38results about How to "Short polycondensation time" patented technology

The invention discloses a biodegradable linear random copolyester, its preparation method and uses, wherein the copolyester has a structural unit of (1), wherein m is an integer of 2-10, n is an integer of 0-8, p is an integer of 2-10, m, n, p are identical or different, x is an integer of 1-10, y is an integer of 1-10, the average molecular weight Mw of the copolyester is 100,000-600,000g/mol, its molecular weight distribution is 1.2-3, which is measured through GPC method. The copolyester can be widely applied into section bar, film, fabric and coating.

The invention discloses a method for synthesizing a biodegradable aliphatic-aromatic copolyester. The method comprises the following steps: performing continuous esterification on aromatic dicarboxylic acid and aliphatic dicarboxylic acid, adding epoxidized soybean oil, performing continuous prepolycondensation, grafting an epoxy ester into a polyterephthalic acid-adipic acid butanediol PBAT molecular chain in the prepolycondensation process, and performing continuous polycondensation under a condition of a higher temperature, so as to enable the molecular weight and the specific viscosity totarget values. By adopting the method for synthesizing the biodegradable aliphatic-aromatic copolyester, the polyester can easily meet target specific viscosities and molecular weights, the polycondensation time of a high-temperature high-viscosity material can be shortened, side reactions can be reduced, the carboxyl value of a product end can be reduced, and the problem of resin yellowing can besolved. By adopting the method for synthesizing the biodegradable aliphatic-aromatic copolyester, chain extension is implemented without a micromolecule chain extender, so that the problem that a residual chain extender is migrated to a food from a plastic can be solved.

The present invention discloses a foamable PET resin, a preparation method and uses thereof. The preparation method comprises: (1) uniformly mixing raw material components, wherein the raw material components comprise 985-995 parts of physically recycled PET bottle flakes, 1-9 parts of a chain extender, 1-3 parts of an antioxidant, and 1-3 parts of a thermal stabilizer, and a three-functional-group chain extension monomer and a multi-functional-group chain extension monomer having a functional group number of 4-6 are compounded according to a mass ratio of 1:3-5:1 to prepare the chain extender; (2) carrying out melt extrusion granulation; and (3) carrying out solid phase condensation polymerization on the obtained material for 1-5 h at a temperature of 210-230 DEG C under a vacuum degree of 5-100 Pa so as to obtain the foamable PET resin. According to the present invention, the foamed PET resin has characteristics of high molecular weight, wide molecular weight distribution, high melt strength, physically recycled PET degrading use changing, low raw material cost, and simple preparation process; and with the combination of the chain extender, the reaction extrusion and the solid phase condensation polymerization are combined, such that the reaction period is shortened, and the industrial production is easily achieved.

The invention belongs to the technical field of polyester preparation, and discloses a modified PET copolyester with high viscosity and a low terminal carboxyl group and a preparation method and application thereof. The copolyester contains the following ingredients in parts by weight: 100 parts of low-viscosity PET copolyester, 0.8-2.0 parts of oxazoline compound and 0.6-2.0 parts of a hydroxyl chain extender. The method prepares the high-viscosity modified PET copolyester by adding the oxazoline compound and the hydroxyl chain extender. The oxazoline compound is added to react with the terminal carboxyl group in resin, the terminal carboxyl group content of resin is reduced, therefore, the hot water resisting performance of resin is increased. The hydroxyl chain extender is added, the molecular weight of resin is increased, and the balance between a physical performance and a processing performance is achieved. The viscosity and the melt strength of the modified PET copolyester are increased, the content of terminal carboxyl group is reduced, and the hot water resisting performance is greatly increased. Moreover, the production method shortens the polycondensation time and the production cycle, effectively reduces the thermal degradation reaction, and also increases the output of equipment.

The invention belongs to the technical field of polyesters and discloses a modified aliphatic-aromatic copolyester having high viscosity and low carboxyl end group content and its preparation method and use. The modified aliphatic-aromatic copolyester comprises, by weight, 100 parts of a low-viscosity aliphatic-aromatic copolyester, 0.5-3 parts of an oxazoline compound and 0.4-2.5 parts of a hydroxyl chain extender. Through use of the oxazoline compound and the hydroxyl chain extender, the modified aliphatic-aromatic copolyester is prepared. The used oxazoline compound and the carboxyl end group in the resin undergo a reaction so that resin carboxyl end group content is reduced and resin hot-water resistance is improved. Through use of the hydroxyl chain extender, resin molecular weight is improved and the balance of physical properties and processing properties is realized. Viscosity and the melt-strength of the modified aliphatic-aromatic copolyester are improved, carboxyl end group content is reduced and hot-water resistance is improved. The preparation method has a short production period, reduces polycondensation time and effectively reduces thermal degradation reactions.

The present invention is preparation process of fiber-forming biodegradable fatty copolyester. In the single kettle operation, the composite catalyst system comprising the main catalyst of metal compound of Ti, Sb or Zn and the co-catalyst of metal ion salt of Ca, Mg, Na or K, or phosphoric acid derivative, and the monomer material are added into the polymerization kettle simultaneously. After esterification or ester exchange reaction for 1-2 hr, the materials are vacuum polycondensated. The preparation process of the present invention has simple operation, fast polymerization reaction speed, raised polymer molecular weight, less side products and improved polymer color.

