Abstract: Monomer addition methodology is provided to adjust monomer addition rates to a polymerization reactor. Advantages of the invention include control of bioabsorbable copolymer structure, improvement of monomer conversion, control of reaction temperature, and reduced reaction time. The overall result is an improved process and enhanced product performance. The technology is particularly useful in the copolymerization of monomers with different reactivity ratios, such as glycolide/lactide copolymers and glycolide/caprolactone copolymers. Monomer reactivity ratios and reaction kinetics are utilized to adjust monomer addition rates.

Abstract: The present invention includes photocurable, liquid polymers incorporating coumarin ester endgroups into their molecular structure, which polymers are crosslinked upon irradiation with ultraviolet light by photochemically allowed [2+2] cycloaddition reactions among the chain ends, and which crosslinked polymers are useful in the preparation of medical devices, tissue engineering scaffolds, drug delivery systems and, in particular, in vivo preparation of implants in an open surgical procedure or laproscopically.

Abstract: A block copolymer is disclosed, which comprises a first block comprising polymerized units of an alkylene oxide and a second block comprising polymerized units of an alkylene oxide and a lactone, said copolymer being obtainable by polymerizing an alkylene oxide in the presence of an organic initiator to form said first block, and reacting the first block with a mixture of an alkylene oxide and a lactone. Such copolymers are found to have improved foam inhibition characteristics while maintaining their biodegradable properties.

Abstract: Disclosed is a method for preparing a biodegradable polymer in the form of uniform powder or spherical particles by dispersion polymerization without a grinding step. The method for preparing a biodegradable polyester includes dispersing a monomer in the presence of a catalyst in a dispersion solvent to form a solid or liquid phase for dispersion polymerization and thereby to yield a biodegradable aliphatic polyester in the form of spherical particles or powder, the monomer comprising a mixture of a first compound (e.g., lactide or glycolide) and a second compound being selected from the group consisting of polyhydric alcohols (e.g., glycerin, erythritol, penterythritol or dipentaerythritol) and carprolactone. The present invention readily prepares a biodegradable polymer having a high molecular weight in the form of uniform powder or spherical particles.

Abstract: An absorbable crystalline, monocentric polyaxial copolymer comprising a central carbon or nitrogen atom and at least three axes, each of which includes an amorphous flexible component adjacent and originating from the central atom and a rigid, crystallizable component extending outwardly from the amorphous, flexible component is disclosed along with the use of such copolymer in medical devices which may contain a bioactive agent. The present invention also relates to a suture, stents, stent mantles and sealing devices made from the polyaxial copolymer.

Abstract: The present invention includes photocurable, liquid polymers incorporating coumarin ester endgroups into their molecular structure, which polymers are crosslinked upon irradiation with ultraviolet light by photochemically allowed [2+2] cycloaddition reactions among the chain ends, and which crosslinked polymers are useful in the preparation of medical devices, tissue engineering scaffolds, drug delivery systems and, in particular, in vivo preparation of implants in an open surgical procedure or laproscopically.

Abstract: The present invention uses a reactor that combines devices having a special portion structure to solve the difficulty of uniform blending due to the reactants becoming highly viscous, the difficulty of heat removal, and the increase in pressure loss, thus leading to continuous production of a polyester-based polymer stably having excellent quality.

Abstract: Copolymers of lactide and glycolide with high glycolide content. The average glycolate block length is less then about 3, which allows the copolymer to be soluble in slightly polar solvents such as methylene chloride.

Abstract: An absorbable crystalline, monocentric polyaxial copolymer comprising a central carbon or nitrogen atom and at least three axes, each of which includes an amorphous flexible component adjacent and originating from the central atom and a rigid, crystallizable component extending outwardly from the amorphous, flexible component is disclosed along with the use of such copolymer in medical devices which may contain a bioactive agent. The present invention also relates to a suture, stents, stent mantles and sealing devices made from the polyaxial copolymer.

Abstract: The present invention is generally directed to a process for producing lactide-based polymers and the polymers produced by this process. The polymers of the present invention are terpolymers formed by the copolymerization of a lactide monomer, a linking monomer and an epoxy-terminated monomer. In one embodiment of the invention, the polymers may be formed from fluorine-containing monomers or aromatic ring-containing monomers. The disclosed materials may display improved hydrolytic and thermal characteristics as compared to previously known lactide-based materials. For example, the lactide based terpolymers may have a glass transition temperature over 60° C. For instance, lactide-based thermoplastic terpolymers of the present invention can have a glass transition temperatures of about 80° C. or higher. Lactide-based thermoset networks of the invention can have glass transition temperatures of up to about 200° C.

