Celanese Gmbh

Hoechst Celanese Corporation

George J Breckenridge

Ilmar L Kalnin

Harris A Goldberg

O Richard Hughes

John M Rhodes

Andrew H DiEdwardo

Howard Furst

Cubelets are made from a piezoelectrically active ceramic material having holes therein which may be cross-cored. The holes are selectively filled with a liquid curable resin, such as an epoxy. The cubelets may also be formed from bonded or sintered 'half-shapes' containing half cores, wherein a face bisects one hole or an array of holes or cross-cored holes to form one or an array of semicircular grooves or crossed semicircular grooves. The cubelets, whether filled with resin or having unfilled internal volume, are arranged in a precision array within the snug-fitting cavities of a lattice, whereby the holes are sealed off, to form a cubelet/lattice assembly which is then electroded and poled in an electric field and encapsulated in polymer to form a part of a hydrophone assembly, for example.

Devices for making piezoelectric ceramic or ceramic-base composite

A method is described for making an electroconductive composite sheet electrode which is conformable and in which a slit-and-expanded or perforated nickel screen is embedded by heat and pressure, so that electrical leads can be easily and strongly attached to the nickel screen before or after integrally bonding a electroconductive sheet electrode to each side of at least one adjacent piezoelectric ceramic/polymer composite sheet electrode which is non-conductive. After poling, the resultant transducer has an increased combined transverse stiffness which increases the hydrostatic voltage coefficient, g.sub.h, as well as the overall hydrophone Figure of Merit. Because the nickel screen is formed from a continuous metal sheet by slitting and traction or by perforation, it possesses internal electrical continuity and is much more electroconductive than a conventional woven metal wire screen of the same dimensions, thereby enabling the conductive composite electrode to show higher electrical conductivity than a similar woven wire-reinforced one and also lowering the thermally generated electrical noise of the piezoelectric composite transducer formed therefrom.

Composite conformable sheet electrodes

An improved procedure is provided for increasing the electrical conductivity of graphite via intercalation. It has been found that fully halogenated hydrocarbons (as described) have the ability to substantially aid the intercalation of graphite by previously known intercalant mixtures of (a) fluorosulfonic acid, chlorosulfonic acid, or mixtures thereof, and (b) a boron trihalide, a tetrahalide of a Group IV element, a pentahalide of a Group V element, or mixtures thereof. The presence of a fully halogenated hydrocarbon, such as carbon tetrachloride, during the graphite intercalation reaction has been found to expedite the rate at which intercalation takes place and possibly enables the achievement of a greater electrical conductivity than would have otherwise been obtained. In a preferred embodiment the graphite carbon is present within a carbonaceous fibrous material at the time of its intercalation and the resulting product is substantially electrically oriented along the axis of the fiber.

Process for the intercalation of graphitic carbon employing fully

An improved procedure is provided for increasing the electrical conductivity of graphite via intercalation. It has been found that sulfur trioxide has the ability to substantially aid the intercalation of graphite by previously known intercalants such as (a) fluorosulfonic acid, chlorosulfonic acid, or mixtures thereof, (b) a boron trihalide, a tetrahalide of a Group IV element, a pentahalide of a Group V element, or mixtures thereof, and (c) mixtures of (a) and (b). Such presence of sulfur trioxide during the graphite intercalation reaction has been found to expedite the rate at which intercalation takes place and possibly enables the achievement of a greater electrical conductivity than would have otherwise been obtained. In a preferred embodiment the graphitic carbon is present within a carbonaceous fibrous material at the time of its intercalation and the resulting product is substantially electrically oriented along the axis of the fiber.

Process for the intercalation of graphitic carbon employing sulfur

An improved process for the relatively rapid thermal stabilization of a multifilamentary acrylic fibrous material in the substantial absence of filament coalescence is provided. The fibrous material is initially contacted with a solution of hydroxylamine (as described), and subsequently with a solution of ammonium permanganate, calcium permanganate, magnesium permanganate, or mixtures thereof (as described). The resulting fibrous material which possesses a chemically altered structure is heated in an oxygen-containing atmosphere until a thermally stabilized acrylic fibrous material is formed which is capable of undergoing carbonization and is non-burning when subjected to an ordinary match flame.

Process for the production of stabilized acrylic fibers which are

Reinforced high temperature molding compositions are provided by a two step precipitation process wherein a polymer matrix comprising either (a) a nitrogenous intractable high temperature resistant polymer such as poly(bisbenzimidazobenzophenanthroline) or (b) an admixture comprising a major amount of the nitrogenous intractable high temperature resistant polymer of (a) and a minor amount of a cross-linkable polymer such as a polybenzimidazole, is affixed to the surface of a partially plasticized organic fiber derived from polymers selected from the group consisting of (1) a nitrogenous intractable high temperature resistant polymer, (2) polybenzimidazoles (3) high temperature resistant aromatic polyamides, and (4) high temperature resistant aromatic polyesters and mixtures thereof. More specifically, the matrix polymer is initially partially precipitated onto the surface of the organic fibers from a solution such as a sulfuric acid dope and then completely precipitated by an appropriate nonsolvent medium wherein the matrix polymer is affixed to the surface of the organic fiber in the form of a fiber particle aggregate. The resulting composition is capable of providing a three dimensional article having improved flexural strength.

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Clark, NJ, United States of America

George J Breckenridge