Abstract: In a process for the preparation of poly-o-hydroxyamides and poly-o-mercaptoamides, a bis-o-aminophenol or a bis-o-aminothiophenol is reacted at a temperature of .ltoreq.0.degree. C. with a mixed dianhydride of a dicarboxylic acid and a sulfonic acid with the following structure:E--SO.sub.2 --O--CO--R*--CO--O--SO.sub.2 --Ewhere E is an (optionally substituted) methyl, phenyl, or naphthyl group and R* is the parent body of the dicarboxylic acid.

Abstract: There is provided a method for easily preparing a polyhydroxycarboxylic acid resin in a one pot reaction by adding 1,3-substituted-1,1,3,3-tetraorganodistanoxan as a polymerization catalyst to a hydroxycarboxylic acid, such as L-lactic acid containing 10 to 50% of water as a starting material, and stirring while heating under a reduced pressure condition or in an organic solvent.

Abstract: A process for the preparation of macromonomers by reaction between a lactone and a hydroxyalkylacrylate in the presence of >200 ppm phosphoric acid catalyst is provided. The reaction takes place in the presence of a free radical inhibitor at a temperature of from 100.degree. to 130.degree. C. Preferably, the lactone is .epsilon.-caprolactone and the hydroxyalkylacrylate is selected from the group consisting of 2-hydroxyethylacrylate and 2-hydroxyethylmethacrylate.

Abstract: Poly-p-dioxanone is prepared in a process comprising:(a) heating a reaction mixture comprising p-dioxanone and an effective amount of a polymerization catalyst under conditions of temperature and pressure effective to produce a reaction product mixture comprising molten poly-p-dioxanone and unreacted p-dioxanone;(b) solidifying the reaction product mixture and dividing it into a plurality of solid particles;(c) introducing the solid particles into a separator vessel and exposing the solid particles to a temperature within the range of about 25.degree. to about 110.degree. C. under reduced pressure and sweeping the particles with an inert gas, thereby separating the reaction product mixture into an unreacted p-dioxanone portion and a poly-p-dioxanone portion comprising less than about 3 weight percent p-dioxanone; and(d) removing the poly-p-dioxanone portion from the separator.The invention process permits the economical production of high molecular weight poly-p-dioxanone in the melt.

Abstract: Medical devices or components for medical devices formed from bioabsorbable elastomers comprising a random copolymer are disclosed. The random copolymer is a copolymer of from about 30 to about 70 weight percent of: a) .epsilon.-caprolactone, trimethylene carbonate, an ether lactone, or a mixture of these, and b) the balance being substantially glycolide, para-dioxanone, or a mixture of these. The random copolymers surprisingly exhibit elastomeric properties, and the copolymers are bioabsorbable. The combination of physical and biological properties of these elastomeric copolymers are particularly well-suited for numerous medical and surgical applications.

Abstract: Preventive as well as therapeutic treatment to alleviate cosmetic conditions and symptoms of dermatologic disorders with amphoteric compositions containing alpha hydroxyacids, alpha ketoacids, related compounds or polymeric forms of hydroxyacids is disclosed. The cosmetic conditions and the dermatologic disorders in which the amphoteric compositions and the polymeric compounds may be useful include dry skin, dandruff, ache, keratoses, psoriasis, eczema, pruritus, age spots, lentigines, melasmas, wrinkles, warts, blemished skin, hyperpigmented skin, kyperkeratotic skin, inflammatory dermatoses, skin changes associated with aging, and skin requiring cleansers.

Abstract: A crystalline polylactone is produced having reactive acrylate end groups. When incorporated into a thermosetting resin which includes reactive C.dbd.CH.sub.2 sites, the present functionalized polylactone acts as a toughener, greatly increasing the impact resistance of the final cured product. Also disclosed are carboxyl-bearing polylactones as tougheners for epoxy resin systems.

Abstract: The invention discloses methods of preparing copolymers from norbornene-type monomers and cationically polymerizable monomers or polymers from catalytically polymerizable monomers by employing Group VIII transition metal ion source in a solvent for said monomers at a temperature in the range from -100.degree. C. to 120.degree. C. Also disclosed are copolymers from norbornene-type monomers and catalytically polymerizable monomers.

