46 results about "Intrinsic viscosity" patented technology

This invention discloses a method for preparing poly(glycolic acid-caprolactone) copolymers, belonging to the field of polymer synthesis technology. The method includes: prepolymerizing ε-caprolactone with a catalyst and initiator at 40–60°C below the melting point of glycolide under an inert atmosphere; adding glycolide and heating to 160–220°C for the main polymerization reaction; after the reaction, dissolving, precipitating, washing, and drying to obtain the poly(glycolic acid-caprolactone) copolymer. This invention utilizes the physical difference in melting points between glycolide and ε-caprolactone, preferentially prepolymerizing ε-caprolactone at a temperature below the melting point of glycolide, resulting in a higher conversion rate of ε-caprolactone than glycolide in the initial stage of the main polymerization, effectively controlling the copolymerization reaction pathway. Using this method, copolymers with a weight-average molecular weight of not less than 100,000 Da and an intrinsic viscosity of 1.8–3.5 dL / g can be obtained within a wide range of glycolide molar content from 15% to 85%, and the degradation behavior is stable and controllable. This method is simple and requires no special equipment or chain extender, making it suitable for the large-scale preparation of medical materials such as absorbable sutures and tissue repair scaffolds.

The present application relates to the technical field of detection, and particularly relates to a method for measuring intrinsic viscosity of rubber by using chlorobenzene solution, comprising the following steps: obtaining initial mass of insoluble polymer sample; filtering solution of the sample to obtain mass of insoluble substance intercepted by filter medium; cleaning container of the sample of the solution and collecting cleaning liquid to obtain mass of container residue; determining real sol mass based on the mass of the residue, the mass of the insoluble substance and the mass of the container residue; and determining concentration of the solution based on the real sol mass and volume of the solution. The present application effectively solves the technical problem of large error in measuring intrinsic viscosity by using tetrahydrofuran solvent, and simultaneously provides an alternative scheme for evaluating quality of natural rubber.

The present invention aims to solve the above problems and provide a monofilament that has low intrinsic viscosity while possessing high hydrolysis resistance, which was not possible with conventional technology. [Solution] A polyester monofilament comprising a resin composition mainly composed of polyester resin, wherein the resin composition contains 0.01 to 4.00 parts by mass of an amine compound and 0.01 to 4.00 parts by mass of an isocyanate compound per 100 parts by mass of polyester resin.

The application discloses a kind of polyether ketone ketone and preparation method thereof, the application is first added terephthaloyl chloride or isophthaloyl chloride and diphenyl ether, then under the condition of adding catalyst anhydrous aluminium chloride, low-temperature prepolymerization for a certain time, then the remaining diphenyl ether is added to complete the short-chain end-capping reaction.The application reduces the temperature in the early stage of the starting reaction process and adopts the reflux method in the selection of the washing reagent in the later stage, so that the purity and molecular weight of the obtained high molecular polymer polyether ketone ketone are high.The content of aluminum, a catalyst contained in PEKK, is lower, and the intrinsic viscosity (molecular weight) and tensile strength of the tested product are higher.

This invention provides a polyester resin composition derived from chemical recycling that exhibits excellent transparency, low levels of minute foreign matter, and heat resistance, possesses an intrinsic viscosity suitable for film molding, and has excellent electrostatic application properties for film, thereby significantly increasing film yield. [Solution] A polyester resin composition containing chemically recycled polyethylene terephthalate, wherein the following (1) to (5) are within the specified range. (1) Intrinsic viscosity of polyester resin composition, (2) The amount of antimony element contained in the polyester resin composition, (3) The molar ratio of metal elements and phosphorus elements contained in the polyester resin composition, (4) The isophthalic acid content in the chemically recycled polyethylene terephthalate, and (5) Content of coarse foreign matter with an equivalent circular diameter of 1 μm or more in the chemically recycled polyethylene terephthalate.

The present application relates to a kind of water environment degradable copolyester that can be melt spun, fiber and its preparation method and application, belong to degradable polymer material technical field.The copolyester is random aliphatic-aromatic copolyester comprising terephthalic acid propylene glycol ester structural unit and diethylene glycol acid propylene glycol ester structural unit;Wherein, diethylene glycol acid propylene glycol ester structural unit accounts for 23.10~53.02 mol% of total mole amount of diacid structural unit, copolyester randomness is 0.90~1.10, and intrinsic viscosity is not less than 1.0 dL / g.The copolyester can be prepared by esterification and melt polycondensation reaction of terephthalic acid, diethylene glycol acid and 1,3-propylene glycol.By introducing the above two structural units, the copolyester of the present application has high glass transition temperature, good melt spinning stability and water environment degradation performance, and can be used to prepare degradable fiber, non-woven material, packaging film and water environment degradable material.

