Abstract: This invention relates to an extrusion method preparing polycarbonates from a solution of an oligomeric polycarbonate. A mixture of bis(methyl salicyl)carbonate (BMSC), BPA and a transesterification catalyst are first equilibrated at moderate temperatures to provide a solution of polycarbonate oligomer in methyl salicylate. The solution is then fed to a devolatilizing extruder, where the polymerization reaction is completed and the methyl salicylate solvent is removed. The solution comprising the oligomeric polycarbonate can also be pre-heated under pressure to a temperature above the boiling point of methyl salicylate and subsequently fed to a devolatilizing extruder equipped for rapid flashing off the solvent. The method provides polycarbonate with greater efficiency than the corresponding process in which unreacted monomers are fed to the extruder. Additionally, the method of the invention does not require the isolation of a precursor polycarbonate comprising ester-substituted phenoxy terminal groups.

Abstract: This invention relates to an extrusion method preparing polycarbonates from a solution of an oligomeric polycarbonate. A mixture of bis(methyl salicyl) carbonate (BMSC), BPA and a transesterification catalyst are first equilibrated at moderate temperatures to provide a solution of polycarbonate oligomer in methyl salicylate. The solution is then fed to a devolatilizing extruder, where the polymerization reaction is completed and the methyl salicylate solvent is removed. The solution comprising the oligomeric polycarbonate can also be pre-heated under pressure to a temperature above the boiling point of methyl salicylate and subsequently fed to a devolatilizing extruder equipped for rapid flashing off the solvent. The method provides polycarbonate with greater efficiency than the corresponding process in which unreacted monomers are fed to the extruder. Additionally, the method of the invention does not require the isolation of a precursor polycarbonate comprising ester-substituted phenoxy terminal groups.

Abstract: A method and system are provided that efficiently compound high levels of inorganic filler, processing fluid and silicone polymer at a commercial rate into homogeneous filled and devolatilized silicone compositions. In the method, filled silicone compositions are compounded by compounding a filler, processing fluid and silicone polymer in a first compounding apparatus to produce a first dispersed composition and simultaneously compounding a filler, processing fluid and silicone polymer in a second compounding apparatus that shares a common extruder shaft with the first compounding apparatus to produce a second dispersed composition. The system comprises a first compounding apparatus and a sequential second compounding apparatus that shares a common shaft with the first compounding apparatus.

Abstract: A method and system are provided that efficiently compound high levels of inorganic filler, processing fluid and silicone polymer at a commercial rate into homogeneous filled and devolatilized silicone compositions. In the method, filled silicone compositions are compounded by compounding a filler, processing fluid and silicone polymer in a first compounding apparatus to produce a first dispersed composition and simultaneously compounding a filler, processing fluid and silicone polymer in a second compounding apparatus that shares a common extruder shaft with the first compounding apparatus to produce a second dispersed composition. The system comprises a first compounding apparatus and a sequential second compounding apparatus that shares a common shaft with the first compounding apparatus.

Abstract: Extrusion of a mixture of an ester-substituted diaryl carbonate, such as bis(methyl salicyl) carbonate, a dihydroxy aromatic compound such as bisphenol A and a transesterification catalyst such as tetrabutylphosphonium acetate (TBPA) affords polycarbonate having a weight average molecular weight of greater than 20,000 daltons. The extruder is equipped with one or more vacuum vents to remove by-product ester-substituted phenol. Similarly, a precursor polycarbonate having ester-substituted phenoxy endgroups, for example methyl salicyl endgroups, when subjected to extrusion affords a polycarbonate having a significantly increased molecular weight relative to the precursor polycarbonate. The reaction to form a higher molecular weight polycarbonate may be catalyzed by residual transesterification catalyst present in the precursor polycarbonate, or by a combination of any residual catalyst and an additional catalyst such as TBPA introduced in the extrusion step.

Abstract: High levels of silica, processing fluid and high molecular weight silicone polymer are compounded into a homogeneous silica filled composition without forming a preconcentrate of fumed silica and polymer. A fumed silica is fed into a unitary continuous compounding apparatus at a first location prior to addition of the silicone polymer. The fumed silica is then compounded with the silicone polymer, which is fed into the compounding apparatus at a location down-stream in the compounding apparatus from the first location. The compounding apparatus can be a co-rotating, intermeshing double screw extruder.