Abstract: A method of treating a polymer involves contacting the polymer with a supercritical fluid under conditions of temperature and pressure to incorporate the supercritical fluid in the polymer and thereby effectuate an increase in plasticity and/or elasticity of the polymer. In a particular embodiment, the treated polymer is a biocompatible polymer which is fabricated into a medical device or part thereof.

Abstract: A new class of polymers include repeating units comprising one or more arylene units substituted with heterocyclic side groups. The heterocyclic substituted arylene repeat units have the general structural formula: ##STR1## wherein Het is a heterocyclic group, R is an optional substituent, x is 1 or 2, and y is less than or equal to 4-x.

Abstract: Acrylate monomers such as methyl methacrylate, or other suitable monomers such as lactams, lactones, or acrylamides, are polymerized by reaction injection molding (RIM) utilizing a combination of organo group-4 catalysts, e.g., a neutral organo catalyst and a cationic organo catalyst. Preferably a Lewis acid is utilized which reacts with the neutral organo catalyst and forms in situ the cationic organo catalyst. Significant exotherms are rapidly generated and result in short cure times and typically in high conversions of at least 95 percent by weight of the monomer. The catalysts of the present invention give good control of tacticity and thus high Tg polymers such as syndiotactic methyl methacrylate can be produced.

Abstract: Poly-.epsilon.-caprolactones are produced by continuous polymerization of .epsilon.-caprolactone as a melt in an extruder (reactive extrusion) with the use, as polymerization initiator, of aluminium trialkoxides in which at least one alkoxy radical includes at least one other oxygen atom besides the oxygen atom constituting the aluminoxane (AI--O) bond. This oxygen atom is advantageously present in the form of an ester or ether functional group. These initiators are generally in the liquid state at ambient temperature and are furthermore miscible with .epsilon.-caprolactone, with the result that they can be used in the absence of solvent. The appropriate adjustment of the feed flow rates of .epsilon.-caprolactone and of initiator to the extruder permits the manufacture of custom-made poly-.epsilon.-caprolactones which have predesigned weight-average molecular masses.

Abstract: Poly-p-dioxanone is prepared in a process comprising:(a) heating a reaction mixture comprising p-dioxanone and an effective amount of a polymerization catalyst under conditions of temperature and pressure effective to produce a reaction product mixture comprising molten poly-p-dioxanone and unreacted p-dioxanone;(b) adding to said reaction product mixture a cyclic anhydride under conditions effective for reaction of the poly-p-dioxanone with the cyclic anhydride to form an end-capped poly-p-dioxanone;(c) exposing the reaction product mixture to a temperature within the range of about 50 to about 150.degree. C. under reduced pressure and removing unreacted p-dioxanone from the reaction product mixture; and(d) recovering the end-capped poly-p-dioxanone.The invention process permits the economical production of high molecular weight poly-p-dioxanone in the melt.

Abstract: The present invention relates to a method of preparing a polyester comprising polymerizing at least one .beta.-substituted-.beta.-propiolactone in the presence of an initiating amount of alkylzinc alkoxide in bulk or in solvent for a reaction time and temperature sufficient to produce said polyester.

Abstract: Polymer compositions are provided which comprise a first polyhydroxyalkanoate component and optionally a second polymer component, the composition have enhanced properties by using an inorganic oxygen containing compound in the composition. The inorganic oxygen containing compound may be acting as a transesterification catalyst.

Abstract: Absorbable, segmented copolymers of aliphatic polyesters based on lactone monomers glycolide, and p-dioxanone are described. The segmented copolymers exhibit a broad range of properties, especially high strength and stiffness, and fast absorption rates and breaking strength retention (BSR) profiles, useful in a variety of medical devices. Most importantly, for suture applications where Vicryl.RTM.-like polyglcolide-polylactide sutures with excellent tensile properties, but shorter BSR profiles than Vicryl.RTM. are needed. The copolymers of the present invention have such properties, making them useful in plastic surgery where faster absorption times would lead to less tissue scarring.