This invention provides a positive electrode sheet, its preparation method, and an electrochemical device. The positive electrode sheet includes a current collector and an active material layer on at least one surface of the current collector. The active material layer includes a positive electrode active material, a conductive agent, and a binder. The binder includes PVDF. The PVDF has a weight-average molecular weight to intrinsic viscosity cofactor of λ, where λ satisfies: λ = (Mw / 10 6 The formula is: Mw × (IV / 300), 0.7 ≤ λ ≤ 2.1; where Mw is the weight-average molecular weight of the PVDF, in g / mol; and IV is the intrinsic viscosity of the PVDF, in mL / g. The positive electrode sheet of this invention controls the molecular weight and intrinsic viscosity of PVDF to satisfy a specific relationship, which ensures high bonding strength of PVDF while forming a superior three-dimensional network structure in the positive electrode sheet, effectively suppressing positive electrode particle breakage and improving the high-temperature cycle performance of the battery.

The application discloses a kind of polysebacic acid terephthalate, polyester composition and its preparation method and application.The weight average molecular weight of the polysebacic acid terephthalate is 70000~155000, and the intrinsic viscosity is 1.20~1.45 dL / g.The specific weight average molecular weight and intrinsic viscosity of the polysebacic acid terephthalate can significantly improve the deformation resistance and stiffness of the film made of polyester composition in the case of high addition amount in polyester composition.

One aspect is a method for producing a first intermediate product. A feedstock of a first polyester is provided. The feedstock is contacted with a first amount of a first organic liquid compound in a volume section to obtain a first initial mixture. The first polyester is contacted with a further organic compound in a volume section to obtain a further initial mixture. A weight average molar mass of the first polyester is reduced to obtain a first intermediate mixture. The first intermediate mixture comprises a first intermediate product and the further organic compound. The first polyester is transported in a first direction opposite the direction of gravity when the first polyester has an intrinsic viscosity that is larger than or equal to 0.10 dL / g, and in the direction of gravity when the first polyester has an intrinsic viscosity that is less than or equal to 0.09 dL / g.

The application discloses a high-IV PBT resin without solid-phase tackifying, which is prepared by melt polycondensation of terephthalic acid component and 1,4-butanediol component, and is not subjected to solid-phase tackifying (SSP) treatment; the terephthalic acid is regenerated terephthalic acid (r-PTA), and the content of p-toluic acid (p-PTA) is less than or equal to 30 ppm; the content of p-carboxybenzaldehyde (4-CBA) is less than or equal to 10 ppm. By limiting the regenerated r-PTA (p-PTA less than or equal to 30 ppm, 4-CBA less than or equal to 10 ppm) and SSP-free melt polycondensation, the risks of thermal oxidation yellowing and carboxyl end group increase of the SSP process are avoided from the source. The hindering to chain growth is reduced, and the balance between high intrinsic viscosity and low acid value of the resin is ensured without solid-phase tackifying, the product has excellent color and hydrolysis stability, and is widely suitable for optical communication and high-end engineering plastic fields.

This invention discloses a CPVC adhesive, its preparation method, and its application. The CPVC adhesive comprises the following components by weight percentage: 8-12% chlorinated polyvinyl chloride resin, 20-25% first main solvent, 28-35% second main solvent, 25-35% co-solvent, 0.1-0.5% thickener, 5-7% auxiliary resin, 0.02-0.3% stabilizer, and 0.1-0.3% colorant; the first main solvent is cyclohexanone; the second main solvent is tetrahydrofuran; the thickener is styrene-acrylonitrile copolymer; the intrinsic viscosity of the styrene-acrylonitrile copolymer is 8-10 dL / g; and the viscosity of the CPVC adhesive at 25°C is above 1000 cps. The CPVC adhesive provided by this invention effectively improves the problem of decreased compatibility and adhesion caused by the introduction of color powder by adding an appropriate amount of styrene-acrylonitrile copolymer as a thickener. This allows the CPVC adhesive to achieve rich colors while still having excellent adhesion and storage stability.

