Abstract: The present invention is directed to a method for sustaining the catalytic activity of a carbonylation catalyst composition, after changes in reactor pressure and temperature, in the catalytic production of aromatic carbonates.

Abstract: A composition and method for promoting improved adhesion between a thermoplastic resinous substrate and polyurethane foam is provided. In one aspect of this invention, the composition comprises a thermoplastic mixture of at least one polyphenylene ether and at least one poly(alkenylaromatic) compound; and at least one primary amine-containing material or secondary amine-containing material.

Abstract: A method for removing volatile components from wet, solid polymeric materials on a vacuum vented extruder is described. Polymeric materials containing substantial amounts of water, 1-20 % by weight, are rapidly converted to polymer compositions containing less than about 0.5% by weight water at high throughput rates while avoiding complications resulting from excessive steam backflow through the extruder feed throat. The method utilizes a screw design comprising only forward flighted screw elements in an initial polymer melting and kneading zone. Steam generated as the polymer is heated and sheared flows downstream to a first vacuum vent for removal. The partially devolatilized polymer melt is then subjected to additional kneading and vacuum venting. The claimed method converts wet polycarbonate powder containing residual methylene chloride to essentially dry polycarbonate powder containing less than about 1 ppm methylene chloride.

Abstract: A method and apparatus for determining chemical properties. The method is based on the sequential measurement of the variation of the oscillation frequency of a single sensing device when different chemically sensitive film materials are deposited on both sides of a resonator such as a quartz crystal microbalance (QCM). Each of the sides of the resonator is sequentially exposed to an analyte while another side is exposed to a blank gas. In this way, the analyte-dependent signal from the resonator is generated only from a single film. Measurements are further made by switching the analyte stream to expose the sensing film on another side of the resonator previously exposed to a blank.

Abstract: A hopper feeds powder underwater to a welding torch. The hopper includes a housing having a lower chamber and an integral upper chamber. An inlet joins the upper chamber for receiving powder and a pressurized carrier gas. A powder outlet joins the lower chamber for discharging the powder to the torch. A gas outlet joins the upper chamber for releasing the carrier gas. And, a control valve joins the gas outlet for selectively controlling pressure internal the housing.