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.

It is an object to provide P3HA in which impurities (in particular, residual protein) are reduced, at a high yield, from microbial cells containing P3HA. The above object is attained by a method for producing P3HA having a weight average molecular weight of 100,000 to 700,000, the method including: (a) a step of adjusting the pH of a culture solution including microbial cells containing P3HA to 8.0 to 12.0; (b) a step of adding an enzyme to the culture solution to perform an enzyme treatment; and (c) a step of adjusting the pH of the culture solution to 10.0 to 12.0.

It is an object to provide P3HA in which impurities (in particular, residual protein) are reduced, at a high yield, from microbial cells containing P3HA. The above object is attained by a method for producing P3HA having a weight average molecular weight of 100,000 to 700,000, the method including: (a) a step of adjusting the pH of a culture solution including microbial cells containing P3HA to 8.0 to 12.0; (b) a step of adding an enzyme to the culture solution to perform an enzyme treatment; and (c) a step of adjusting the pH of the culture solution to 10.0 to 12.0.

The present invention relates to a method for producing biodegradable microspheres having improved safety and storage stability, and a method for producing the same. The present invention provides a method for preparing said biodegradable microspheres while minimizing the morphological changes of microspheres and significantly reducing residual solvents.

Producing a resin from an organic waste product includes assessing a weight percent of a first volatile fatty acid and a weight percent of a second volatile fatty acid in a liquid mixture having volatile fatty acids from the organic waste product. The weight percent of the volatile fatty acids is based on the total weight of the carboxylic acids in the liquid mixture, the total weight of volatile fatty acids in the liquid mixture, or the total weight of lactic acid and volatile fatty acids in the mixture. A ratio of the weight percent of the first volatile fatty acid to the weight percent of the second volatile fatty acid in the liquid mixture is adjusted to yield a modified liquid mixture. The modified liquid is combined with polyhydroxyalkanoate-producing bacteria to yield a polyhydroxyalkanoate copolymer; and the polyhydroxyalkanoate copolymer is extracted from the polyhydroxyalkanoate-producing bacteria.

Producing a resin from an organic waste product includes assessing a weight percent of a first volatile fatty acid and a weight percent of a second volatile fatty acid in a liquid mixture having volatile fatty acids from the organic waste product. The weight percent of the volatile fatty acids is based on the total weight of the carboxylic acids in the liquid mixture, the total weight of volatile fatty acids in the liquid mixture, or the total weight of lactic acid and volatile fatty acids in the mixture. A ratio of the weight percent of the first volatile fatty acid to the weight percent of the second volatile fatty acid in the liquid mixture is adjusted to yield a modified liquid mixture. The modified liquid is combined with polyhydroxyalkanoate-producing bacteria to yield a polyhydroxyalkanoate copolymer; and the polyhydroxyalkanoate copolymer is extracted from the polyhydroxyalkanoate-producing bacteria.

The present invention provides a method for extracting polyhydroxyalkanoates (PHAs), which comprises a pre-process step and an extraction step: removing water from waste sludge containing microorganisms in the pre-process step so that the waste sludge containing microorganisms has a water content of less than 40%; and applying a high-voltage pulsed electric field to the waste sludge during the extraction step to destroy the microorganisms and release the PHAs, wherein the high-voltage pulsed electric field is between 50 volts and 400 volts, an application time of the high-voltage pulsed electric field is between 5 seconds and 90 seconds, and an application frequency of the high-voltage pulsed electric field is between 500 Hz and 1000 Hz, thereby extracting the PHAs in the case of few chemicals.

The present invention provides a method for extracting polyhydroxyalkanoates (PHAs), which comprises a pre-process step and an extraction step: removing water from waste sludge containing microorganisms in the pre-process step so that the waste sludge containing microorganisms has a water content of less than 40%; and applying a high-voltage pulsed electric field to the waste sludge during the extraction step to destroy the microorganisms and release the PHAs, wherein the high-voltage pulsed electric field is between 50 volts and 400 volts, an application time of the high-voltage pulsed electric field is between 5 seconds and 90 seconds, and an application frequency of the high-voltage pulsed electric field is between 500 Hz and 1000 Hz, thereby extracting the PHAs in the case of few chemicals.

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.

A continuous process for preparing a polyester shrinkable film includes: pumping an amorphous PET-based polyester melt having a melt viscosity 1 directly from a polymerization reactor into a first cooling zone; cooling the polyester melt to increase the melt viscosity thereof to a melt viscosity 2 such that a difference between 2 and 1 ranges from 1500 poise to 3500 poise; feeding the polyester melt into a second cooling zone; cooling the polyester melt to increase the melt viscosity thereof to a melt viscosity 3 ranging from 5000 poise to 12000 poise such that a difference between 3 and 2 ranges from 1000 poise to 5500 poise; and pumping the polyester melt from the second cooling zone into a zone for film-forming treatment.