20 results about "Isothermal crystallization" patented technology

The invention relates to a large-size glass product with a natural ice crystal imitating effect and an industrial casting method of the large-size glass product. The product is a lead-free glass casting with the weight larger than or equal to 100 kg, dendritic crystal-shaped or snowflake-shaped devitrified phases which are formed by growing calcium fluoride as crystal nucleuses and are distributed randomly are arranged in the product, and the three-dimensional aesthetic effect imitating natural ice crystals is achieved. The method comprises the following steps: mixing lead-free glass particles with a calcium fluoride nucleating agent with a specific particle size, and filling a mixture into a special mold with a three-layer composite structure and a temperature monitoring function; and executing a four-stage programmed thermal regulation including melting homogenization, nucleation cooling, isothermal crystallization and super-slow multi-step annealing, wherein the melting and heat preservation time and the maximum thickness of the product meet the quantitative relation of t = k.H. Through systematic collaboration of materials, molds and processes, the technical problems that crystallization in large-size glass is not uniform and cracking is easily caused by thermal stress are solved, high yield and stable mass production of products of 500 kg or above are achieved, and the method is suitable for the fields of high-end buildings, art devices and decoration.

The present application relates to a kind of polyethylene terephthalate foamed materials and its preparation method, the preparation method includes the following steps: polyethylene terephthalate material is heat pressed, and the preform of molten state is obtained;The preform of molten state is treated with melt isothermal crystallization and quenching, and sheet material is obtained;And the sheet material is treated with foaming, and polyethylene terephthalate foamed material is obtained.The present application uses melt isothermal crystallization treatment, can improve the melt strength in the foaming process of polyethylene terephthalate, strengthens its foaming performance, simultaneously can also be realized by strengthening bubble nucleation and controlling bubble growth to adjust the bubble morphology of foamed material, so can obtain the polyethylene terephthalate foamed material of bubble size uniform and controllable foaming ratio.

The present application relates to a kind of polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolyester foamed material and its preparation method, the preparation method includes the following steps: polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolyester material is heat pressed, and the preform of molten state is obtained;The preform of molten state is treated with melt isothermal crystallization and quenching, and sheet material is obtained;Sheet material is treated with foaming, and polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolyester foamed material is obtained.The present application uses melt isothermal crystallization treatment, can improve the melt strength in the foaming process of polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolyester, strengthens its foaming performance, simultaneously can also be realized by strengthening bubble nucleation and controlling bubble growth to adjust the bubble morphology of foamed material, so polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolyester foamed material with uniform bubble size and controllable foaming ratio can be obtained.

Heat-shrinkable polyester film, derived from a first polyester resin and a second polyester resin as a plurality of polyester resins exhibiting different crystallinity, which are reaction products of a polyvalent carboxylic acid and a polyalcohol, wherein the heat-shrinkable polyester film fulfills the following features (A) to (E): (A) the first polyester resin is an amorphous polyester resin in which the polyvalent carboxylic acid contains at least terephthalic acid, and if a total amount of the polyalcohol is assumed to be 100 mol%, the reaction amount of ethylene glycol is in the range of 50 mol% or more and below 90 mol%; (B) the second polyester resin is a crystalline polyester resin in which the polyvalent carboxylic acid contains at least terephthalic acid, and if the total amount of the polyalcohol is assumed to be 100 mol%, a reaction amount of ethylene glycol is 90 mol% or more; (C) the heat-shrinkable polyester film is a heat-shrinkable polyester film which, when an isothermal crystallization measurement is performed by DSC at 150 °C, including a cooling process at a constant temperature, an exothermic peak occurs within 12 minutes of the start, including the cooling process time; (D) the heat-shrinkable polyester film is a heat-shrinkable polyester film in which, when an isothermal crystallization measurement is carried out by DSC at 150 °C, including a cooling process at a constant temperature, the amount of heat corresponding to the obtained exothermic peak area is in the range of 5 to 35 J / g; and (E) the heat-shrinkable polyester film is a heat-shrinkable polyester film in which a thermal shrinkage ratio in one principal shrinkage direction, measured under the thermal shrinkage conditions of immersion in hot water at 80 °C for 10 seconds, is in the range of 20% to 60%, wherein a weight-based mixing ratio of the first polyester resin / second polyester resin is in the range of 20 / 80 to 80 / 20, wherein the mass of the agglomerates as blockage resistance according to APR Document Code: PET-S-08 is less than 5%, and wherein the thickness of the heat-shrinkable polyester film is 25 to 70 µm.

