In an embodiment, a method for making a thermoplastic composition, comprising: melt polymerizing a polycarbonate, extruding and melt filtering the polycarbonate to form a melt filtered polycarbonate; forming the thermoplastic composition comprising the melt filtered polycarbonate, 0.03 to 0.05 wt % of a triacylglyceride release agent; and 0.10 to 0.14 wt % of a UV stabilizer; wherein the weight percentages are based on the total weight of the composition; and extruding the thermoplastic composition.

Provided is a method of producing a polycarbonate that enables efficient drying of a polycarbonate powder and has no risk of deteriorating the quality of a polycarbonate molded article to be obtained. The method of producing a polycarbonate includes: a step of causing an alkali aqueous solution of a dihydric phenol and phosgene to react with each other in the presence of an organic solvent to produce an organic solvent solution containing a polycarbonate; a powdering step of powdering the organic solvent solution containing the polycarbonate to provide a polycarbonate powder; and a pre-drying step of drying the polycarbonate powder to remove the remaining organic solvent, in which a drying temperature in the pre-drying step is set to a temperature lower than the glass transition temperature of the polycarbonate containing 1.5 mass % of the organic solvent by from 5 C. to 15 C.

In an embodiment, a method of dewatering a wet polymer composition comprises introducing the wet polymer composition via a polymer feed location to a powder conveying section of an extruder; wherein the wet polymer composition comprises greater than or equal to 1 wt % of water based on the total weight of the wet polymer composition; venting the water through a conveying section vent to form a dry polymer composition; melt kneading the dry polymer composition in a melt kneading section of the extruder to form a polymer melt; conveying the polymer melt in a melt conveying section of the extruder; and adding an additive in one or both of the powder conveying section and the melt conveying section.

The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Alkylene carbonates are removed from polyether-carbonate polymers by contacting the polyether-carbonate with an absorbent at a temperature of 30 to 150 C. The process is effective and inexpensive. The purified polyether-carbonate is useful for making polyurethanes as well as in many other applications.

A process for drying resinous materials, comprising: delivering, by way of a plurality of resin channels, resin fluid comprising polymer and solvent into at least first and second steam channels (101) having within a flow of steam, the first and second steam channels (101) each receiving resin fluid from a plurality of resin channels, the first and second steam channels each (101) being received by a stage 1 manifold (121), the steam and resin being delivered under conditions so as to separate at least some of the solvent from the resin fluid; and collecting at least some of the polymer from the resin fluid.

The present disclosure is directed to, in part, an aliphatic polycarbonate polymerization reaction initiated by combining an epoxide with carbon dioxide in the presence of a catalytic transition metal-ligand complex to form a reaction mixture, and further quenching that polymerization reaction by contacting the reaction mixture with an acid containing a non-nucleophilic anion produces a crude polymer solution with improved stability and processability.

In an embodiment, a polycarbonate polymerization process comprises interfacially polymerizing a carbonate compound and dihydroxy compound in the presence of an interfacial catalyst to form a polycarbonate and adding a viscosity reducing agent and a transesterification catalyst to polycarbonate upstream of a first filter to form an adjusted polycarbonate. The first filter can be replaced with a replacement filter and the adjusted polycarbonate can be introduced to the replacement filter. The flow can be diverted to a replacement filter. The process further comprises reducing the addition rate of the viscosity reducing agent and the transesterification catalyst until the addition rate is 0 mol/hr.

A method of preparing a polyalkylene carbonate resin is provided. More particularly, a method of preparing a polyalkylene carbonate resin capable of preventing polymer degradation and improving physical properties and quality of a final resin product, in which, after polymerization of polyalkylene carbonate, by-products are removed by using a large amount of water to purify a reaction mixture, and in a subsequence process of removing a catalyst residue, a primary purification method is conducted by using a filter so that a content of the catalyst in the reaction mixture is less than 1% by weight, is provided.

Provided is a method of producing a polycarbonate that enables efficient drying of a polycarbonate powder and has no risk of deteriorating the quality of a polycarbonate molded article to be obtained. The method of producing a polycarbonate includes: a step of causing an alkali aqueous solution of a dihydric phenol and phosgene to react with each other in the presence of an organic solvent to produce an organic solvent solution containing a polycarbonate; a powdering step of powdering the organic solvent solution containing the polycarbonate to provide a polycarbonate powder; and a pre-drying step of drying the polycarbonate powder to remove the remaining organic solvent, in which a drying temperature in the pre-drying step is set to a temperature lower than the glass transition temperature of the polycarbonate containing 1.5 mass % of the organic solvent by from 5 C. to 15 C.