The application discloses a preparation method of a binary acid and alcohol modified polybutylene succinate copolyester. The preparation method uses binary acid and binary alcohol as modifiers, sequentially passes through a first esterification reaction, a second esterification reaction, a pre-polycondensation reaction and a final polycondensation reaction to obtain the modified polybutylene succinate copolyester. The initial esterification temperature is reduced through a two-stage esterification mode, the problem that 1,4-butanediol is easy to dehydrate to form a cyclic byproduct under high temperature is overcome, the consumption of the raw material 1,4-butanediol is effectively reduced, and the use of a toxic metal compound is avoided through the use of an organic ring-opening catalyst in the polymerization process, so that the problems existing in the prior art are solved. The method is simple in operation, wide in application range, provides a flexible modifier adding mode for the production of modified copolyesters, enriches the product types of the degradable polyester family, and the obtained product is stable in quality, high in intrinsic viscosity and good in quality.

This invention belongs to the field of synthetic fiber technology and relates to a method for reducing the amount of loose fibers in light-sensitive deep black polyester fibers. During the production of light-sensitive deep black polyester fibers using bright polyester and carbon black masterbatch as raw materials, when loose fibers occur, it is determined whether a breakage has occurred. If so, the winding machine is immediately stopped; otherwise, it is stopped after a full wind. After the winding machine stops, the component pressure is increased to 19-20 MPa and maintained for 3-5 minutes before the component pressure is restored. The winding machine is restarted after the component pressure is restored. The carbon black masterbatch contains titanium dioxide. The component pressure is increased by increasing the pump supply while reducing the chamber temperature. The base material of the carbon black masterbatch is low-viscosity polyester with an intrinsic viscosity of 0.58-0.60 dL / g. This invention uses low-viscosity polyester as the base material for the carbon black masterbatch and regulates the component pressure to reduce loose fibers, extend component life, and stabilize production.

This invention provides a wear-resistant polyester nonwoven fabric and its preparation method. The invention employs a two-step gradient nucleation control technology. First, graphene oxide with an oxidation degree of 20-25% and a sheet size of 3-8 µm is added as a primary nucleating agent when the intrinsic viscosity of the polymerization system is 0.15-0.25 dL / g. Second, graphene oxide with an oxidation degree of 35-40% and a sheet size of 0.5-2 µm is added as a secondary nucleating agent when the intrinsic viscosity is 0.3-0.4 dL / g. The addition of the first and second graphene oxides at different times, through their synergistic effect, forms a gradient grain structure, which is beneficial for improving the wear resistance of the polyester nonwoven fabric.

According to an example aspect of the present invention, there is provided a method comprising treating a composition comprising paper-grade pulp with ozone to adjust intrinsic viscosity of the paper-grade pulp to below 550 ml / g The paper grade-pulp comprises at least 10 wt-% of hemicellulose of the dry weight of the paper-grade pulp, and the pH of the composition is at least 5.5 at the beginning of the treatment.

A prepolymer catalyst component for olefin polymerization, characterized in that it comprises: (a) a solid catalyst component comprising Ti, Mg, and a halogen, and a bidentate electron donor compound (BE), wherein the amount of the bidentate electron donor compound is such that the (BE) / Ti molar ratio ranges from 0 to 0.3; and (b) an ethylene (co)polymer, wherein the amount of the ethylene (co)polymer ranges from 0.1 to no more than 30 g per g of the solid catalyst component, and wherein the intrinsic viscosity measured in tetrahydronaphthalene at 135 °C is at least 3.0 dL / g; the prepolymer catalyst component also exhibits a porosity of 0.1 to 1 cm² as measured by the mercury method. 3 Within the range of / g, the prepolymerized catalyst exhibits high morphological stability and produces a small amount of fine particles.

This invention belongs to the field of polymer materials, specifically relating to a method for preparing polycarbonate using a non-phosgene melt transesterification method, and the resulting polycarbonate. The invention involves mixing bisphenol A and diphenyl carbonate at an optimized molar ratio, followed by a transesterification reaction to obtain oligomers. The oligomers are then subjected to a pre-condensation reaction under optimized temperature and pressure, with the residence time controlled to achieve an ideal intrinsic viscosity window. The prepolymer is then subjected to a first and final condensation reaction sequentially to obtain polycarbonate. This invention, through the coordinated control of temperature, pressure, and feed molar ratio during the pre-condensation stage, stabilizes the intrinsic viscosity of the prepolymer within the ideal window, laying a high-quality feed foundation for subsequent condensation polymerization. This significantly improves the impact strength and performance stability of the product, while effectively reducing diphenyl carbonate loss and controlling the end-hydroxyl content of the product. This provides a complete method for the preparation of high-performance polycarbonate.