The invention relates to a preparing method for producing flame-retardant polyester fibers through recycled polyester bottle flakes. The preparing method includes the step of preparing flame-retardant polyester parent materials, wherein 28 mass parts to 32 mass parts of ethanediol, 68 mass parts to 72 mass parts of purified terephthalic acid, 80 ppm to 300 ppm of antimony-based catalysts and 100 ppm to 500 ppm of stabilizers are added into a pulping kettle to be stirred and prepared into pulp I; the pulp I is guided into an esterification kettle and heated to 245 DEG C to 260 DEG C to be esterified, 15,000 ppm to 30,000 ppm of flame retardant assistants, 0 mass part to 1.2 mass parts of flatting agents and 200 ppm to 500 ppm of antioxidants are added for continuously carrying out the esterification reaction, and flame-retardant bis(2-hydroxyethyl)terephthalate II is prepared; the flame-retardant bis(2-hydroxyethyl)terephthalate II is guided into a condensation polymerization kettle to be heated, the vacuum degree is controlled to be 1,200 Pa to 1,800 Pa, and pre-condensation polymerization is carried out; then the vacuum degree is adjusted to be lower than 80 Pa, and heating is carried out for condensation polymerization till the condensation polymerization reaction is finished; the flame-retardant polyester parent materials III are obtained through band casting, cooling and pellet cutting, and the content A ppm of P of the flame-retardant polyester parent materials III is detected.

The invention discloses a method for preparing a linear polyester resin. The method is a polymerization process of synthesizing the linear polyester resin from dibasic acid and dihydric alcohol in the presence of a special catalyst. The production process is as follows: adding adipic acid, ethylene glycol and 1,4-butanediol to a reaction still according to the matching ratio to enable the mixed materials to be subjected to an esterification reaction at a temperature of below 140 DEG C; then, increasing the temperate and reacting for several hours at the presence of a new catalyst; removing the water and excess dihydric alcohol generated during the reaction and measuring the acid value and viscosity of the produced material; cooling the material to an indoor temperature when the fact that the reaction is ended is judged and adding a solvent for dilution; packaging the dilute material to obtain the finished product.

The invention discloses a polycondensation catalyst for polyester synthesis and a preparation method and application thereof. The preparation method comprises the following steps: carrying out homogeneous blending on a Ti<3>C<2>T<x>MXene material and a benzoxazine monomer to obtain a blend, then carrying out heating for curing treatment to obtain a Ti<3>C<2>T<x>MXene/benzoxazine resin composite material, and finally, irradiating the Ti<3>C<2>T<x>MXene/benzoxazine resin composite material with laser to prepare the polycondensation catalyst for polyester synthesis. The prepared polycondensation catalyst for polyester synthesis has high catalytic activity, and polyester with higher molecular weight can be obtained through polycondensation polymerization within shorter time, so the tensile modulus, tensile strength and other mechanical properties of polyester are improved. In addition, side reactions such as raw material diacid decarboxylation and thermal degradation of polyester can be inhibited by shorter polymerization time, so the obtained polyester has better hue. Moreover, LIG in the polyester can increase the crystallization rate of the polyester and enhance the conductivity of the polyester, so a polyester product is endowed with antistatic performance.

The invention relates to an application of 5-amido-6-hydroxy-2-(p-carboxyl phenyl) benzoxazole carboxyl ammonium salt (ABAS) in preparing poly(p-phenylene benzobisoxazole) (PBO) resin. The prepared ABAS monomer has the advantages of containing no polymerization inhibitors (such as DMF, DMAc and DMSO and other solvent residues) which affect the condensation polymerization of the ABA for preparing the PBO, good oxidation resistance and thermal stability, and realizing polycondensation with equivalent proportion to further enhance the PBO molecular weight and reduce the polymerization time, and the like, and the application can be developed into a new technology for implementing the PBO resin and the fiber industrialization at low cost.

The invention provides a method for preparing polycarbonate through catalysis of a binuclear ionic liquid, which comprises the following steps: by using a dihydroxy compound and a diester carbonate asraw materials, adding the raw materials into a reactor according to the molar ratio of (1: 0.9)-(1: 8), and synthesizing polycarbonate by using binuclear imidazolyl ionic liquid as a catalyst througha melt transesterification method under the protection of inert gas. Compared with literature reports, the weight-average molecular weight of the synthesized polycarbonate reaches 5 * 10 < 4 >-16 * 10 < 4 > g/mol, the transesterification time is shortened by 25%-50%, and the polycondensation time is shortened by 20%-40% by regulating the length of an alkyl chain between double imidazole rings andchanging the structure of anions under the synergistic catalytic action of anions and cations.

The invention discloses a catalyst system for synthesizing aliphatic-aromatic copolyester and application of the catalyst system. The catalyst system is composed of a titanium composition and a metal composition. The titanium composition is prepared by dissolving a titanium compound, hydroxycarboxylic acid and phosphate in 1, 4-butanediol, heating to react, removing small molecules and cooling to room temperature, and the metal composition is prepared by dissolving titanate, tetraethoxysilane and one metal compound selected from aluminum and zinc compounds in absolute ethyl alcohol, and conducting co-hydrolysis reaction, filtration and vacuum drying, wherein the molar ratio of the titanium composition to the metal composition is 1: 1-1: 10. The method is suitable for preparing copolyester with the aliphatic-aromatic group mole number ratio of 70/30-30/70, and the molecular weight of the copolyester is 5000-150000 g/mol. The catalyst system is environmentally friendly, side reactions are reduced, and the hue of an aliphatic-aromatic copolyester product is improved.

The invention provides a novel polyether ester elastomer and a preparation method thereof, wherein the polyether ester elastomer is prepared by carrying out a mixing reaction on the following components by mass: 100 parts of polyester polyol, 25-100 parts of polyether polyol, and 5-55 parts of isocyanate, preferably, 50-100 parts of polyether polyol, preferably 8-28 parts of isocyanate. Accordingto the present invention, the polyether ester elastomer can be prepared through the reaction within a relatively short time, and has good resilience performance.