Abstract: A method and system are provided that efficiently compound high levels of inorganic filler, processing fluid and silicone polymer at a commercial rate into homogeneous filled and devolatilized silicone compositions. In the method, filled silicone compositions are compounded by compounding a filler, processing fluid and silicone polymer in a first compounding apparatus to produce a first dispersed composition and simultaneously compounding a filler, processing fluid and silicone polymer in a second compounding apparatus that shares a common extruder shaft with the first compounding apparatus to produce a second dispersed composition. The system comprises a first compounding apparatus and a sequential second compounding apparatus that shares a common shaft with the first compounding apparatus.

Abstract: High levels of inorganic filler, processing fluid and silicone polymer are compounded and devolatilized into homogeneous filled compositions with requisite reinforcing properties and levels of volatiles. In the method, a filler, processing fluid and silicone polymer are mixed in a first compounding apparatus to produce a dispersed composition containing volatiles. The dispersed composition is then compounded in a long extruder having an L/D ratio of greater than 50 to devolatilize the dispersed composition.

Abstract: High levels of silica, processing fluid and high molecular weight silicone polymer are compounded into a homogeneous silica filled composition without forming a preconcentrate of fumed silica and polymer. A fumed silica is fed into a unitary continuous compounding apparatus at a first location prior to addition of the silicone polymer. The fumed silica is then compounded with the silicone polymer, which is fed into the compounding apparatus at a location down-stream in the compounding apparatus from the first location. The compounding apparatus can be a co-rotating, intermeshing double screw extruder.

Abstract: Impact modified, compatibilized poly(phenylene ether)-polyamide compositions containing either a polybutene or an organosiloxane mixture give molded parts with good surface appearance, improved flow at high shear rate, and improved low temperature impact strength in comparison to control blends without added organosiloxane mixture or polybutene.

Abstract: Conductive polyphenylene ether-polyamide compositions having excellent ductility are prepared by melt blending polyphenylene ether, an unsaturated impact modifying polymer and a functionalizing compound in an initial step, optionally in combination with a portion of the polyamide, and subsequently melt blending with the remainder of the polyamide and conductive carbon black having a low volatiles content. A mixture of polyamides, illustrated by mixtures of polyamide-6 and polyamide-66, is employed.

Abstract: Compatible polyphenylene ether-polyamide blends are prepared without the need for compatibilizing compounds such as citric acid or maleic anhydride. The preparation method includes melt blending of the constituents, with other materials such as impact modifiers and fillers optionally being present, at an apparatus temperature maintained no lower than about 295° C. and a pressure maintained below about 200 torr. Blending is preferably by extrusion, with filler and optionally a portion of the polyamide being introduced downstream.

Abstract: Conductive polyphenylene ether-polyamide compositions having excellent ductility are prepared by melt blending polyphenylene ether, an unsaturated impact modifying polymer and a functionalizing compound in an initial step, optionally in combination with a portion of the polyamide, and subsequently melt blending with the remainder of the polyamide and conductive carbon black having a low volatiles content. A mixture of polyamides, illustrated by mixtures of polyamide-6 and polyamide-66, is employed.

Abstract: Compatible polyphenylene ether-polyamide blends are prepared without the need for compatibilizing compounds such as citric acid or maleic anhydride. The preparation method includes melt blending of the constituents, with other materials such as impact modifiers and fillers optionally being present, at an apparatus temperature maintained no lower than about 295.degree. C. and a pressure maintained below about 200 torr. Blending is preferably by extrusion, with filler and optionally a portion of the polyamide being introduced downstream.

Abstract: Conductive polyphenylene ether-polyamide compositions having excellent ductility are prepared by melt blending polyphenylene ether, an unsaturated impact modifying polymer and a functionalizing compound in an initial step, optionally in combination with a portion of the polyamide, and subsequently melt blending with the remainder of the polyamide and conductive carbon black having a low volatiles content. A mixture of polyamides, illustrated by mixtures of polyamide-6 and polyamide-66, is employed.

Abstract: Non-delaminating resinous compositions are prepared by blending at least one polyetherimide, at least one liquid crystalline polyester in an amount to provide lower melt viscosity, and a compatibilizing amount of at least one polyepoxy compound. The compositions may also contain a minor proportion of at least one non-liquid crystalline polyester such as poly(ethylene terephthalate) or poly(ethylene 2,6-naphthalenedicarboxylate).