The invention relates to a non-isothermal heat treatment process of Fe-based amorphous alloy and the alloy, and the method comprises the following steps: establishing a database, and collecting data of a non-isothermal crystallization process of the Fe-based amorphous alloy; establishing a machine learning model; a series of optimal machine learning models are adopted to establish the relationship among the components, the process and the performance of the Fe-based amorphous alloy; according to the prediction and verification of the optimal non-isothermal heat treatment process, the optimal non-isothermal heat treatment process of the Fe85.5 B8.5 Si2P2C2 amorphous alloy and the classic FINEMET alloy is predicted; and preparing the high-performance Fe-based amorphous and nanocrystalline dual-phase alloy, and annealing based on the predicted optimal heat treatment process. The soft magnetic performance of the Fe-based amorphous nanocrystalline alloy can be effectively improved through variable-temperature heat treatment.

A method for improving the nucleation of the γ phase in polyvinylidene fluoride (PVDF), a γ phase PVDF dielectric film based on the nucleation method, and a preparation method thereof are disclosed. The method involves using ceramic powder in the PVDF film material to enhance the nucleation ability of the γ phase crystals, improve the hydrophilicity of the PVDF film, and enhance the high-temperature dielectric properties of the PVDF film material. The dielectric film raw materials include 0-0.2 parts of ceramic powder (NBT), 10 parts of polyvinylidene fluoride (PVDF), and 200-204 parts of N,N-dimethylformamide (DMF). The preparation method is as follows: 1) Using N,N-dimethylformamide... 1) Prepare a 5% ceramic powder / polyvinylidene fluoride solution using amide as a solvent; 2) Drop the solution from step 1) onto a glass slide and cure it into a film in a vacuum oven at 68-72℃; 3) Melt the cured film obtained in step 2) on a hot stage at 200℃-220℃ to eliminate thermal history, and then rapidly cool it to 150-170℃ for isothermal crystallization until the blended film is completely crystallized; The preparation method of the γ-phase polyvinylidene fluoride dielectric film of the present invention is simple, convenient to operate, and has excellent performance, such as high temperature resistance, corrosion resistance, and strong piezoelectricity and ferroelectricity.

The invention belongs to the technical field of high polymer materials, and particularly relates to a crystallization regulation and control method of star-shaped polycaprolactone, a polycaprolactone film and application of the polycaprolactone film. The crystallization regulation and control method comprises the following steps: dissolving star-shaped polycaprolactone in toluene to obtain a film forming solution; carrying out melting heat treatment on the film-forming liquid after film formation, and then transferring to a crystallization temperature environment for isothermal crystallization; wherein the formation and growth rate of the polycaprolactone girdle spherocrystals is regulated and controlled by changing the arm number, crystallization temperature and formed film thickness of the star-shaped polycaprolactone. According to the invention, polycaprolactone with a star-shaped topological structure is used, the formation of the annulus spherocrystal, the bandwidth of the annulus spherocrystal and the growth rate of the annulus spherocrystal can be regulated and controlled by changing the arm number, the crystallization temperature and the film thickness, the method is simple, other substances do not need to be added, the preparation conditions are mild and controllable, the operation is convenient, and the method is suitable for industrial production. Pure polycaprolactone materials with different annulus spherocrystal bandwidths and growth rates can be obtained, and application of the pure polycaprolactone materials as special optical materials becomes possible.