Abstract: An absorbable crystalline, monocentric polyaxial copolymer comprising a central carbon or nitrogen atom and at least three axes, each of which includes an amorphous flexible component adjacent and originating from the central atom and a rigid, crystallizable component extending outwardly from the amorphous, flexible component is disclosed along with the use of such copolymer in medical devices which may contain a bioactive agent. The present invention also relates to a suture, stents, stent mantles and sealing devices made from the polyaxial copolymer.

Abstract: A process for producing a lactic acid polymer of 15,000 to 50,000 in weight-average molecular weight, the content of polymeric materials having not more than about 5,000 in weight-average molecular weight therein being not more than about 5% by weight, characterized by hydrolyzing a high molecular weight lactic acid polymer, placing the resultant solution comprising the hydrolyzed product under a condition capable of precipitating the objective lactic acid polymer, separating the precipitated lactic acid polymer and collecting them. The lactic acid polymer is useful as a matrix for sustained-release preparations. The sustained-release microcapsule preparation encapsulating a physiologically active substance can fully prevent the initial excessive release of the physiologically active substance from the microcapsules and keep a stable release rate over a long period of time.

Abstract: In polymerizing biodegradable polymer material, a compressed gas is used as a reaction solvent for a solution-polymerization, in order to prepare biodegradable polyester homopolymer and copolymer with a high molecular weight in a fine powder form with a particle size of 0.01˜1000 ?m.

Abstract: Compositions based on ?-caprolactone polymer, comprising at least one ?-caprolactone polymer and calcium carbonate. Process for preparing these compositions, which are used for manufacturing articles, in particular films, preferably obtained by extrusion blow-moulding or by flat-die extrusion.

Abstract: In the present invention, there are obtained aliphatic polyesters having a controlled thermal decomposing property, hydrolizability, and biodegradability, in which OH terminals and COOH terminals are decreased to 50% and 30%, respectively, through a ring-opening polymerization of a lactone and lactide by a mono alcohol having a high boiling point or a metal alkoxide, or by further decreasing both terminals through combining produced polymer terminals with a diisocyanate and, from a composition containing the polyesters, there is obtained a particle-state composition for agriculture and gardening in which a duration period of a fertilizing effect can be controlled, and which is not remained in soil by decomposition.

Abstract: The present invention is directed to a process for making an absorbable polylactone copolymer prepared in part from about 2 to about 80 mole percent glycolide, which process utilizes a combination of a monofunctional polymerization initiator and a di-functional polymerization initiator, to achieve rates of crystallization of the copolymer of at least about 2 times faster than the rate of crystallization of a copolymer made by a similar process utilizing either the mono-functional or the di-functional polymerization initiator alone. Absorbable polylactone copolymers prepared by such processes and medical devices containing such copolymers are also disclosed.

Abstract: The object of the present invention is to provide a novel method for effectively producing a cyclic lactic acid oligomer, and a cyclic lactic acid oligomer produced by the method.

Abstract: Hyperbranched polymers are prepared by a process in which a monomer having the form Ax is reacted with another monomer of the form By, where A and B are functional groups that do not react with themselves, but do react with each other. The process allows synthesis of hyperbranched polymers having a single type of terminal functional group from comonomers, each of which has a single type of functional group. The invention allows greater flexibility in the preparation of a larger variety of different hyperbranched polymers and enables hyperbranched polymers to be prepared at a lower cost as compared with conventional processes using monomers having two types of functional groups that react during polymerization.

Abstract: Chemically different cyclic ester oligomers can be copolymerized to form copolyesters whose properties can be tailored by the choice of cyclic ester oligomers used. The copolyesters formed are especially useful as encapsulants and as coatings. In many instances the copolyesters, assuming they are not randomized in later transesterification reactions, have unique microstructures related to the sequencing of repeat units the their polymer chains.

Abstract: The present invention is directed to absorbable polylactone copolymers prepared in part from about 2 to about 80 mole percent glycolide, utilizing a combination of a monofunctional polymerization initiator and a di-functional polymerization initiator, to achieve rates of crystallization of the copolymer of at least about 2 times faster than the rate of crystallization of a copolymer made by a similar process utilizing either the mono-functional or the di-functional polymerization initiator alone. Medical devices containing such copolymers are also disclosed.