Abstract: The invention relates to a substantially solventless curable resin composition, in particular for the fabrication of prepregs, which contains more than 45% by weight of substances which are solid at ambient temperature at least or at lower temperature, and which, in addition to comprising customary modifiers, comprises solid epoxy resins or a mixture of liquid and solid epoxy resins, at least one initiator which is sensitive to UV radiation for the polymerisation of the epoxy resins and has the formula I ##STR1## wherein a and b are each independently of the other 1 or 2, R.sup.1 ist a .pi.-arene, R.sup.2 is a .pi.-arene, an indenyl anion or a cyclopentadienyl anion, [X].sup..crclbar. is an anion [LQ.sub.m ].sup..crclbar.

Abstract: A composition comprising a polylactide polymer with improved extensional viscosity and methods of making the same are disclosed. The polylactide polymer composition is prepared by providing in the composition polylactide polymer molecules which have been modified, relative to linear non-substituted polylactide, to provide increased molecular interaction among polylactide backbone chains in the composition. The preferred polylactide polymer composition has a number average molecular weight of at least about 10,000 (preferably at least 50,000) and a polydispersity of at least about 2.5. In addition, the polylactide polymer composition should have a neck-in ratio of less than about 0.8.

Abstract: The invention relates to the use of copolymers of racemic lactide and .epsilon.-caprolactone, .delta.-valerolactone, gamma-decalactone or .beta.-hydroxybutyric acid, prepared by the reaction of the monomers in the molar ratio of lactide to reaction partner of approximately 95-70 to 5-30, with the addition of metal carboxylates, known per se, as initiators at temperatures of approximately 150.degree. C. over a period of time of approximately 16 to 18 hours, for the topical treatment of human or animal skin.

Abstract: A process for producing polylactic acid includes the steps of polycondensing lactic acid to a lactic acid prepolymer having a weight-average molecular weight of 10,000-50,000 in a batch-type polymerization reactor, and polycondensing the lactic acid prepolymer to lactic acid polymer having a weight-average molecular weight of at least 100,000 by means of a screw-type extruder.

Abstract: Disclosed are a lactone polymer, a carbonate polymer, a lactone-carbonate random or block copolymer which are mono-dispersed, that is, which have a molecular weight distribution of nearly 1, or, in which purity of a polymer component having a unitary structure is very high, and processes for the preparation thereof which comprise a ring-opening addition reaction of a lactone monomer and/or a cyclic carbonate monomer with a ring-opening initiator in the presence of an organic aluminum-based Lewis acid represented by general formula (I), ##STR1## wherein R is an alkyl group having a carbon number ranging from 1 to 4, Y is independently selected from a substituted group, and p is any one of 1, 2 and 3.

Abstract: Poly(lactic acid) with a high molecular weight is produced by the polycondensation reaction of the free monomer carried out in the presence of a catalytically effective quantity of iron ions. High molecular weight poly(lactic acid) and lactide are obtained as the principal products.

Abstract: A lactide polymer composition combining compositional and purity limitations and catalyst optimization or addition of stabilizing agents resulting in a melt-stable polymer is disclosed. The melt-stable lactide polymer comprises a plurality of polylactide polymer chains, residual lactide in concentration of less than 2 percent and water in concentration of less than 1000 parts-per-million. A stabilizing agent in an amount sufficient to reduce depolymerization of the lactide polymer during melt-processing or alternatively, control of catalyst level at a molar ratio of monomer to catalyst greater than 3000:1 is also included in the melt-stable composition. A process for manufacture of a melt-stable lactide polymer composition includes polymerizing a lactide mixture and adding stabilizing agents sufficient to reduce depolymerization of the polylactide during melt-processing, followed by devolatilizing the polylactide to remove monomer and water.

Abstract: The biodegradability of polyglycol-based block copolymers is improved by including in the copolymer a lactone. Representative of these biodegradable enhanced copolymers are those made of 1,2-butylene oxide and .epsilon.-caprolactone capped with a homopolymer block of ethylene oxide. The copolymers of this invention have many uses, such as nonionic surfactants, foam control agents, lubricants, and the like.

Abstract: An integrated process for the manufacture of lactide from a solution of lactic acid in de-ionized water comprising the sequential steps:A. Dehydrating the aqueous lactic acid in at least two stages to effect condensation polymerization of the lactic acid and the formation of oligomers in which the average number of monomer units is 8-25, the dehydration stages being conducted in equipment fabricated from low ferrous materials;B. Thermally cracking the oligomers in the presence of depolymerization catalyst to form lactide vapor of which the average residence time within the cracking zone is less than 15 seconds;C. Condensing the lactide vapor and fractionally distilling the condensate to remove concentrated lactide as a liquid sidestream; andD. Subjecting the concentrated lactide sidestream to melt crystallization to separate purified lactide having an Acidity Potential less than 6.

