A process for the enzyme-catalyzed preparation of prepolymers for the production of plastics, based on an enzyme-catalyzed polymerization of monomer or oligomer compounds in a single phase aqueous solution, as well as the separation of the prepolymers precipitated therefrom and their subsequent use for the production of plastics and plastic articles obtainable therefrom. In particular, the invention relates to respective methods for enzyme-catalyzed preparation of prepolymers with polyamide-type bonding structure for the production of polyamide-based plastics.

A solid crosslinked polyester composition is disclosed wherein the crosslinked polyester is environmentally degradable in less than about 180 days. The crosslinked polyester is the polyesterification reaction product between one or more multi-hydroxylic alcohols, one or more hydroxy acids, and one or more multi-carboxylic acid compounds. Alternately, the crosslinked polyester is the polyesterification reaction product between one or more multi-hydroxylic alcohols, one or more hydroxy acids, one or more multi-carboxylic acid compounds, and a cyclic ester.

A solid crosslinked polyester composition is disclosed wherein the crosslinked polyester is environmentally degradable in less than about 180 days. The crosslinked polyester is the polyesterification reaction product between one or more multi-hydroxylic alcohols, one or more hydroxy acids, and one or more multi-carboxylic acid compounds. Alternately, the crosslinked polyester is the polyesterification reaction product between one or more multi-hydroxylic alcohols, one or more hydroxy acids, one or more multi-carboxylic acid compounds, and a cyclic ester.

A process can prepare a bio-resorbable polyester as a granulate or powder by bulk polymerization of one or more monomer(s). The process involves a) filling a monomer granulate, containing the one or more monomer(s), into a container; b) adding a polymerization catalyst and a chain length moderator on top of the monomer granulate; c) adding further monomer granulate on top; d) closing the container; e) carrying out a polymerization reaction in the closed container at a temperature in the range of 50° C. to 170° C., wherein a solid polymer in the form of a polymer block is formed; f) removing the polymer block from the container; and g) comminuting the polymer block to a granulate or powder; wherein the container is an unstirred container, wherein steps b) and c) are carried out once or are repeated, and wherein steps a) to e) are carried out under inert atmosphere.

Compounds can be used as catalysts, particularly in ring-opening polymerization reactions, including ring-opening co-polymerization (ROCOP) reactions, or in isocyanate trimerization reactions. The compounds have the formula L-M-X.sub.n, where L is a pyridyl-bis(iminophenolate) ligand, M is a metal ion, X is a co-ligand to balance the charge of the compound, and n is an integer from 0 to 7. The compounds can be prepared by base condensation of a pyridyl-diamine compound with an aldehyde or ketone.

Disclosed is a copolymer of polyglycolide and one or more additives. The copolymer may have a weight-average molecular weight (Mw) in the range of 10,000-1,000,000 and a ratio of a weight-average molecular weight to a number-average molecular weight (Mw/Mn) in the range of 1.0 to 10.0. The copolymer may have a melt index (MFR) in the range of 0.1 to 1000 g/10 min. The copolymer has good mechanical properties, thermal stability and hydrolytic stability. Also provided is a process for preparing the copolymer.

Provided is a process for producing a product having polyglycolic acid and glycolide from methyl glycolate. The process comprises esterification, polycondensation and optimization. Also provided are a product produced by the process and a method of changing the amount of the polyglycolic acid in the product by modifying the amount of an esterification catalyst and/or adjusting the reaction temperature.

This invention relates to a curable coating composition comprising: I. at least one acetoacetate functional polyester further comprising the residues of a. a hydroxyl component comprising: i. a diol in an amount ranging from 70 to 100 mole %, based on the total moles of (i) and (ii); and ii. a polyol in an amount ranging from 0 to 30 mole %, based on the total moles of (i) and (ii); b. a carboxyl component comprising a polycarboxylic acid compound, a derivative of polycarboxylic acid compound, or a combination thereof; and c. an alkyl acetoacetate, a diketene, or a combination thereof in an amount ranging from about 5 to about 50 weight %, based on the total weight of (a), (b), and (c). II. a curing agent having two or more aldehyde functional groups, and III. a basic catalyst.

This invention relates to a curable coating composition comprising: I. at least one acetoacetate functional polyester further comprising the residues of a. a hydroxyl component comprising: i. a diol in an amount ranging from 70 to 100 mole %, based on the total moles of (i) and (ii); and ii. a polyol in an amount ranging from 0 to 30 mole %, based on the total moles of (i) and (ii); b. a carboxyl component comprising a polycarboxylic acid compound, a derivative of polycarboxylic acid compound, or a combination thereof; and c. an alkyl acetoacetate, a diketene, or a combination thereof in an amount ranging from about 5 to about 50 weight %, based on the total weight of (a), (b), and (c). II. a curing agent having two or more aldehyde functional groups, and III. a basic catalyst.

The method is described herein for forming a polymer, comprising providing a first monomer comprising a polyol having at least two hydroxyl groups; providing a second monomer comprising a polyalkyl ester of a polycarboxylic acid having at least two alkyl ester groups; mixing the first monomer and the second monomer to form a reaction mixture; and reacting the first monomer and the second monomer in the mixture by transesterification to form a polyester polymer, which may, if desired be crosslinked. The polymers may also be copolymerized with other monomers. Polymers and copolymers formed from the method herein, as well as articles formed therefrom are also described. Such polymers and articles may be biocompatible and/or bioresorbable.