This invention discloses a method for catalytically depolymerizing waste poly(p-dioxanone) to recover monomers, belonging to the field of heterocyclic compound technology. The method includes: mixing an oxide and / or hydroxide of an alkali metal or alkaline earth metal with a polyol, stirring and reacting under atmospheric pressure (100-180℃) or reduced pressure (10-120℃) while removing moisture to obtain a catalyst; mixing the obtained catalyst with waste poly(p-dioxanone), and carrying out a depolymerization reaction under an absolute pressure of 0.1-30 kPa and a temperature of 120-180℃, the generated poly(p-dioxanone) monomer being continuously distilled off by reduced pressure distillation and collected by condensation; the collected crude distillate being purified by reduced pressure distillation to obtain polymerization-grade poly(p-dioxanone) monomer. Experiments show that the purified monomer yield can reach 99%, with a purity of not less than 99.5%, and the recovered monomer can be used for ring-opening polymerization to synthesize poly(p-dioxanone) with an intrinsic viscosity ≥1.8 dL / g. This invention features a low-cost catalyst raw material, mild depolymerization conditions, good reaction system fluidity, recyclable catalyst, low purification loss, and is easy to implement industrially.

To obtain a recycled polyester film with high edge tear resistance. [Solution] A recycled polyester film having an intrinsic viscosity IV of 0.55 dl / g or more and 0.65 dl / g or less, a rheometer viscosity ηH of the film at 280°C and a shear rate of 31.4 rad / s of 100 Pa·s or more and 250 Pa·s or less, and a Tmeta of the film observed by differential scanning calorimetry (DSC) of 195°C or more and 235°C or less.

Ethylene-based polymers, articles made therefrom, and processes for making same. The ethylene-based polymer can include polymer units derived from ethylene and polymer units derived from one or more C3 to C18 α-olefin monomers. The ethylene-based polymer can have a melt index (I2) of 0.1 g / 10 min to 10 g / 10 min, a density of 0.890 g / cm3 to 0.910 g / cm3, a CDBI of 60% to 80%, a number average molecular weight of 25,000 g / mol to 53,000 g / mol, and an intrinsic viscosity of 1.3 dL / g to 1.9 dL / g. In some embodiments, the ethylene-based polymer can also have one or more of the following: a composition distribution breadth T75-T25 value, as measured by TREF, of 16.5° C. to 21° C., a complex viscosity measured at a shear rate of 10 rad / s of 5,700 Pa·s to 8,700 Pa·s, and a complex viscosity measured at a shear rate of 0.1 rad / s of 11,100 Pa·s to 14,100 Pa·s.

This application provides a method for preparing colored automotive interior fabric, belonging to the field of high-performance fabric technology. Using PET chips, pigments, dispersants, and auxiliaries as raw materials, PET masterbatch is prepared. The PET chips have an intrinsic viscosity of 0.60~0.75 dL / g, the pigment has a particle size ≤100nm, a temperature resistance ≥280℃, and a mass percentage of 5~60%; the dispersant has a mass percentage of 3~8%; the auxiliaries have a mass percentage of 0.1~8%; and the remainder is PET chips. Using PET and COPET as raw materials, the PET masterbatch is added, and composite spinning is performed to form microfiber colored spun island yarn. The microfiber colored spun island yarn has a fineness of 2~5 dtex. The microfiber colored spun island yarn is woven to obtain a grey fabric, which is then opened, brushed, and fixed to obtain the automotive interior fabric. The automotive interior fabric prepared by this method has advantages such as low monofilament fineness, a feel close to genuine leather, color fastness of not less than grade 4, good physical properties, and low dyeing wastewater discharge.

This invention belongs to the field of copolyester preparation technology and discloses a method for preparing PETG copolyester. The raw materials terephthalic acid, ethylene glycol, and CHDM undergo esterification and polycondensation reactions in an esterification catalyst and a polycondensation catalyst system to obtain the polymer PETG copolyester; wherein the molar ratio of terephthalic acid, ethylene glycol, and CHDM is 1–1.05:0.9–1.15:0.2–0.52. The preparation method of this invention can produce high-viscosity, high-transmittance, and low-color-value PETG copolyester products with intrinsic viscosity above 0.78 dl / g, light transmittance above 93.00%, L value above 70, and b value below -0.5.

