The present invention relates to polyester polyols made from aromatic polyacid sources such as thermoplastic polyesters. The polyols can be made by heating a thermoplastic polyester such as virgin polyethylene terephthalate, recycled polyethylene terephthalate, or mixtures thereof, with a glycol to give a digested intermediate which is then reacted with a digestible polymer, which can be obtained from various recycle waste streams. The polyester polyols comprise a glycol-digested polyacid source and a further digestible polymer. The polyester polyols provide a sustainable alternative to petrochemical or biochemical based polyester polyols.

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.

In an embodiment, a process for forming a quenched composition comprises mixing an unquenched melt polycarbonate and a quenched melt polycarbonate to form the quenched composition; wherein the quenched polycarbonate was formed from a first melt polymerization, wherein the first melt polymerization comprises adding a quencher to form the quenched polycarbonate, wherein the unquenched polycarbonate was formed from a second melt polymerization, wherein the unquenched melt polycarbonate comprises an active catalyst used during the second melt polymerization, and wherein the second melt polymerization is free of a quencher addition.

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.

A method of continuously producing a polyol includes: (i) feeding a solid catalyst into a continuous stirred tank reactor (CSTR); (ii) contacting a reaction mixture comprising one or more epoxides and carbon dioxide with the solid catalyst and a chain transfer agent comprising a plurality of sites capable of initiating copolymerization of epoxides and carbon dioxide in the CSTR; (iii) allowing polymerization reaction to proceed until a desired molecular weight polyol has formed; and (iv) terminating the polymerization reaction.

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.

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.

In an embodiment, a melt polymerization process comprises melt polymerizing reactants in at least two polymerization units, in the presence of a catalyst composition to form polymerized polycarbonate; adding a quencher composition comprising one or both of a liquid quencher composition and a solid quencher composition; mixing the quencher composition with the polymerized polycarbonate for a period of time of greater than or equal to 5 seconds prior to the addition to the polymerized polycarbonate of any additives having a reactive OH group or reactive ester group; directing the polymerized polycarbonate to an extruder; and directing an additive to the extruder.