This application relates to a high-melting-point, high-whiteness methyl octabromoether flame retardant composition and its preparation method, belonging to the fields of fine chemicals and flame retardant preparation technology. The method includes: etherifying tetrabromobisphenol A, sodium hydroxide, and allyl chloride; purifying the mixture by isothermal crystallization at 30–50°C to obtain a tetrabromoether intermediate; dissolving the intermediate in dichloromethane and reacting it with bromine at 10–40°C; and finally, obtaining the finished product through post-treatment. This invention effectively removes impurities such as monoethers through a specific intermediate crystallization process, and avoids overheating and oxidation side reactions by combining low-temperature bromination and optimized solvent ratios. The obtained flame retardant has a melting point ≥106°C, whiteness R457 ≥92, and bromine content ≥67%, exhibiting advantages such as good thermal stability, low volatility, and high purity. The process conditions are mild and suitable for industrial production.

The invention provides a mixed matrix membrane with an organic metal framework continuous passage as well as a preparation method and application of the mixed matrix membrane, and belongs to the field of high polymer materials and gas separation membranes. The mixed matrix membrane is composed of a highly continuous organometallic framework and an amorphous polyoxyethylene body. The invention also provides a preparation method of the mixed matrix membrane with the organic metal framework continuous passage. Polyethylene oxide has the characteristic of easy crystallization, in the isothermal crystallization process, a nanoscale organic metal framework, polyethylene glycol diacrylate and a photoinitiator can be discharged to an amorphous region of the organic metal framework, a highly continuous organic metal framework channel is formed, and then photo-crosslinking treatment is carried out to form a crosslinked amorphous network, so that the organic metal framework and the polyethylene glycol diacrylate are subjected to heat treatment to form an organic metal framework. And the crystallinity of polyoxyethylene is reduced while a continuous organic metal framework channel is fixed, so that the amorphous state is kept after high-temperature quenching.

The application discloses a preparation method of a high-thermal-stability high-molecular micro-nano structure, which comprises the following steps: preparing a solution by taking polyethylene oxide as raw material and toluene as solvent; preparing a polyethylene oxide ultrathin film sample by adopting a spin coating method; firstly, performing melt isothermal crystallization on the polyethylene oxide ultrathin film sample under a nitrogen protection atmosphere, wherein the crystallization temperature is T c1 , and the crystallization time is t c1 ; and then, further increasing the crystallization temperature to T c2 , continuing crystallization for t c2 ; and the micro-nano structure constructed by the method has high thermal stability, the thermal stability of the polymer ultrathin film is controlled from the nanometer scale, and the application of the polymer ultrathin film in the fields of sensors, thermal etching, drug release and the like is widened.

The invention relates to the technical field of high polymer materials and polyester synthesis, in particular to polyethylene naphthalate resin and a preparation method and application thereof.According to the method, a small amount of flexible long-chain diol monomers are introduced into a PEN prepolymer molecular chain in the liquid phase polymerization stage, so that an obtained prepolymer has high chain segment flexibility; then carrying out isothermal crystallization to preferentially grow into a loose beta crystal structure; and finally, carrying out solid-phase polycondensation reaction to obtain the polyethylene naphthalate resin. Wherein a flexible chain segment is introduced, and the crystallization behavior of a PEN prepolymer is regulated, so that a beta crystal structure with a continuous amorphous channel is more easily formed, the rapid diffusion and removal of an ethylene glycol byproduct are promoted, the solid phase polycondensation rate is obviously accelerated, the molecular weight is improved, and the obtained PEN resin has excellent thermal stability, color and luster and mechanical properties; the method is suitable for preparing high-strength and high-modulus fibers and engineering plastics, and solves the problems of long process period and poor controllability in the PEN preparation process in the prior art.

