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 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.

Valorization methods herein relate to undesired by-products containing compounds including the optical isometry D, in particular D-lactic acid and D-lactic acid esters. An illustrative valorization method is disclosed wherein a flux containing undesired D-lactic acid and/or undesired D-lactic acid ester(s) is subjected to a treatment in order to selectively separate a fraction rich in L-lactic acid and/or L-lactic acid ester(s) from a fraction containing D-lactic acid and/or D-lactic acid ester(s), thereby improving the efficiency of the production of L-PLA.

The present invention discloses a valorization method of a flux containing undesired D-lactic acid (ester(s)) in the production process of L-polylactic acid, the production thereof comprising: oligomerisation (30) of a substantially pure L-lactic acid feed; cyclisation (40) of the lactic acid oligomers, thereby obtaining lactides and a first residual stream transferred, at least partially, to a transesterification (80) and a hydrolysis (90) step; lactide purification (50), thereby obtaining purified lactides comprising L-lactide and meso-lactide, a second and a third residual stream, wherein the second residual stream is transferred, at least partially, to the oligomerisation (30) step and the third residual stream is transferred, at least partially, to a transesterification (80) and a hydrolysis step (90); polymerisation (60) of the purified lactides into poly lactic acid; purification (70) of the poly lactic acid, thereby obtaining purified polylactic acid comprising substantially L-polylactic acid and unreacted L-lactide, unreacted meso-lactide and impurities transferred, at least partially, to the lactide purification step (50); transesterification (80) and hydrolysis (90) of the at least partially transferred first and third residual streams, thereby obtaining a fourth and a fifth residual stream which are used, at least partially, as a base for the synthesis of molecules insensitive to the optical isometry D or L of lactic acid (esters).

The present invention discloses a valorization method of a flux containing undesired D-lactic acid (ester(s)) in the production process of L-polylactic acid, the production thereof comprising: oligomerisation (30) of a substantially pure L-lactic acid feed; cyclisation (40) of the lactic acid oligomers, thereby obtaining lactides and a first residual stream transferred, at least partially, to a transesterification (80) and a hydrolysis (90) step; lactide purification (50), thereby obtaining purified lactides comprising L-lactide and meso-lactide, a second and a third residual stream, wherein the second residual stream is transferred, at least partially, to the oligomerisation (30) step and the third residual stream is transferred, at least partially, to a transesterification (80) and a hydrolysis step (90); polymerisation (60) of the purified lactides into poly lactic acid; purification (70) of the poly lactic acid, thereby obtaining purified polylactic acid comprising substantially L-polylactic acid and unreacted L-lactide, unreacted meso-lactide and impurities transferred, at least partially, to the lactide purification step (50); transesterification (80) and hydrolysis (90) of the at least partially transferred first and third residual streams, thereby obtaining a fourth and a fifth residual stream which are used, at least partially, as a base for the synthesis of molecules insensitive to the optical isometry D or L of lactic acid (esters).

A process for recovering and purifying polyhydroxyalkanoates from a cell culture may include: (a) acidifying the culture to obtain a pH value less than or equal to 6, and submitting the culture to a cell fractionation treatment using high-pressure homogenization at a temperature greater than or equal to 10 C. and less than or equal to 80 C. to obtain a suspension; (b) basifying the suspension to obtain a pH value greater than or equal to 8; (c) diluting the suspension and submitting the diluted PHA suspension to tangential filtration to obtain a concentrated suspension as retentate and an aqueous phase as permeate; (d) submitting the concentrated suspension to bleaching; (e) diluting the suspension after the bleaching and submitting the diluted bleached suspension to tangential filtration to obtain a concentrated bleached suspension as retentate and an aqueous phase as permeate; and/or (f) submitting the concentrated bleached suspension to drying.

A process for recovering and purifying polyhydroxyalkanoates from a cell culture may include: (a) acidifying the culture to obtain a pH value less than or equal to 6, and submitting the culture to a cell fractionation treatment using high-pressure homogenization at a temperature greater than or equal to 10 C. and less than or equal to 80 C. to obtain a suspension; (b) basifying the suspension to obtain a pH value greater than or equal to 8; (c) diluting the suspension and submitting the diluted PHA suspension to tangential filtration to obtain a concentrated suspension as retentate and an aqueous phase as permeate; (d) submitting the concentrated suspension to bleaching; (e) diluting the suspension after the bleaching and submitting the diluted bleached suspension to tangential filtration to obtain a concentrated bleached suspension as retentate and an aqueous phase as permeate; and/or (f) submitting the concentrated bleached suspension to drying.

An object is to provide a PHA production method which enables efficient filtration. The above problem is solved by providing a PHA production method including a filtration step of subjecting, to dead-end filtration, an aqueous PHA suspension having a pH of 2.5 to 5.5 with use of a filter medium having an air permeability of 0.01 cc/cm.sup.2/sec to 5.0 cc/cm.sup.2/sec, the aqueous PHA suspension containing PHA surface adhesion protein in an amount of not more than 2,000 ppm, the aqueous PHA suspension having a liquid density of 0.50 g/mL to 1.08 g/mL in the filtration step.

An object is to provide a PHA production method which enables efficient filtration. The above problem is solved by providing a PHA production method including a filtration step of subjecting, to dead-end filtration, an aqueous PHA suspension having a pH of 2.5 to 5.5 with use of a filter medium having an air permeability of 0.01 cc/cm.sup.2/sec to 5.0 cc/cm.sup.2/sec, the aqueous PHA suspension containing PHA surface adhesion protein in an amount of not more than 2,000 ppm, the aqueous PHA suspension having a liquid density of 0.50 g/mL to 1.08 g/mL in the filtration step.

The present invention relates to a method for manufacturing polydioxanone particles (PDO) for a filler, more particularly to a method for manufacturing polydioxanone particles, which includes a step of mixing a solution of polydioxanone dissolved in a perfluoroalcohol with a polymer emulsion containing a polyethylene oxide-polypropylene oxide-polyethylene oxide terpolymer at a predetermined ratio to generate polydioxanone particles and then recovering the polydioxanone particles through aging and washing. The polydioxanone particles manufactured by the manufacturing method of the present invention can be favorably used as an injection for regenerating skin tissues.