Disclosed is a continuous process and device for making polybutylene terephthalate (PBT) resin, particularly high molecular weight PBT resin. Also disclosed are a device for conducting the process, and a monitoring process for determining the carboxylic acid end group concentration of the resulting PBT.

Disclosed are compositions comprising polyesters containing a chain of residue of: diols and diesters along the chain, wherein at least a portion of the diesters are 1, 1-diester-1-alkenes, and the chains have alkene groups incorporated into the chains; the composition comprising one or more of the following: i ether groups derived from alcohols, diols, polyols, or a combination thereof obtained via Michael addition to the alkene groups and a residue of the alkene groups remaining after Michael addition; ii the formed polyesters contain one percent or less of residual 1, 1-diester-1-alkene which are unreacted; iii one or more free radical inhibitors; and iv a stabilizer comprising one or more of: oxo acids phosphorous or esters thereof, aluminum sulfate, stannous pyrophosphate, stannous sulfate, aluminum dihydrogenphosphate or decomposition products thereof. The stabilizer is present in an amount sufficient to enhance stability of the polyester without lowering reactivity of the polyester.

The present invention relates to a process for polymerising lactide into polylactic acid. The present invention also relates to reactor configuration for polymerising lactide into polylactic acid.

The present invention relates to a method for reducing the transition time and/or the polymer waste being out of the specification during the change from a first polymer grade to a second polymer grade in a continuous polymerization process conducted in a polymerization plant, wherein the polymerization plant comprises at least one back-mixing reactor, at least one monomer and at least one processing agent selected from the group consisting of catalysts, co-catalysts, polymerization initiators, comonomers, chain-transfer agents, branching agents, solvents and arbitrary combinations of two or more of the aforementioned agents are added before and/or during the polymerization process into the at least one back-mixing reactor, wherein the concentration of one or more of the at least one added processing agent in the feed introduced into the at least one back-mixing reactor is varied as a function of time from a first value associated with the first polymer grade to a final value associated with the second polymer grade, —the first polymer grade and the second polymer grade are one or more parameters related to the molecular weight of the polymer to be produced and/or one or more parameters related to the composition of the polymer to be produced and/or one or more parameters related to the structure of the polymer to be produced and/or one or more parameters related to the amount of the polymer to be produced, wherein during the variation of the concentration of the at least one added processing agent from the first value to the final value one or more intermediate values are adjusted, wherein at least one, preferably the majority and more preferably all of the one or more intermediate values are closer to the final value than to the first value, wherein the absolute difference between the at least one, preferably each of the majority and more preferably each of all of the one or more intermediate values from the first value is greater than the absolute difference between the final and the first value, wherein the one or more intermediate values are maintained for a time which is calculated on the basis of only residence time in the at least one back-mixing reactor and steady-state correlations between input and output of the reactor and/or of the polymerization plant, and wherein the method is performed without performing dynamic modelling.

There is described a process for preparing a biodegradable polyester from an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid and a diol where in a first reaction step the aromatic acid is esterified with the diol, and in a second reaction step the aliphatic acid is added to the reaction mixture. Furthermore, there is described an apparatus for carrying out this process.

A method for preparing a biogenic guanidine complex, the method including: mixing dimethyl sulfoxide (DMSO) with water in a volume ratio thereof of 1:1 to yield a solvent DMSO-H.sub.2O; adding organic guanidine (G) and a compound MX.sub.2 in a molar ratio G/MX.sub.2=1:1 or 2:1 to the solvent DMSO-H.sub.2O, where the organic guanidine (G) is selected from arginine (Arg), guanidinoacetic acid (Gaa), creatine (Cra), creatinine (Cran), guanine (Gua), and agmatine (Agm); M represents Fe.sup.2+, Mg.sup.2+, or Zn.sup.2+; and X represents Cl.sup.−, CH.sub.3COO.sup.−, or CH.sub.3CH(OH)COO.sup.−; stirring the solvent DMSO-H.sub.2O containing the organic guanidine and the compound MX.sub.2; recycling the solvent DMSO-H.sub.2O through vacuum distillation and obtaining a solid; transferring the solid to a Buchner funnel, and washing the solid with deionized water and ethanol consecutively; and removing the deionized water and ethanol through vacuum filtration, and drying the solid.

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.

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.

The invention relates to an integrated process for producing a polyglycolic acid product, including polymerization, modification and molding. The resulting polyglycolic acid product may maintain the physical and chemical properties of polyglycolic acid to the greatest extent, including yellowness index (YI), weight-average molecular weight, strength and mean square radius of rotation. Also provided are the polyglycolic acid product and apparatus for carrying out the integrated process.

The present invention relates to the field of high polymer material manufacturing, and discloses an air-isolated continuous feeding system for synthesizing polylactic acid from lactide and a feeding method thereof. The continuous feeding system comprises a raw material bag/box and a raw material collector for collecting and outputting lactide, the raw material bag/box is connected with a shielding gas input pipeline, a discharge pipe is movably inserted into the raw material bag/box, a cyclone separator is connected downstream of the discharge pipe, and a solid substance outlet of the cyclone separator is connected with the raw material collector. According to the invention, deterioration of the lactide raw material incurred by moisture absorption and oxidation is avoided, and the reaction conversion ratio and final product purity are improved. The continuous feeding system is easy to operate, can save manpower and material resources, and is applicable to industrial application.