The invention provides a high molecular weight polyethylene naphthalate resin and a solid phase polycondensation preparation method thereof, the method takes dimethyl 2, 6-naphthalate, ethylene glycol and a diol monomer with a large steric hindrance side group as raw materials, and the high molecular weight polyethylene naphthalate resin is obtained through the steps of pre-polymerization (liquid phase polymerization), isothermal crystallization treatment and solid phase polycondensation treatment; according to the invention, a large steric hindrance side group is introduced in a pre-polymerization stage, and subsequent crystallization regulation and control and solid phase polycondensation processes are combined, so that the polycondensation reaction can be effectively promoted, the molecular weight of the PEN resin is obviously improved, and a high molecular weight product with the number-average molecular weight of 46265-58421 g / mol is finally obtained; the method is simple in process step, and the prepolymer obtained by prepolymerization can be directly extruded and diced to form particles with uniform particle size, so that the subsequent process operation is facilitated; reaction conditions involved in each step are easy to control, the method can adapt to conventional industrial production equipment, and the product is stable in performance and good in repeatability and has a wide industrial application prospect.

The invention discloses a production process for preparing copper acetate from pure copper by a one-step method, which belongs to the technical field of copper acetate, and comprises the following steps: adding modified copper powder into a reaction kettle, adding an acetic acid aqueous solution in a nitrogen atmosphere, stirring for pre-dispersion, adding a compound additive, and continuously stirring; raising the temperature and stirring at normal pressure, and supplementing an acetic acid aqueous solution during stirring; performing centrifugal separation to obtain copper acetate coarse crystals and mother liquor, and performing filtration and cation exchange resin column treatment on the mother liquor for recycling; adding water into the coarse crystal for recrystallization, heating, stirring and filtering, cooling and crystallizing the filtrate, centrifuging, and carrying out vacuum drying on the final crystal to obtain copper acetate. The whole process does not produce by-products such as sodium sulfate and alkali-containing wastewater, and the mother liquor can be recycled after being filtered and treated by the cation exchange resin column, so that the raw material consumption and the waste liquor discharge are reduced, the wastewater treatment cost is effectively reduced, and the development concept of green chemical industry is met.

The present application provides a kind of detection method of ash in asphalt.The detection method includes: step S1: raw materials including asphalt and dispersant are heated and mixed in sequence to obtain melt;Step S2: melt is crystallized to obtain asphaltene crystal;Crystallization treatment includes temperature drop and isothermal crystallization treatment in sequence;The temperature drop rate of temperature drop is ≤5℃ / min;Step S3: asphaltene crystal is phase separated to obtain crystalline phase;Step S4: crystalline phase is ashed to obtain ash;The temperature of ashing treatment is ≤200℃;Step S5: ash is detected to obtain the composition and mass content of ash.The detection method of the present application can realize efficient enrichment of ash and very low background interference, can detect most of the trace metal elements in ash, and has good accuracy and repeatability, thereby better meeting the quantitative detection needs of high-quality asphalt for very low ash content.

This invention belongs to the field of polymer testing and analysis technology, specifically a method for rapidly characterizing the chain structure of metallocene linear low-density polyethylene. The method includes: determining the crystallization curve of a sample under non-isothermal crystallization conditions using a differential scanning calorimeter; decomposing the crystallization curve into three characteristic regions: region A associated with the crystallization of longer methylene sequences; region C associated with the crystallization of very short methylene sequences; and the remaining region B associated with the crystallization of intermediate-length methylene sequences. The proportion of each region's area in the total crystallization area is calculated based on the area of ​​each of the three regions. I A , I B and I C ;use I A , I B and I C The magnitude of the value can characterize the relative content of long, short, and very short crystallizable methylene sequences in the mLLDPE, thereby assessing the uniformity of comonomer distribution along its macromolecular chain. This invention features a simple, fast, and low-cost analytical process, making it particularly suitable for quality management in mLLDPE production and application companies.

