Abstract:
A process for forming extended chain polyesters and block or graft polyesters or copolymers which comprises the steps of (a) forming an intimate mixture of one or more polyesters, and an effective amount of one or more effective chain extension reagent compounds and (b) heating said mixture for a time and at a temperature sufficient to form said extended chain, or graft or block copolyester or polyester; wherein the polyester used in step (a) contains no or substantially no substances which comprise elements from groups VA and VIA of the periodic table in elemental form or any other form, for example, inorganic or organic compounds, complexes or salts.
Abstract:
The present invention relates to a process for the vapor phase fluorination in the presence of a transition metal compound-chromium compound catalyst of a halogen containing no more than three carbon atoms and at least one halogen other than fluorine such that at least one of the halogens other than fluorine is replaced by fluorine. The catalyst comprises a chromium compound and at least one transition metal compound selected from the group consisting of oxides, fluorides, oxyfluorides and acid salts of Ni, Pd and Pt.
Abstract:
The invention relates to stable, environmentally acceptable azeotrope-like compositions of 1,1-dichloro-1-fluoroethane, perfluorohexane, methanol or ethanol and optionally nitromethane which are useful as degreasing agents and solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.
Abstract:
Azeotrope-like compositions comprising 1,1-dichloro-1-fluoroethane; perfluorohexane; and perfluoroheptane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.
Abstract:
Azeotrope-like compositions comprising 1,1,2,3,3-pentafluoropropane and methanol or ethanol and optionally nitromethane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.
Abstract:
A linear electromechanical actuator (10) includes back-to-back screw-type actuators (12A, 12B) whose screw nuts (16A, 16B) are secured together. During operation, the leadscrew (14A or 14B) of one screw-type actuator (12A or 12B) is rotated while the leadscrew (14A or 14B) of the other screw-type actuator (12A or 12B) is locked.
Abstract:
Thermoplastic polymeric compositions which feature good physical properties which are relatively insensitive to humidity and further exhibit good barrier properties of the compositions comprise: (A) a first conventional polyamide, and (B) an amorphous copolyamide which is polymerized from (B1) a polyamide forming monomer selected from the group consisting of lactams, aminoalkanoic acids and mixture thereof wherein the monomer is present in a molar proportion of between about 0 and 50 %, (B2) a diamine selected from the group consisting of aralkylene diamines, cycloalkylene diamines and mixtures thereof, the diamine being present in a molar proportion of between about 25 and 60 %, (B3) a dicarboxylic acid selected from the group of an aromatic dicarboxylic acid, aralkylene dicarboxylic acids, and aliphatic dicarboxylic acids; preferably the use of an aliphatic dicarboxylic acid in conjunction with an aromatic dicarboxylic acid is preferred, at least one aromatic diacid, the dicarboxylic acid being present in a molar proportion of between about 25 and 60 %, wherein the (A) and (B) are substantially miscible when formed into a blend composition. The blend composition finds use as a molding composition, as well as a film forming composition, alternatively, may be formed into a variety of articles which exhibit improved physical properties.
Abstract:
This invention relates to a branched fractal three dimensional polymer species which comprises rigid aromatic recurring units having electrophilic or nucleophilic reactive moieties on the exterior thereof. Another aspect of this invention relates to a star polymer comprising a polymeric core formed of the fractal polymers (FPS) of this invention having linear polymeric moieties grafted to an exterior thereof by way of residues formed by reaction between the reactive moieties on the exterior of the fractal polymer (FP) and complementary reactive moieties on a linear polymer. Yet another aspect of this invention relates to polymeric composites comprising a polymer matrix having dispersed therein the star polymers of this invention. Still another embodiment of this invention relates to polymeric networks comprising at least two polymeric cores formed from the fractal polymers of this invention which are bonded together by linking polymeric moieties grafted to the exterior of said at least two polymeric cores by way of residues formed by variation reaction between reactive moieties on the exterior of the fractal polymer and complementary reactive moieties on a linking polymer.
Abstract:
This invention relates to an anti-corrosive paint comprising a binder and one or more neutral or electrically conductive conjugated homopolymer or copolymers dispersed or dissolved in a liquid medium.
Abstract:
Error correction values for binary logic components used in providing a phase shift to an RF signal are optimized to provide improved overall performance. Initially, each component is adjusted to minimize the overall phase error while the other components are in an inactive state. After the initial adjustment, statistical methods based on Tables of Contrasts and Yates' Algorithm are used to determine full-factorial main effects. A full-factorial analysis is a statistical analysis in which the responses of all possible binary logic states are compared. The full-factorial analysis is used to quantify the main effects which are the error contributions of each of the individual binary logic components. These main effects are then used as error correction or adjustment values for the binary logic components.