The present invention relates to a method for selectively separating propylene carbonate by adding water to reaction products comprising a polyether carbonate polyol and propylene carbonate, which are generated from a polymerization reaction of propylene oxide and carbon dioxide under a double metal cyanide (DMC) catalyst, wherein an economical and effective separation of propylene carbonate can be achieved.

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.

The present invention relates to a purifying apparatus for polycarbonate polyols, especially for removal of cyclic alkylene carbonates, comprising an evaporation unit (1) provided with a heater (10) and having an inlet (6) disposed at the top end thereof and a bottoms vessel (11), and a stripping column (2) connected downstream of the evaporation unit (1) and having a top (21) and a bottom (23), wherein a feed (5) for the polycarbonate polyol to be purified opens into the inlet (6) to the evaporation unit (1) and a gas outlet line (12) and a connecting line which opens into the top (21) of the stripping column (2) and is equipped with a pump (18) depart from the evaporation unit (1), and wherein a gas inlet line (24) for an inert gas opens into the bottom (23) of the stripping column (2) and a product line (27) for the purified polycarbonate polyol departs from the bottom (23) of the stripping column (2) and a gas outlet line (25) departs from the top (21) of the stripping column (2). The invention additionally relates to a process for purifying polycarbonate polyols with such a purifying apparatus.

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.

This invention relates to a process for the production of a high purity polyether carbonate polyol. The high purity polyether carbonate polyols prepared by the process herein contain a low level of catalyst residue. The process purifies polyether carbonate polyol through use of activated carbon, mixed into the polyether carbonate polyol and later removed. In addition, the activated carbon may be coated on the filter through which the polyether carbonate polyol is filtered to form the high purity polyether carbonate polyol.

Provided is an aromatic polycarbonate resin composition with high fluidity, particularly during low shear, and a good color. An aromatic polycarbonate resin composition including: an aromatic polycarbonate resin that has a structural unit expressed by general formula (1); a aliphatic cyclic carbonate that is expressed by general formula (2) and is included at a ratio of 10 ppm-10,000 ppm; an aromatic cyclic carbonate that is expressed by general formula (3); and at least one compound selected from the group consisting of compounds expressed by general formulas (4)-(6), wherein the total content of the aromatic cyclic carbonate and the compound(s) expressed by general formula(s) (4)-(6) is 0.1 mass %-2.0 mass % by bisphenol A-converted value.

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The present invention provides a method for preparing a polycarbonate by removing a solvent from a polycarbonate polymerization solution without impairing the physical properties of the polycarbonate.

The present disclosure relates to polythioaminals with applications as carriers or delivery vehicles for therapeutic agents or other small molecule cargo. Polythioaminal block copolymer coupled to a therapeutic agent is a polymer-therapeutic conjugate that exhibits higher stability and longer life time in aqueous environments. The polythioaminal block copolymer coupled to a therapeutic agent can be synthesized by reacting hexahydrotriazines with a hydrophobic block precursor, a hydrophilic block precursor, a particle stabilizing segment precursor, and a cargo, such as a therapeutic agent, in a one pot synthesis. The ease of synthesizing the resulting polythioaminal block copolymer coupled to the therapeutic agent while offering the extended stability and polymer life time in aqueous environments make the polythioaminal block copolymer particularly attractive for therapeutic carriers.

The purpose of the present invention is to provide an aromatic polycarbonate oligomer solid which has a markedly reduced amount of a low molecular weight component, has no or a markedly reduced amount of chlorine-containing compounds, has a high loose bulk density and is easy to handle. The purpose is met by an aromatic polycarbonate oligomer solid which includes a repeating unit represented by general formula (1), has a weight average molecular weight of 500 to 10000, has a low molecular weight component of less than or equal to 5.0 area % as measured by high performance liquid chromatography, and has a loose bulk density of greater than or equal to 0.20 g/cm.sup.3.

##STR00001##

A method for preparing granular polycarbonate particles is disclosed herein. In some embodiments, a method for preparing granulated polycarbonate particles includes mixing a polymerization reaction solution comprising polycarbonate and an organic solvent, and an anti-solvent solution comprising water and an anti-solvent to prepare a mixed solution, heating the mixed solution to remove the organic solvent, and drying or filtering the mixed solution to obtain granular polycarbonate particles. The granular polycarbonate particles having excellent physical properties without using a stabilizer or a surfactant can be obtain.