Abstract: A biodegradable, optically active copolymer is disclosed. The copolymer is represented by general formula (I): ##STR1## wherein R.sup.1 represents a group selected from the group consisting of methyldimethylene, 1,2-dimethyldimethylene, 1,1-dimethyldimethylene, methyltrimethylene, tetramethylene, methyltetramethylene, pentamethylene, 1,4-dimethyl-2-oxo-3-oxytetramethylene, 2-oxo-3-oxytetramethylene, and 2-methyl-3-oxypentamethylene, and m and n each represents a natural number of from 10 to 15,000. According to the present invention, useful polymers which are a new type of functional materials characterized as having optical activity, biodegradability (enzymatic degradability), and hydrolyzability can be easily produced in an industrially advantageous manner by the ring-opening copolymerization of optically active .beta.-butyrolactone with various lactones.

Abstract: A preparation process of polyhydroxycarboxylic acid having an inherent viscosity of 0.3 dl/g or more by dehydrating polycondensation of lactic acid containing hydroxycarboxylic acid in an organic solvent in the presence or absence of a catalyst, comprising using a hydroxycarboxylic acid raw material which comprises one or more impurities selected from the group consisting of methanol, ethanol, acetic acid, pyruvic acid, fumaric acid, methyl lactate, ethyl lactate and butyl lactate in a total amount of 0.3% by mole or less for the amount of said hydroxycarboxylic acid raw material.

Abstract: Alcohol-soluble aromatic heterocyclic polymers and copolymers having repeating units of the formulae I or II: ##STR1## wherein Q is a benzobisazole of the formula: ##STR2## wherein X is --O-- or --S--; wherein x has a value of 0.0 to 1.00 and y has a value of 0.05 to 1.00, and R is selected from the group consisting of: ##STR3## and R' is selected from the group consisting of alkyl having 1 to 5 carbon atoms, alkaryl having 7 to 12 carbon atoms, aralkyl having 7 to 12 carbon atoms and substituted aromatic having 1 to 3 substituent groups. The alcohol-soluble polymers and copolymers may be used for fabricating organic/inorganic hybrid composites with metal alkoxides M(OZ).sub.v, wherein M is Si, Ti, Al or the like and Z is a lower alkyl group. These polymers and copolymers can also be used to coat materials or substrates which are susceptible to attack by highly corrosive acids.

Abstract: A method for producing a polylactic acid of the present invention includes the steps of (a) polymerizing a lactide used as a main starting material in a molten state to give a polylactic acid; and (b) further polymerizing the polylactic acid obtained in step (a) in a solid phase by heating at a temperature lower than a melting point of a final polymer product.

Abstract: A non-volatile compound useful as a solvent and a method of manufacturing the compound. The compound is formed from heating a combination of a lactide and a drying oil which has conjugated double bonds. The compound is particularly useful as a resin solvent for use with coatings, paints and printing inks. In addition, it can be used as a compatibilizing agent.

Abstract: A block copolymer for use in the fabrication of bioabsorbable articles such as monofilament surgical sutures is prepared by copolymerizing one or more hard phase forming monomers and 1,4-dioxan-2-one, and then polymerizing one or more hard phase forming monomers with the dioxanone-containing copolymer.

Abstract: "Living" polymerization methods are described wherein a bimetallic lanthanide complex initiator is reacted with a monomer. Using these methods, link-functionalized polymers can be formed that are capable of being modified after polymerization with various reactants, or to be biodegraded through oxidation or reduction or cleavage. The bimetallic lanthanide complex initiator can be used to polymerize methyl methacrylate in a living fashion. A two-step method of forming a triblock polymer using the bimetallic lanthanide complex initiator is also disclosed.

Abstract: The present invention provides a process for the continuous production of a biodegradable polyester polymer with an excellent quality useful in the field of medicine, coating material and packaging material by eliminating difficulty in uniform agitation and heat removal caused by the rise in the viscosity of reactants in the production of a high molecular biodegradable polyester polymer by ring-opening polymerization.

