A PLG copolymer material, termed a PLG(p) copolymer material, adapted for use in a controlled release formulation for a bioactive material is provided, wherein the formulation exhibits a reduced initial burst effect when introduced into the tissue of a patient in need thereof. A method of preparation of the PLG copolymer material is also provided, as are methods of use.

A PLG copolymer material, termed a PLG(p) copolymer material, adapted for use in a controlled release formulation for a bioactive material is provided, wherein the formulation exhibits a reduced initial burst effect when introduced into the tissue of a patient in need thereof. A method of preparation of the PLG copolymer material is also provided, as are methods of use.

Compositions of P4HB with high purity have been developed. The compositions are prepared by washing P4HB biomass prior to solvent extraction, and precipitating P4HB from solution. The same solvent is preferably used to wash the P4HB biomass, and as a non-solvent to precipitate the polymer from a P4HB solvent solution. The highly pure P4HB compositions are suitable for preparing implants. The implants may be used for the repair of soft and hard tissues.

Compositions of P4HB with high purity have been developed. The compositions are prepared by washing P4HB biomass prior to solvent extraction, and precipitating P4HB from solution. The same solvent is preferably used to wash the P4HB biomass, and as a non-solvent to precipitate the polymer from a P4HB solvent solution. The highly pure P4HB compositions are suitable for preparing implants. The implants may be used for the repair of soft and hard tissues.

Methods according to the present invention decolorize a polymer by mixing a solution of the polymer with a photocatalyst and exposing the mixture to ultraviolet light; by way of non-limiting example, the polymer may be a star polymer and the photocatalyst may be titanium dioxide. Methods according to the present invention also utilize a metal scavenger, in some embodiments a solid-phase metal scavenger, to remove a metal catalyst from a polymer solution; by way of non-limiting example, the metal catalyst may be a tin catalyst. The decolorization methods and the catalyst removal methods of the present invention may be practiced separately, sequentially in any order, or simultaneously.

A method for purifying polybutylene terephthalate (PBT) includes: providing or receiving initial PBT, in which oligomers and tetrahydrofuran are present; dissolving the initial PBT in hexafluoroisopropanol (HFIP) to form a solution, in which the oligomers are also dissolved in the HFIP; and contacting the solution with compressed CO.sub.2 at a temperature and a pressure, thereby precipitating the purified PBT, resulting from a large portion of the oligomers are still dissolved in the HFIP, in the operation the temperature is in a range of 20 C. to 35 C., and the pressure is in a range of 900 psi to 1400 psi. A device for purifying PBT is also provided.

The present invention relates to a process for reducing volatiles in a polymer melt feed. The present invention also relates to a devolatilization apparatus for removing volatiles from a polymer melt feed.

The present invention relates to a process for reducing volatiles in a polymer melt feed. The present invention also relates to a devolatilization apparatus for removing volatiles from a polymer melt feed.

Method for recovering polyesters and polyamides from the corresponding polymeric waste products, comprising the following steps: a) Depolymerization of the polyester/polyamide and obtaining the linear and/or cyclic oligomers and/or monomers, b) Recovery and purification of the products from step a), c) Polymerization of the product from step b) by polycondensation and/or ring opening polymerization.

In step a) the depolymerization is partial and results in a mixture of oligomers, comprising especially cyclic oligomers and said step is conducted in a polar and/or apolar aprotic solvent at the temperature near solvent boiling temperature, between 100 and 300? C. and in the presence of a catalyst, simultaneously distilling the reaction solvent and the volatile by-products dissolved therein.

The present invention is directed to polymers and copolymers, and systems and methods for processing the same. Advantageously, the polymers and copolymers of the present invention have undergone processing in a falling strand devolatilizer and rotary disk finisher such that a low-cost, low-energy, and high-production-rate product is produced.