15 results about "Telomerization" patented technology

The application relates to the technical field of fluorine-containing iodoalkane preparation, in particular to a preparation method of high-carbon-number diiodoperfluoroalkane, which comprises the following steps: reacting tetrafluoroethylene and elemental iodine to generate diiodotetrafluoroethane; and under the action of a catalyst, the diiodotetrafluoroethane is subjected to telomerization reaction with tetrafluoroethylene to generate high-carbon-number diiodoperfluorobutane and diiodoperfluorohexane; and the catalyst is a metal nickel catalyst supported on silicon dioxide. The metal nickel catalyst supported on silicon dioxide is used to make the diiodotetrafluoroethane and the tetrafluoroethylene subjected to telomerization reaction to obtain diiodoperfluoroalkane with higher carbon number. The application has the advantages of simple process, low reaction temperature and the like, and can significantly improve the yield of diiodoperfluorobutane and diiodoperfluorohexane.

The invention provides a method for preparing fluoroalkanol, and belongs to the field of organic synthesis. In the method for preparing the fluoroalkanol, provided by the invention, a compound H (CF2CF2) 4CH2OH is prepared through telomerization reaction of tetrafluoroethylene and methanol in the presence of an initiator, a product distribution regulator and an acid-binding agent, the product distribution regulator is an organic salt of a rare earth metal, and when the reaction is started, the partial pressure of tetrafluoroethylene in a reaction container is 1.0-1.6 MPa, and the partial pressure of tetrafluoroethylene in the reaction container is 1.0-1.6 MPa. The reaction temperature is 110-150 DEG C; as the product distribution regulator and the acid-binding agent are added in the reaction, not only can the overall conversion rate of the reaction be effectively improved, but also the selectivity of the target compound H (CF2CF2) 4CH2OH can be improved, and the target compound can be obtained with higher yield.

The application provides a method for preparing dimethyl silicone oil, which comprises mixing low-molecular-weight hydroxyl-terminated polydimethylsiloxane, a methyl end-capping agent, a polycondensation telomerization agent and a phosphorus nitride catalyst, and sequentially performing normal-pressure polycondensation telomerization and negative-pressure polycondensation telomerization to obtain dimethyl silicone oil. The polycondensation telomerization agent added in the preparation method can effectively control the polycondensation rate, and dimethyl silicone oil with different viscosities can be prepared, while the viscosity peak caused by polycondensation is avoided, and the advantage is more obvious, especially for high-viscosity products. The dimethyl silicone oil prepared by the preparation method has the advantages of low ring content, especially low content of large-ring by-products, and low metal ion content, so that the application scenarios are wider. In addition, the polycondensation time of the preparation method is short, the quality is improved, the production capacity is improved, and the requirement for equipment is low.

The application provides a method for preparing hexafluoropropylene oxide dimer and pentafluoropropionic acid through photocatalytic telomerization, and relates to the technical field of organic synthesis, and comprises the following steps: performing photocatalytic reaction on a rectification residue of hexafluoropropylene oxide dimer to continuously pyrolyze and telomerize, so that hexafluoropropylene oxide dimer and pentafluoropropionic acid are obtained; the components of the rectification residue include hexafluoropropylene oxide polymer CF3CF2CF2O[CF(CF3)CF2O] n CF(CF3)COF, n=0~5; the catalyst used in the photocatalytic reaction comprises alkali metal fluoride loaded on activated carbon. The application resources the hexafluoropropylene oxide polymer to hexafluoropropylene oxide dimer and pentafluoropropionic acid through telomerization, so that by-product waste liquid is fully resourced, and the application has the advantages of green economy; meanwhile, the reaction condition is mild, the conversion rate is high, the yield is high, the time is short, and the application is easy to industrialize.

A method for preparing 2,3,3,3-tetrafluoropropene by a two-step method, the method comprising: A1. a telomerization step: preparing 3-chloro-1,1,1,2-tetrafluoropropane by pressure telomerization reaction of monofluoromonochloromethane and trifluoroethylene under the action of a telomerization catalyst; the telomerization catalyst is a Lewis acid catalyst or a mixed catalyst of a Lewis acid catalyst and dichloromethane; A2. a dehydrochlorination step: 3-chloro-1,1,1,2-tetrafluoropropane is dehydrochlorinated under the catalysis of activated carbon to obtain 2,3,3,3-tetrafluoropropene. The present application has the advantages of simple process, high product selectivity, mild reaction conditions and the like.