Abstract: A method for purifying a material containing a bioabsorbable polymer involves contacting the polymer with an extractant under supercritical conditions of temperature and pressure to extract residual impurities from the polymer and thereafter recovering the purified polymer. The method sharply reduces residual monomer levels in bioabsorbable polymers without altering polymer viscosity or melting point.

Abstract: The poly-.epsilon.-caprolactones are manufactured by continuous polymerization of .epsilon.-caprolactone as a melt in an extruder (reactive extrusion) with the involvement of a polymerization initiator chosen from aluminum alkoxides. The appropriate adjustment of the extruder feed rates of .epsilon.-caprolactone and of aluminum alkoxide allows the customized manufacture of poly-.epsilon.-caprolactones which have high and preestablished weight-average molecular masses.Poly-.epsilon.-caprolactones obtainabled by the process are characterized by weight-average molecular masses (M.sub.w) equal to at least approximately 95,000 g/mol and M.sub.w /M.sub.n ratios of at least approximately 2.

Abstract: Medical devices or components for medical devices formed from bioabsorbable elastomers comprising a random copolymer are disclosed. The random copolymer is a copolymer of from about 30 to about 70 weight percent of: a) .epsilon.-caprolactone, trimethylene carbonate, an ether lactone, or a mixture of these, and b) the balance being substantially glycolide, para-dioxanone, or a mixture of these. The random copolymers surprisingly exhibit elastomeric properties, and the copolymers are bioabsorbable. The combination of physical and biological properties of these elastomeric copolymers are particularly well-suited for numerous medical and surgical applications.

Abstract: The invention relates to the use of copolymers of racemic lactide and .epsilon.-caprolactone, .delta.-valerolactone, gamma-decalactone or .beta.-hydroxybutyric acid, prepared by the reaction of the monomers in the molar ratio of lactide to reaction partner of approximately 95-70 to 5-30, with the addition of metal carboxylates, known per se, as initiators at temperatures of approximately 150.degree. C. over a period of time of approximately 16 to 18 hours, for the topical treatment of human or animal skin.

Abstract: A biodegradable optically active copolymer is disclosed, which is represented by the general formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each represents a hydrogen atom or a methyl group; m and n each represents a natural number wherein the sum thereof gives 10 to 5,000; and C* represents an asymmetric carbon atom, and a process for producing the copolymer by ring-opening copolymerization of optically active .beta.-butyrolactone with a cyclic carbonate in the presence of catalyst. The biodegradable optically active copolymer of the present invention provides excellent biodegradability (enzyme degradability) and hydrolyzability.

Abstract: A lactide polymer composition combining compositional and purity limitations and catalyst optimization or addition of stabilizing agents resulting in a melt-stable polymer is disclosed. The melt-stable lactide polymer comprises a plurality of polylactide polymer chains, residual lactide in concentration of less than 2 percent and water in concentration of less than 1000 parts-per-million. A stabilizing agent in an amount sufficient to reduce depolymerization of the lactide polymer during melt-processing or alternatively, control of catalyst level at a molar ratio of monomer to catalyst greater than 3000:1 is also included in the melt-stable composition. A process for manufacture of a melt-stable lactide polymer composition includes polymerizing a lactide mixture and adding stabilizing agents sufficient to reduce depolymerization of the polylactide during melt-processing, followed by devolatilizing the polylactide to remove monomer and water.

Abstract: A preparation process of polyhydroxycarboxylic acid having an inherent viscosity of 0.3 dl/g or more by dehydrating polycondensation of lactic acid containing hydroxycarboxylic acid in an organic solvent in the presence or absence of a catalyst, comprising using a hydroxycarboxylic acid raw material which comprises one or more impurities selected from the group consisting of methanol, ethanol, acetic acid, pyruvic acid, fumaric acid, methyl lactate, ethyl lactate and butyl lactate in a total amount of 0.3% by mole or less for the amount of said hydroxycarboxylic acid raw material.