Abstract: An absorbable crystalline, monocentric polyaxial copolymer comprising a central carbon or nitrogen atom and at least three axes, each of which includes an amorphous flexible component adjacent and originating from the central atom and a rigid, crystallizable component extending outwardly from the amorphous, flexible component is disclosed along with the use of such copolymer in medical devices which may contain a bioactive agent. The present invention also relates to a suture, stents, stent mantles and sealing devices made from the polyaxial copolymer.

Abstract: This invention provides a hydroxyalkyl(meth)acrylate composition modified by a small amount of lactones in which a proportion of monomers having two or more continuous chains of lactone is less than 50% (area % by GPC). This invention also provides methods for synthesizing such a composition. This invention also provides an acrylic polyol resin comprising the hydroxyalkyl(meth)acrylate composition, a carboxylic group-containing acrylate composition modified by a small amount of lactones, and a polyester unsaturated monomer modified by a small amount of lactones. Uses of these materials in curable resins, coating compositions, and finishing agents are also provided.

Abstract: A bromine-containing, hydroxy-functional copolymer is prepared from an initiator that is solid at room temperature and has at least one bromine atom. The initiator is reacted with an effective amount of lactone monomers, optionally in the presence of a catalyst, to establish a bromine-containing, hydroxy-functional copolymer that is a liquid at room temperature. The copolymer of this invention may be used as liquid reactive flame retardant and, in the event the copolymer is polyfunctional, as a crosslinker.

Abstract: The present invention relates in general to implantable, resorbable copolymers containing L-lactide and glycolide repeat units, and in particular to terpolymers containing L-lactide, glycolide, and one other type of repeat unit selected from the group consisting of D-lactide, D,L-lactide, and &egr;-caprolactone. Medical devices for in vivo implantation applications containing such implantable, resorbable copolymers are also described, as well as methods for making such copolymers and devices.

Abstract: The present invention is directed to a method for reducing waste accumulation by using an environmentally degradable disposable material. The disposable material, which includes a hydroxycarboxylic acid-containing polymer, degrades hydrolytically during operative and disposal stages in a controlled manner such that the disposal degradation rate of the material is accelerated relative to the operative degradation rate of the material.

Abstract: The invention relates to novel absorbable polyesters, produced by ring-opening polymerisation of hydroxycarboxylic acids in the presence of a polyol containing an electrolyte, in an extruder. In particular, the invention relates to novel polylactide glycolide polyesters which are essentially free of dextran sulphate and which are produced by ring-opening polymerisation of lactide and glycolide in the presence of dextran sulphate in the extruder; to the production of the same and to their use in depot medicaments.

Abstract: Copolymers of lactide and glycolide with high glycolide content. The average glycolate block length is less then about 3, which allows the copolymer to be soluble in slightly polar solvents such as methylene chloride.

Abstract: Disclosed are copolymers of cyclic esters, e.g., caprolactone, and cyclic formals of substituted or unsubstituted diols, e.g., 1,3-dioxepane. The copolymers can provide a low melting temperature rendering them liquids at room temperature. Elastomeric polyurethanes prepared from such copolymers can exhibit a low Tg transition and good resistance to hydrolysis and oxidation. The copolymers are particularly useful for elastomers, coatings, adhesives, inks or binders requiring low temperature flexibility and good resistance to hydrolysis and oxidation.

Abstract: The present invention is directed to a process for making an absorbable polylactone copolymer prepared in part from about 2 to about 80 mole percent glycolide, which process utilizes a combination of a monofunctional polymerization initiator and a di-functional polymerization initiator, to achieve rates of crystallization of the copolymer of at least about 2 times faster than the rate of crystallization of a copolymer made by a similar process utilizing either the mono-functional or the di-functional polymerization initiator alone. Absorbable polylactone copolymers prepared by such processes and medical devices containing such copolymers are also disclosed.

Abstract: Polylactic acid is produced from dimers of lactic acid in an energy saving manner by contacting a lactic acid source via an extraction membrane with an amine carrier solvent to extract lactic acid across the membrane. One or two membranes may be used. After extraction, the aminium lactate salt is crystallized, disassociated and purified.

Abstract: The invention relates to polycondensation resins which are prepared by polycondensation of compounds having a low molecular weight and separation of small molecules in the presence of at least one hetergeneous catalyst. The invention also relates to polyaddition resins which are prepared by polyaddition in the presence of at least one heterogeneous catalyst. The invention further relates to the use of said polycondensation resins and polyaddition resins for the preparation of moulded parts, adhesives and coating materials.