The application belongs to the field of organic silicon synthesis, and particularly relates to a preparation method of low ring body and ultra-low viscosity dimethyl silicone oil, wherein the viscosity of the dimethyl silicone oil is less than or equal to 5 cSt; the preparation method comprises the following steps: firstly, placing alpha, omega-dihydroxyl polysiloxane linear body, a polymerization inhibitor and a catalyst in a vacuum condition to perform a condensation dehydroxylation reaction, so as to obtain a prepolymer; then, adding an end-capping agent to the prepolymer to perform an equilibrium telomerization; after the reaction is completed, adding a terminating agent and a catalyst quenching agent, so as to obtain the ultra-low viscosity dimethyl silicone oil. The preparation method is simple in process, mild in preparation condition, easy to realize, free of waste water and waste salt, green and environment-friendly, and suitable for industrialized production.

This invention discloses a metal-carbon composite catalyst and method for the continuous preparation of 1,1,1,3-tetrachloropropane. The main component of the catalyst is Cu-Ni-Cl-C / Fe, and the catalyst preparation process includes four steps: mixing, carbonization, displacement, and loading. The catalyst of this invention can efficiently catalyze the telomerization reaction of carbon tetrachloride and ethylene, generating the target product 1,1,1,3-tetrachloropropane with high selectivity. The catalyst exhibits stable performance, maintaining good catalytic effect even after five repeated uses. The conversion rate of carbon tetrachloride and ethylene reaches over 95%, and the selectivity of 1,1,1,3-tetrachloropropane is greater than 98.5%.

This invention belongs to the field of organic synthesis technology, specifically relating to a method for preparing 1,1,3,3,3-pentafluoropropylene. This invention designs a perovskite-type catalyst doped with noble metals or synergistically constructs a supported metal catalyst. Through a collaborative mechanism where the support provides strong Lewis acidity and fluorination activity, while the noble metal provides dehydrogenation activity, the interfacial interactions and reaction matching of the catalytic system are precisely controlled. This allows for highly efficient catalysis of the integrated "telomerization-fluorination-dehydrogenation" reaction of vinyl chloride (CHCl=CH2), carbon tetrachloride (CCl4), and hydrogen fluoride (HF). The reaction can be carried out continuously in the same reactor and with the same synergistic catalyst system, without the need to change equipment or catalysts, resulting in outstanding production efficiency. Furthermore, the selectivity and controllability of the reaction conditions are significantly optimized, enabling high-selectivity and high-yield synthesis of the target product under mild conditions. Simultaneously, it achieves the resource utilization of industrial waste carbon tetrachloride, representing a major technological breakthrough in terms of raw material cost, process simplification, and environmental friendliness.

This invention belongs to the field of organosilicon chemical synthesis technology, and discloses a segmented preparation method for low-cyclic polysiloxanes and a segmented polymerization reactor. The method includes: raw material pretreatment, segmented polymerization reaction, termination and purification, and post-treatment. The segmented polymerization reaction is carried out in an integrated segmented polymerization reactor, and includes, in sequence: 1) initiation of polycondensation under ultrasonic action; 2) end-capping polymerization under high shear action; 3) homogenization reaction under thermal equilibrium conditions. The segmented polymerization reactor integrates an ultrasonic dispersion reaction zone, a high-shear polymerization reaction zone, and a thermal equilibrium adjustment zone from top to bottom. Compared with the prior art, this invention effectively reduces the cyclic content and metal ion residue in the product through segmented reaction and refined control, improves product purity, uniformity of molecular weight distribution, and reaction efficiency, and is suitable for the continuous production of high-quality polysiloxanes.

The invention discloses a preparation method of (E)-1, 1, 1, 2, 2, 5, 5, 6, 6, 6-decafluorohexyl-3-ene, and the preparation method comprises the following steps: carrying out telomerization reaction on 1, 1-difluoroethane, tetrafluoroethylene and HF in the presence of a catalyst to prepare 1, 1, 1, 2, 2, 5, 5, 6, 6, 6-decafluorohexane, and then carrying out halogenation and dehydrohalogenation reaction to prepare (E)-1, 1, 1, 2, 2, 5, 5, 6, 6, 6-decafluorohexyl-3-ene. The preparation method provided by the invention has the advantages of cheap and easily available raw materials and high product selectivity.