Provided is a polyarylene sulfide resin composition that has excellent resistance to heat and humidity and molding properties without reducing mechanical strength and the like. More specifically, the present invention is characterized by comprising a polyarylene sulfide resin, glass fibers that have been surface-treated with a sizing agent comprising an epoxy resin and a polyether resin, and a silane coupling agent having a functional group, the total content of the epoxy resin and the polyether resin in the aforementioned sizing agent being 65 to 100 mass%, and the isothermal crystallization time of the polyarylene sulfide resin composition being 9 seconds or less.

The application discloses a method for regulating and controlling micro-nano patterns of crystalline block copolymer, which comprises the following steps: a solution of polyethylene oxide-poly(2-vinylpyridine) (PEO-P2VP) block copolymer is spin-coated on a silicon wafer to obtain a PEO-P2VP film; the spin-coated film is annealed at different temperatures, and then is placed into a Linkam hot stage to perform melt isothermal crystallization; by changing the annealing temperature, the melt temperature of melt heat treatment and the melt time, the lamellar patterns in the PEO-P2VP film can be regulated and controlled. b The PEO-P2VP block copolymer is poly(ethylene oxide)-poly(2-vinylpyridine). b The PEO-P2VP block copolymer is poly(ethylene oxide)-poly(2-vinylpyridine). b The PEO-P2VP block copolymer is poly(ethylene oxide)-poly(2-vinylpyridine). b The PEO-P2VP block copolymer is poly(ethylene oxide)-poly(2-vinylpyridine). The method has the advantages of simple operation, low equipment requirement, and the ability to form nano-pattern arrays with controllable density, size and morphology on a large area, which opens up new possibilities for the application of multifunctional nano materials, and has extremely important significance for the future development of block copolymer materials.

The invention discloses a preparation method and application of a carbon fiber / polypropylene composite material with a self-reinforced interface, and belongs to the technical field of composite materials. The preparation method of the carbon fiber / polypropylene composite material with the self-reinforced interface comprises the following steps: impregnating carbon fibers in molten polypropylene; cooling to a pre-forming temperature, and stretching the carbon fibers at a rate of 40-300 [mu] m / s; continuously cooling to a forming temperature, and carrying out isothermal crystallization; and cooling to room temperature to obtain the carbon fiber / polypropylene composite material with the self-reinforced interface. The contents of alpha and beta crystal forms in an interface transverse crystal are regulated and controlled in a manner of stretching the carbon fiber at different rates and giving a shear force to a matrix in a pre-forming stage, so that the interface bonding performance of the carbon fiber / polypropylene composite material is improved, the designability and the regulation and control of the comprehensive performance of the carbon fiber / polypropylene composite material are improved, and the industrial application diversity is met.

The invention relates to bio-based long-carbon-chain nylon based on pentamethylene diamine and a preparation method thereof.The bio-based long-carbon-chain nylon is prepared through the following steps that A, pentamethylene diamine and binary acid are subjected to a water bath reaction, and precursor salt is prepared; and B, adding the precursor salt and a reaction aid into a reaction kettle to perform a prepolymerization reaction under the condition of a catalyst through a melt polycondensation method, and then performing a final polymerization reaction to obtain the catalyst. The mechanical property test result of the prepared bio-based long carbon chain nylon shows that the yield strength of the bio-based long carbon chain nylon is 54-60 MPa, the elongation at break can reach 219-255%, and the bio-based long carbon chain nylon has certain strength and good toughness; and the non-isothermal crystallization activation energy [delta] E is-144.09 to-216.79 KJ / mol.

An unnucleated metallocene polypropylene having: (i) a melting temperature of from about 153 °C (307 °F) to about 183°C (361.4 °F); (i) a heat deflection temperature of from about 98.9°C (210°F) to about 129.4 °F (265°F); (iii) a lower temperature bound for the isothermal crystallization temperature of from about 120 °C (248°F) to about 154°C (309.2°F); (iv) a flexural modulus of from about 200 kpsi to about 330 kpsi; and (v) a tensile modulus of from about 220 kpsi to about 325 kpsi; and (vi) a tensile strength at yield of from about 4800 psi to about 5900 psi.