane; wherein the membrane formed is a membrane with a discriminating region capable of separating oxygen from nitrogen. Such membranes have excellent mechanical and thermal properties.

Process for preparing membranes from tetrahalobisphenol polycarbonates

The invention is a composition useful for the preparation of POWADIR membranes of a bisphenol-based polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated, wherein the halogen is Cl or Br, the composition comprising (i) a bisphenol-based polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated, wherein the halogen is Cl or Br, (ii) a solvent for such polycarbonate, and (iii) a non-solvent for such polycarbonate. The composition is useful for extruding membranes wherein the membranes formed are POWADIR membranes with a discriminating region capable of separating oxygen from nitrogen. The composition of this invention allows the formation of membranes with excellent physical properties, good separation factors for oxygen and nitrogen, with excellent fluxes.

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Walnut Creek, CA, United States of America

Henry N Beck