Abstract: The invention concerns a method for obtaining oxacarbonyl polymers comprising steps which consist in: providing at least monomers comprising at least a cyclic oxacarbonyl function, an initiator, and in polymerising or copolymerising said monomers, in bulk or in solution, the initiator being selected among bicyclic guanidine compounds of formula (I) or (II) wherein one and/or the other of the cycles can be substituted, in at least any one of positions 2, 3, 4, 8, 9 and 10 of formula (I) or in at least any one of positions 2, 3, 7 and 8 of formula (II), by at least a radical selected among the alkyl groups with 1 to 6 carbon atoms, the cycloalkyl groups with 5 to 7 carbon atoms, polystyrene hydrocarbon chains.

Abstract: In the present invention, there are obtained aliphatic polyesters having a controlled thermal decomposing property, hydrolizability, and biodegradability, in which OH terminals and COOH terminals are decreased to 50% and 30%, respectively, through a ring-opening polymerization of a lactone and lactide by a mono alcohol having a high boiling point or a metal alkoxide, or by further decreasing both terminals through combining produced polymer terminals with a diisocyanate and, from a composition containing the polyesters, there is obtained a particle-state composition for agriculture and gardening in which a duration period of a fertilizing effect can be controlled, and which is not remained in soil by decomposition.

Abstract: Syndiotactic poly(lactic acid) is formed by polymerization involving a cleavage of the same oxygen-acyl bond in a series of meso-lactide molecules to form polymer containing a series of units with stereocenters wherein adjacent stereocenters are of the opposite stereochemistry. The mechanism is catalyzed by chiral metal alkoxides that afford stereocontrol such as those formed by reacting or the opposite enantiomer with Al(OR)3 where R is straight chain or branched alkyl containing 1 to 20 carbon atoms, e.g., methyl or isopropyl, in solvent, with subsequent evaporation of solvent in vacuo.

Abstract: A bromine-containing, hydroxy-functional copolymer is prepared from an initiator that is solid at room temperature and has at least one bromone atom. The initiator is reacted with an effective amount of lactone monomers, optionally in the presence of a catalyst, to establish a bromine-containing, hydroxy-functional copolymer that is a liquid at room temperature. The copolymer of this invention may be used as liquid reactive flame retardant and, in the event the copolymer is polyfunctional, as a crosslinker.

Abstract: The present invention relates to biodegradable PHA copolymers comprising at least two randomly repeating monomer units. The present invention further relates to a plastic article comprising a biodegradable copolymer, wherein the biodegradable copolymer comprises at least two randomly repeating monomer units (RRMU) wherein the first RRMU has the structure wherein R1 is H, or C1 or C2 alkyl, and n is 1 or 2; the second RRMU has the structure and wherein at least 50% of the RRMUs have the structure of the first RRMU. The present invention further relates to an absorbent article comprising a liquid pervious topsheet, a liquid impervious backsheet comprising a film comprising a PHA of the present invention and an absorbent core positioned between the topsheet and the backsheet.

Abstract: The present invention is a water-responsive blend of a polylactide and a polyvinyl alcohol. The present invention includes films and personal care articles comprising a blend of a polyvinyl alcohol and a polylactide and includes a method of making such films and articles and a method of varying the water responsiveness of such films and articles. In a preferred embodiment, the compositions, films and articles comprise a blend of polyvinyl alcohol and modified polylactide. The compositions and films described herein are useful as a component in flushable and degradable articles.

Abstract: A stereospecific poly(lactic acid) is isotactic poly(lactic acid) having a number average molecular weight ranging from 10,000 to 200,000 grams per mole, with, on average, an equal number of poly (R) and poly (S) blocks where each block contains an average of 5 to 50 monomer units. Product was prepared by polymerizing rac-lactide in the presence of racemic catalyst consisting of: and the corresponding S-enantiomer or in the presence of racemic catalyst consisting of: and the corresponding S-enantiomer, wherein R is C1-C4 alkyl which is straight chain or branched.

Abstract: Hyperbranched polymers are prepared by a process in which a monomer having the form Ax is reacted with another monomer of the form By, where A and B are functional groups that do not react with themselves, but do react with each other. The process allows synthesis of hyperbranched polymers having a single type of terminal functional group from comonomers, each of which has a single type of functional group. The invention allows greater flexibility in the preparation of a larger variety of different hyperbranched polymers and enables hyperbranched polymers to be prepared at a lower cost as compared with conventional processes using monomers having two types of functional groups that react during polymerization.

