Patent classifications
C08G63/89
Process for isolating PHA from a PHA-containing bacterial biomass
The method isolates polyhydroxyalkanoate (PHA) from a PHA-rich bacterial biomass, to the PHA isolated by the method and to a PHA having specific properties. The method treats an aqueous suspension of the PHA-rich bacterial biomass with a minimal amount of sodium hypochlorite, a methanol wash and extraction of PHA from the biomass with dimethyl carbonate (DMC).
Process for isolating PHA from a PHA-containing bacterial biomass
The method isolates polyhydroxyalkanoate (PHA) from a PHA-rich bacterial biomass, to the PHA isolated by the method and to a PHA having specific properties. The method treats an aqueous suspension of the PHA-rich bacterial biomass with a minimal amount of sodium hypochlorite, a methanol wash and extraction of PHA from the biomass with dimethyl carbonate (DMC).
MEDIUM OR HIGH MOLECULAR WEIGHT POLYESTER POWDERS, POWDER COATING COMPOSITIONS, AND PROCESSES OF MAKING POWDERS
A process of providing a medium or high molecular weight polyester powder, the resultant polyester polymer powder, and a powder coating composition that includes such powder; wherein the process includes: providing or forming an ester oligomer; converting the oligomer to a polyester polymer by stirring at elevated pressure and elevated temperature a reaction mixture that includes the oligomer and a nonreactive carrier capable of forming an azeotrope with water and xylenes; removing water from the reaction mixture via azeotropic reflux to provide a syrup including a medium or high molecular weight polyester polymer in the nonreactive carrier; and applying a vacuum to remove the xylenes from the syrup and form a solid (which may be in the form of a powder or subsequently formed into a powder) that includes the medium or high molecular weight polyester polymer.
MEDIUM OR HIGH MOLECULAR WEIGHT POLYESTER POWDERS, POWDER COATING COMPOSITIONS, AND PROCESSES OF MAKING POWDERS
A process of providing a medium or high molecular weight polyester powder, the resultant polyester polymer powder, and a powder coating composition that includes such powder; wherein the process includes: providing or forming an ester oligomer; converting the oligomer to a polyester polymer by stirring at elevated pressure and elevated temperature a reaction mixture that includes the oligomer and a nonreactive carrier capable of forming an azeotrope with water and xylenes; removing water from the reaction mixture via azeotropic reflux to provide a syrup including a medium or high molecular weight polyester polymer in the nonreactive carrier; and applying a vacuum to remove the xylenes from the syrup and form a solid (which may be in the form of a powder or subsequently formed into a powder) that includes the medium or high molecular weight polyester polymer.
Advanced processing of absorbable poly(p-dioxanone) containing high level of p-dioxanone monomer
The present invention is directed methods of making absorbable poly(p-dioxanone) pellets by melt polymerization of p-dioxanone conducted in a single reactor with a temperature regulator by charging a melt reactor with a mixture of p-dioxanone (PDO) monomer, initiator, catalyst, and optionally a dye; melt polymerizing the mixture in the melt reactor with sufficient agitation of the mixture to allow complete mixing of the monomer and for sufficient time to form a PDO polymer product having an unreacted PDO monomer content of at least 65 mole percent; placing the PDO polymer product under a vacuum to remove at least portion of unreacted PDO; discharging the PDO polymer product from the melt reactor directly into an in-line, underwater pelletizer to produce undried PDO pellets, collecting the undried PDO pellets, and storing the collected PDO pellets in the freezer or a vacuum chamber prior to drying.
Advanced processing of absorbable poly(p-dioxanone) containing high level of p-dioxanone monomer
The present invention is directed methods of making absorbable poly(p-dioxanone) pellets by melt polymerization of p-dioxanone conducted in a single reactor with a temperature regulator by charging a melt reactor with a mixture of p-dioxanone (PDO) monomer, initiator, catalyst, and optionally a dye; melt polymerizing the mixture in the melt reactor with sufficient agitation of the mixture to allow complete mixing of the monomer and for sufficient time to form a PDO polymer product having an unreacted PDO monomer content of at least 65 mole percent; placing the PDO polymer product under a vacuum to remove at least portion of unreacted PDO; discharging the PDO polymer product from the melt reactor directly into an in-line, underwater pelletizer to produce undried PDO pellets, collecting the undried PDO pellets, and storing the collected PDO pellets in the freezer or a vacuum chamber prior to drying.
POLYHYDROXYALKANOATE PRODUCTION AND RELATED PROCESSES
Embodiments of the invention relate generally to processes for the production and processing of polyhydroxyalkanoates (PHA) from carbon sources. In several embodiments, PHAs are produced at high efficiencies from carbon-containing gases through the utilization of a regenerative polymerization system.
POLYHYDROXYALKANOATE PRODUCTION AND RELATED PROCESSES
Embodiments of the invention relate generally to processes for the production and processing of polyhydroxyalkanoates (PHA) from carbon sources. In several embodiments, PHAs are produced at high efficiencies from carbon-containing gases through the utilization of a regenerative polymerization system.
STENTS
The invention provides bioresorbable polymeric stents made from polymer blends which include polyhydroxyalkanoates (PHAs). In particular, the invention provides stents having a stent body which comprises a polymer blend comprising: (a) from 5 to 40 wt. % of a first component which is a PHA copolymer comprising two or more different medium chain length hydroxyalkanoate monomer units; and (b) from 60 to 95 wt. % of a second component which is either a PHA homopolymer containing a short chain length hydroxyalkanoate monomer unit, or a polylactide (PLA). The invention further relates to polymer blends comprising (a) and (b).
STENTS
The invention provides bioresorbable polymeric stents made from polymer blends which include polyhydroxyalkanoates (PHAs). In particular, the invention provides stents having a stent body which comprises a polymer blend comprising: (a) from 5 to 40 wt. % of a first component which is a PHA copolymer comprising two or more different medium chain length hydroxyalkanoate monomer units; and (b) from 60 to 95 wt. % of a second component which is either a PHA homopolymer containing a short chain length hydroxyalkanoate monomer unit, or a polylactide (PLA). The invention further relates to polymer blends comprising (a) and (b).