This invention discloses a PVC adhesive, its preparation method, and its application. The PVC adhesive comprises the following components by weight percentage: 8-12% polyvinyl chloride resin, 25-30% first main solvent, 20-30% second main solvent, 25-35% co-solvent, 0.1-0.5% thickener, 5-7% auxiliary resin, 0.02-0.3% stabilizer, and 0.1-0.3% colorant; the first main solvent is cyclohexanone; the second main solvent is tetrahydrofuran; the thickener is styrene-acrylonitrile copolymer; the intrinsic viscosity of the styrene-acrylonitrile copolymer is 8-10 dL / g; and the viscosity of the PVC adhesive at 25°C is above 500 cps. The PVC adhesive provided by this invention, by adding an appropriate amount of styrene-acrylonitrile copolymer as a thickener, effectively improves the problem of decreased compatibility and adhesive performance caused by the introduction of colorant, enabling the prepared PVC adhesive to achieve rich colors while still possessing excellent adhesive performance and storage stability.

This invention discloses a high-speed spun polybutylene terephthalate (PBT) resin, which is formed by the condensation polymerization of recycled terephthalic acid (r-PTA) and 1,4-butanediol (BDO). The terephthalic acid is recycled terephthalic acid (r-PTA), with a p-methylbenzoic acid (p-TA) content ≤30ppm and a p-carboxybenzaldehyde (4-CBA) content ≤10ppm. The intrinsic viscosity (IV) of the resin is 0.80 to 1.15 dL / g; the terminal carboxyl group content (AV) is ≤20 mol / t; and the molecular weight distribution index (PDI=Mw / Mn) is 1.8 to 2.2. The PBT resin of this invention has the characteristics of narrow molecular weight distribution, high melting point, and low acid value, and supports high-speed spinning at 2000-2200 m / min. The prepared DTY (dilatation textured yarn) fibers have high crimp shrinkage (good elasticity) and good hydrolytic stability, making them widely applicable in the textile fiber field, especially suitable for the production of high-end high-elastic fabrics.

The application discloses a kind of scratch-resistant weather-resistant PBT composite material and preparation method thereof, belong to the field of high polymer materials.The composite material includes the following weight parts raw materials: PBT resin 70~90 parts;Titanium dioxide 10~30 parts;Coupling agent 2~5 parts;Zirconium phosphate 5-10 parts;The PBT resin specific viscosity 0.65~0.95dL / g;The total weight of PBT resin and titanium dioxide is 100 parts.Summarizes relative to prior art, the PBT composite material of the application has excellent scratch resistance, weather resistance, good quality, and has very high application potential in the bathroom industry.

The application provides a polyoxalate and a preparation method thereof. The polyoxalate comprises structural units derived from oxalic acid and structural units derived from dihydric alcohol, the weight average molecular weight of the polyoxalate is 120,000-1,000,000 g / mol, the color of the polyoxalate is a color L value of 80-86, an a value of -4 to -2.0, and a b value of 1.5-10 according to the method B in the test method of color in GB / T14190-2008. The polyoxalate according to the application has the advantages of high molecular weight, large intrinsic viscosity, good color and the like.

The application discloses a kind of high elongation p-aramid fiber and preparation method thereof, it is related to high-performance fiber material technical field, with p-phenylenediamine solution and p-phthaloyl chloride is continuously condensed in two steps in low temperature environment, obtains the poly-p-phenyleneterephthalamide polymer with intrinsic viscosity of 6.5dL / g~7.0dL / g;Polymer is dissolved in concentrated sulfuric acid with concentration of 97%~103%, is stirred and dissolved at 80~90 DEG C, obtains the liquid crystal state spinning dope with concentration of 18%~21%;Spinning dope is defoamed by vacuum, filtration, metering, and is extruded through spinneret, enters 20~30 DEG C coagulation bath through 3mm~20mm air layer, forms nascent fiber;Nascent fiber is sequentially neutralized, washed, dried, oiled, and is wound into shape with draft ratio of 2m / min~10m / min, and high elongation p-aramid fiber is prepared.The application is compared with prior art and has the advantages that molecular chain hydrogen bond density is regulated, condensed state structure is optimized, and process is accurately controlled.

The present invention provides a masterbatch that, when diluted with a polyester resin, yields a resin composition with good processability and moldability, as well as good transparency and low yellowness. [Solution] A masterbatch containing amorphous PET (A) and a chain extender (B) having a weight-average epoxy functional group count of 3 to 65 and a weight-average molecular weight of 2000 to 30000, wherein the content of the chain extender (B) in the masterbatch is 5 to 30% by mass, and the intrinsic viscosity of the resin composition containing the masterbatch and a polyester resin (C) is 0.7 dL / g to 1.3 dL / g, and is for use in food containers, non-food containers, or sheets.