Abstract: High molecular weight, biodegradable polymers of substituted-poly(.beta.-propioesters), wherein the repeat unit sequences have a predominantly syndiotactic arrangement and a method of forming such polymers are disclosed. The method includes exposing a substituted-.beta.-propiolactone to a tin-based organometallic catalyst for a sufficient combination of time and temperature to form the predominantly syndiotactic substituted-poly(.beta.-propioester).

Abstract: A process for preparing polyhydroxycarboxylic acid by conducting dehydration polycondensation of hydroxycarboxylic acids in the presence or absence of a catalyst and in the presence or absence of an organic solvent, comprising using a vertical high viscosity reactor during all or a portion of the dehydration polycondensation steps and conducting hot polycondensation while separating and removing low boiling components. The process can provide high molecular weight polyhydroxycarboxylic acid with ease and cheaply in industry.

Abstract: The invention relates to resorbable homopolymers and copolymers which are substantially free from polymerization catalysts and processes for preparing them.

Abstract: A process for producing poly(3-hydroxybutyric acid) comprising ring-opening polymerization of .beta.-butyrolactone is disclosed, wherein the ring-opening polymerization is carried out in the presence of at least one tin compound selected from the group consisting of a distannoxane derivative (e.g., 1-chloro-3-ethoxy-1,1,3,3-tetrabutyldistannoxane), a tin carboxylate compound (e.g., tin dioctanoate), and a di-lower alkyltin oxide (e.g., dibutyltin oxide). Poly(3-hydroxybutyric acid) can be produced in high yield at low cost through simple production steps. The resulting polymer has an increased molecular weight to a degree not heretofore attained.

Abstract: Bales of unvulcanized rubber, or compounding ingredients for unvulcanized rubber are packaged in film or bags made from an ethylene .alpha.-olefin copolymer having a Vicat softening point below 90.degree. C. end a melting point below 100.degree. C., and optionally a second ethylene copolymer is added to improve processability of the first ethylene copolymer. The second ethylene copolymer will contain more long-chain branches than the first ethylene copolymer. Such films may be included in a rubber compounding operation.

Abstract: A catalyst: mixture for ring-opening polymerization of heterocyclic monomers and polymers includes a catalyst composed of a cobalt carbonyl complex; and a cocatalyst composed of at least one Si-H-containing compound. A curable composition, which may be a two-part kit, is also disclosed and includes the catalyst; the cocatalyst; and at least one polymerizable compound which is a monomer or polymer containing a heterocyclic ring. A method of producing a polymeric product by ring-opening polymerization of heterocyclic monomers and polymers is also disclosed which includes the steps of preparing a mixture including a catalyst composed of a cobalt carbonyl complex, a cocatalyst composed of at least one Si-H-containing compound, and at least one polymerizable compound which is a monomer or polymer containing a heterocyclic ring; and reacting the mixture, preferably at about room temperature, to promote ring-opening polymerization of the at least one polymerizable compound to produce the polymeric product.

Abstract: In the preparation of polyester by conducting ring-opening polymerization of a cyclic ester compound in the presence of a hydroxyl compound as a molecular weight regulator in the reaction system, the molecular weight of polyester can be accurately controlled in the desired range by previously estimating the amount of free carboxylic acid contained in the cyclic ester compound and controlling the amount of the hydroxyl compound on the basis of the estimated amount.

Abstract: A non-volatile compound useful as a solvent and a method of manufacturing the compound. The compound is formed from heating a combination of a lactide and a drying oil which has conjugated double bonds. The compound is particularly useful as a resin solvent for use with coatings, paints and printing inks. In addition, it can be used as a compatibilizing agent.

Abstract: Polymers more suitable for use in organ transplantation are formed by coupling biologically active moieties to the free amino groups of polymers formed by incorporation of .alpha. amino acids into polymers formed of alpha hydroxy acids such as lactic acids. In the preferred embodiment, the peptides are coupled to the free amino groups.

Abstract: A purification process of a polyhydroxycarboxylic acid for efficiently removing a catalyst with a simple method from solid polyhydroxycarboxylic acid by bringing the solid polyhydroxycarboxylic acid which is obtained by a catalytic reaction and has an inherent viscosity of 0.1.about.5.0 dl/g into contact with an acid substance in the presence of a hydrophilic organic solvent. Also disclosed is a polyhydroxycarboxylic acid prepared by direct dehydration polymerization having an extremely reduced content of residual catalyst.