The Dow Chemical Company

Peter E Pierini

Ritchie A Wessling

Ming-Biann Liu

Willie E Rochefort

David R Pedersen

Peter K Kim

Reid Henry Bowman

Lalitha Reddy

Robert E Hefner, Jr

Jimmy D Earls

Donald L Schmidt

Theodore L Parker

David A Waldman

Henry N Beck

Myrna Serrano

Susan E Dollinger

Arie Cohen

Donald E McLemore

Robbert M Vermeulen

Myung H Cho

Norman L Madison, Deceased

Thomas M McCormack

David R Pederson

Mark J Semer

Described is a process for preparing a three-dimensional article of a lyotropic polymer comprising the steps of (a) forming a shaped article of a liquid crystalline solution of a lyotropic polymer; (b) washing the shaped article with a washing fluid under conditions sufficient to reduce the solvent content of the article to less than about 2,000 parts per million, wherein the dimensions of the washed article are no less than 0.05 inches by 0.05 inches by 0.05 inches. Such articles are useful for many applications, particularly those requiring fire- and/or heat-resistance.

Three-dimensional articles of lyotropic polymers and methods for the

Mesogen containing biaxially oriented films are prepared from curable mixtures containing an epoxy resin and a curing agent therefor. Certain of the mesogen containing biaxially oriented films possess unique properties, such as a metallic like, highly reflective appearance. These films are useful in adhesives, coatings, laminates or composites and the like.

Mesogen-containing biaxially oriented films

A simplified and more efficient process is described for drying (and heat-treating) a lyotropic polybenzazole film in which the film is constrained in only the machine direction during drying (and heat-treating). The amount of stretching in the transverse direction the film undergoes prior to it being coagulated can be increased to compensate for the relaxation of the film during the drying process and the lack of stretching during the heat-treating process. Films made in this manner have acceptable finished properties.

Process for the drying and heat-treatment of polybenzazole films

A structural panel for a vehicle or building contains a substrate and a layer of flame resistant polybenzazole polymer. If the substrate is heat resistant, the panel can serve as a fire barrier. If the substrate is not heat resistant, the polybenzazole layer can still serve to delay ignition and contain any volatile gases and molten polymer that forms when the panel is subjected to heat.

Fire resistant panel

Films containing polybenzazole polymer dissolved in a solvent can be mechanically stretched to provide biaxial orientation. The resulting dope film can be coagulated. The polymer film has improved properties in the direction in which stretching occurs.

Process for fabricating oriented polybenzazole films

A process for coagulating a polybenzazole film which includes contacting a lyotropic polybenzazole dope film that is constrained in at least two directions with a coagulant under conditions such that the polybenzazole polymer separates as a gelled moiety with the structure set such that further removal of solvent will result in no more than a 5% increase in the force necessary to constrain the film.

Process for coagulating and washing lyotropic polybenzazole films

Films made from polybenzazole dopes can quickly be leached to remove polyphosphoric acid and other residual solvents by passing a leaching fluid such as steam through pores in the wet, never dried film. The process can reach acceptable residual phosphorous levels (1500-2000 ppm) in as little as about 2 or 3 minutes.

Convective leaching of polybenzazole films

Articles (other than fiber) made from polybenzazole dopes can quickly be washed to remove polyphosphoric acid by a combination of initially washing with an acidic liquid and second washing with a hot leaching fluid at at least about 60.degree. C. The process can reach acceptable residual phosphorous levels (1500-2000 ppm) in as little as about 2 or 3 minutes.

Process for coagulation, washing and leaching of shaped polybenzazole

Fibers may be prepregged with a dope containing polybenzoxazole or polybenzothiazole. The prepreg may be contacted with water or another nonsolvent to coagulate the polymer and form a matrix composite.

Matrix composites in which the matrix contains polybenzoxazole or

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

The present invention pertains to a flexible organic polymeric optical fiber core having an adherent flexible organic polymeric cladding on the outer surface. More particularly, the invention relates to an organic polymeric optical fiber having a polysiloxane cladding for long term in vivo use in the tissue of a living mammal, preferably a human being. In addition to compatibility in live tissue and body fluids, such a fiber must be capable of repeatedly being deformed in a small bend radius without losing the ability to transmit light. The clad optical fibers are used to measure levels of components (e.g., pH, oxygen, carbon dioxide) in living, moving tissue such as the heart or lungs.

Plastic optical fiber for in vivo use having a biocompatible

The invention is a jacketed polymer optical fiber which comprises: an optical fiber which comprises a core formed from a light transmitting polymeric material having a first refractive index and a cladding formed from a polymeric material having a second refractive index which is lower than the first refractive index; and a jacket about the optical fiber wherein the jacket comprises a chlorinated polyethylene. The jacketed fibers of this invention have a higher service temperature than polyethylene jacketed fibers. The jacketed polymer optical waveguides of this invention are jacketed under conditions such that the optical properties of the polymer optical waveguide are not substantially degraded. The jacketed polymer optical waveguides have relatively low brittleness at use temperatures, good rigidity, and good solvent resistance. They also contain no material which tend to migrate into the polymer optical waveguide.

Growing community of inventors

Berkeley, CA, United States of America

Peter E Pierini