Abstract: In the present invention, there are obtained aliphatic polyesters having a controlled thermal decomposing property, hydrolizability, and biodegradability, in which OH terminals and COOH terminals are decreased to 50% and 30%, respectively, through a ring-opening polymerization of a lactone and lactide by a mono alcohol having a high boiling point or a metal alkoxide, or by further decreasing both terminals through combining produced polymer terminals with a diisocyanate and, from a composition containing the polyesters, there is obtained a particle-state composition for agriculture and gardening in which a duration period of a fertilizing effect can be controlled, and which is not remained in soil by decomposition.

Abstract: A medical material which contains a lactide-containing polymer having weight-average molecular weight lower than 400000 as determined by GPC and has a lactide content of 4000 ppm or lower.

Abstract: The present invention relates to diblock copolymers and more particularly to polycaprolactone-b-polyethylene oxide (PCL-b-PEO) diblock copolymers used in micellar systems, for delivering a biologically active agent to a site There is provided a diblock copolymer compound comprising a hydrophilic block and a hydrophobic block, the hydrophilic block comprising a polyethylene oxide (PEO) polymer, the hydrophobic block comprising a polycaprolactone (PCL) polymer, the PCL polymer comprising a number of caprolactone monomers selected from 5 to 150, the PEO polymer comprising a number of ethylene oxide monomers selected from 30 to 100. The diblock copolymer compound of the present invention may be used to form a micellar delivery system for delivering biologically active agents such as lipophilic drugs to sites such as the central nervous system.

Abstract: The present invention relates to diblock copolymers and more particularly to polycaprolactone-b-polyethylene oxide (PCL-b-PEO) diblock copolymers used in micellar systems, for delivering a biologically active agent to a site. There is provided a diblock copolymer compound comprising a hydrophilic block and a hydrophobic block, the hydrophilic block comprising a polyethylene oxide (PEO) polymer, the hydrophobic block comprising a polycaprolactone (PCL) polymer, the PCL polymer comprising a number of caprolactone monomers selected from 5 to 150, the PEO polymer comprising a number of ethylene oxide monomers selected from 30 to 100. The diblock copolymer compound of the present invention may be used to form a micellar delivery system for delivering biologically active agents such as lipophilic drugs to sites such as the central nervous system.

Abstract: An absorbable crystalline, monocentric polyaxial copolymer comprising a central carbon or nitrogen atom and at least three axes, each of which includes an amorphous flexible component adjacent and originating from the central atom and a rigid, crystallizable component extending outwardly from the amorphous, flexible component is disclosed along with the use of such copolymer in medical devices which may contain a bioactive agent.

Abstract: A bromine-containing, hydroxy-functional copolymer is prepared from an initiator that is solid at room temperature and has at least one bromine atom. The initiator is reacted with an effective amount of lactone monomers, optionally in the presence of a catalyst, to establish a bromine-containing, hydroxy-functional copolymer that is a liquid at room temperature. The copolymer of this invention may be used as liquid reactive flame retardant and, in the event the copolymer is polyfunctional, as a crosslinker.

Abstract: The present invention is directed to a method for reducing waste accumulation by using an environmentally degradable disposable material. The disposable material, which includes a hydroxycarboxylic acid-containing polymer, degrades hydrolytically during operative and disposal stages in a controlled manner such that the disposal degradation rate of the material is accelerated relative to the operative degradation rate of the material.

Abstract: The present invention includes photocurable, liquid polymers incorporating coumarin ester endgroups into their molecular structure, which polymers are crosslinked upon irradiation with ultraviolet light by photochemically allowed [2+2] cycloaddition reactions among the chain ends, and which crosslinked polymers are useful in the preparation of medical devices, tissue engineering scaffolds, drug delivery systems and, in particular, in vivo preparation of implants in an open surgical procedure or laproscopically.

Abstract: Copolymers of lactide and glycolide with high glycolide content. The average glycolate block length is less then about 3, which allows the copolymer to be soluble in slightly polar solvents such as methylene chloride.

Abstract: This invention relates to a method of polymerization of lactide or glycolide (GA) monomers and in particular to a method of polymerizing one type of the monomers or two types of the monomers using alkyl aluminum catalyst to proceed with bulk or solution polymerization to prepare biodegradable homopolymers or copolymers, and high-molecular-weight homopolymers of polylactide (PLA), polyglycolide (PGA), or copolymers of lactide/glycolide prepared thereof.

Abstract: Copolymers of lactide and glycolide with high glycolide content. The average glycolate block length is less then about 3, which allows the copolymer to be soluble in slightly polar solvents such as methylene chloride.