This invention discloses a process for synthesizing tetrachloropropene from carbon tetrachloride, comprising the following steps: S1) Preparation of 1,1,1,3-tetrachloropropane via telomerization reaction. Carbon tetrachloride is used as a raw material, and ethylene is subjected to telomerization reaction under the catalysis of a metal-carbon composite catalyst. The metal-carbon composite catalyst is prepared by a four-step process of mixing, carbonization, displacement, and loading, and directionally catalyzes the generation of crude 1,1,1,3-tetrachloropropane. This application significantly improves the catalytic activity and product selectivity of the telomerization reaction between carbon tetrachloride and ethylene by employing a self-prepared metal-carbon composite catalyst. It can directionally generate the 1,1,1,3-tetrachloropropane intermediate, effectively suppressing side reactions and improving the yield of the target product and the conversion rate of raw materials. This catalyst, prepared by a four-step process of mixing, carbonization, displacement, and loading, has a stable structure, long service life, and can be recycled multiple times, significantly reducing catalyst consumption and production costs, and solving the problems of poor selectivity and insufficient stability of traditional catalysts.

The invention relates to the technical field of high polymer materials, in particular to a preparation method of carbon dioxide-based polyol, which comprises the following steps: by taking 4-allylcatechol as an initiator, reacting epoxypropane and carbon dioxide gas under the action of a catalyst to obtain carbon dioxide-based polyol with a structure as shown in a formula I; in the formula I, x and m are the number of repetitive units of carbonic ester units; y and n are the number of repetitive units of ether units; 3 < = x + m < = 15, 2 < = y + n < = 30. The novel initiator 4-allylcatechol is introduced into the telomerization reaction of propylene oxide and carbon dioxide through a one-pot synthesis method, the double-bond functionalized carbon dioxide-based polyol can be efficiently prepared, the operation is simple and convenient, and the chain length and the structure of the double-bond functionalized carbon dioxide-based polyol are adjustable.

The invention provides a synthesis method of octadiene monomethyl ether, in the synthesis method, methanol and butadiene are used as reactants for telomerization reaction, an organic amine compound is added into a reaction system as an additive, and organic amine can accelerate the coordination dissociation process of palladium ions in the telomerization reaction process and also has reducibility; divalent palladium ions in the catalyst can be rapidly reduced into zero-valent palladium in an alkaline environment, and the efficiency of telomerization reaction is improved by promoting coordination dissociation and reduction processes of the palladium ions.

The invention discloses CO2-based thermoplastic polyurethane and a preparation method thereof. The method adopts a one-pot two-step reaction and comprises the following steps: firstly, performing ring-opening copolymerization on alpha-ethylidene-delta-vinyl-delta-valerolactone (EVP) (from telomerization of CO2 and 1, 3-butadiene) and a cyclic monomer (cyclic lactone or cyclic carbonate) to prepare unsaturated copolyester polyol with a side chain containing carbon-carbon double bonds; and taking the polyol as a soft segment, and reacting with diisocyanate and a chain extender to obtain the thermoplastic polyurethane. Controllable transformation of the material from a crystalline state to an amorphous state and from a plastomer to a high-elastic body is realized by regulating and controlling the EVP content (0-19 mol%). The obtained material can be selectively subjected to bulk depolymerization under the action of a catalyst, is efficiently recovered into EVP and a cyclic monomer, and has good chemical recovery performance. Meanwhile, side chain double bonds provide reaction sites for subsequent functionalization, so that the polymer has good application prospects in the fields of elastomers, adhesives, biomedical materials and the like.

The invention provides a preparation method of octadiene monomethyl ether. In the preparation method of the octadiene monomethyl ether, provided by the invention, after the telomerization reaction of methanol and butadiene, the reaction liquid is subjected to azeotropic separation and extraction liquid separation to obtain a high-purity product octadiene monomethyl ether, and the catalyst which is not separated in the azeotropic separation process can be recycled. The method realizes rapid separation of the product and the catalyst in a low-temperature environment, maintains the activity of the catalyst on the basis of obtaining the product octadiene monomethyl ether with relatively high purity, and has the advantages of rapid separation of the product, recycling of the catalyst, high product preparation efficiency and the like.