The invention discloses a preparation method of a low-turbidity bisphenol A type cyanate ester prepolymer. The preparation method of the low-turbidity bisphenol A type cyanate ester prepolymer comprises the steps that diphenol propane, cyan chloride and triethylamine are dissolved in a solvent for participating in a reaction, and recrystallization is carried out to obtain the low-turbidity bisphenol A type cyanate ester prepolymer; reaction liquid by vaporific injection is in fully contact with a catalyst in an internal atomization chamber through an atomization reaction device, the conversionrate of the bisphenol A type cyanate ester prepolymer is increased by 85-95%, and product turbidity and purification difficulty are effectively reduced; and a phase transfer catalyst is mixed with ethyl alcohol to form a catalyst for participating in a reaction, local polymerism taking the catalyst as the center cannot occur at an initiating stage, gels and solid particles cannot be formed, so that reactants are sufficiently in contact with each other, the reaction is more thorough, the turbidity of a reaction system is greatly reduced, the purification difficulty is further reduced, and theturbidity of the obtained bisphenol A type cyanate ester prepolymer is less than or equal to 5 FTU after detection, and is greatly superior to the standard of being less than or equal to 10 FTU in theprior art.

Preparation method of low-turbidity bisphenol A type cyanate ester prepolymer

A preparation method of an aliphatic isocyanate homopolymer includes the following steps: isocyanate is added into a reaction kettle with a multi-micropore inner coil pipe, and after technological conditions requiring for a reaction are reached, a catalyst composite system formed by a quaternary ammonium salt and an inert alcohol solvent is blown into the reaction system by an inert gas with a certain pressure by a high pressure atomization way, wherein the catalyst composite system is added completely at right time. The method can quickly mix the catalyst composite system and isocyanate evenly, improves the utilization rate of the catalyst, reduces the amount of the catalyst, and completes the reaction process under mild and exothermic conditions.

Preparation method of aliphatic isocyanate homopolymer

The invention discloses a cyclohexyl isocyanate synthesis process. The process includes steps: checking complete equipment; feeding methylbenzene and cyclohexylamine into a synthesis kettle, stirring,feeding hydrogen chloride, controlling the temperature at 30 DEG C, stopping feeding of hydrogen chloride after 8-12h, feeding phosgene into the synthesis kettle, feeding nitrogen after reaction, driving gas for 10h, sampling, analyzing, and discharging crude ester into a crude ester storage tank after qualification is determined. Excessive phosgene is kept in a reaction process of phosgene and cyclohexylamine in a hydrogen chloride environment, and complete reaction of cyclohexylamine is guaranteed; after reaction, nitrogen is directly fed to drive out and absorb phosgene, so that environmental pollution caused by phosgene directly entering the environment is avoided; by distillation recovery of methylbenzene in crude cyclohexyl isocyanate, economic benefits are improved, purity of cyclohexyl isocyanate is evidently improved, the cyclohexyl isocyanate yield is 96% or above while the content reaches 98% or above, the amine content is smaller than 0.2%, and the methylbenzene content issmaller than 0.5%.

Cyclohexyl isocyanate synthesis process

The invention relates to a method for preparing a polyisocyanate curing agent based on IPDI (Isophorone Diisocyanate). According to the method, the content of a nitrile compound in IPDI in a raw material is controlled to be less than 0.02wt%, meanwhile an ammonia solution or a micromolecule ammonia solution with at least one hydrogen atom is adopted as a terminator, a reaction liquid is subjectedto heating treatment, then the color number of a final curing agent product is less than 20hazen, and meanwhile the storage stability of the product is improved.

Method for preparing polyisocyanate curing agent based on IPDI (Isophorone Diisocyanate)

The invention provides a preparation method and application of a polyurethane optical resin. The preparation method comprises the step of carrying out a polymerization reaction on a raw material composition containing isocyanate and a polythiol compound to obtain the polyurethane optical resin, wherein the content of the dimer structure polymer of isocyanate present in isocyanate used in the raw material composition is controlled to be less than or equal to 4 wt%, preferably less than or equal to 3 wt%, further preferably less than or equal to 2.5 wt%, and more preferably less than or equal to1.6 wt%. According to the preparation method of the polyurethane optical resin, the polyurethane optical resin can be well manufactured, and the optical deformation occurrence rate of products can beeffectively reduced.

Preparation method and application of polyurethane optical resin

A preparation method of a low-turbidity isocyanate oligomer comprises the following steps: a) carrying out a trimerization reaction on an isocyanate monomer in a first dynamic reaction kettle under the catalysis of a composite catalyst, and controlling the conversion rate of the isocyanate monomer in the first dynamic reaction kettle to reach 20-60 wt% in order to obtain a reaction solution (1); b) atomizing the reaction solution (1) in a second atomization reaction kettle, and reacting the atomized reaction solution with the composite catalyst in an aerosol form to obtain a reaction solution (2); c) allowing the reaction solution (2) to enter a third dynamic reaction kettle, and terminating the reaction under the action of a catalyst poison to obtain a reaction solution (3); and d), separating and recovering the isocyanate monomer from the reaction solution (3) to obtain the low-turbidity isocyanate oligomer product The method substantially shortens the reaction time, reduces solid/gel particles in the reaction solution, and allows the low-turbidity isocyanate oligomer product to be obtained

Preparation method of low-turbidity isocyanate oligomer

The invention discloses a phosgenation reactor and a method for preparing an isocyanate monomer by using the phosgenation reactor The phosgenation reactor comprises an inner material inlet pipe, an outer material inlet pipe, a mechanical stirring rotation shaft, a rotation area and a kettle body, wherein the rotation area comprises a support structure, a rotation area filler block, an upper material outlet device and a lower material outlet device, the inner material inlet pipe and the outer material inlet pipe are coaxially arranged from inside to outside, the upper material outlet device and the lower material outlet device are arranged in parallel, are connected through the support structure, and are respectively communicated to the outer material inlet pipe and the inner material inlet pipe, the rotation area filler block is filled between the upper material outlet device and the lower material outlet device, the upper material outlet device is connected to the mechanical stirringrotation shaft, and the kettle body is provided with a gas phase material outlet, a liquid phase material outlet, a gas phase material inlet and a liquid phase material inlet According to the present invention, by pre-treating the hydrochloride solution in the reactor, the salt forming concentration and the quality of the hydrochloride solution are improved while the rapid removal of hydrogen chloride gas during the phosgenation is achieved, such that the generation of chlorination by-products is effectively reduced, and the product separation difficulty is reduced

Phosgenation reactor and method for preparing isocyanate monomer by using phosgenation reactor

The invention relates to a salicyldenaminato schiff base metal complex catalyst and a preparation method thereof. The catalyst comprises the following components: (A) a salicyldenaminato schiff base ligand, (B) a transition metal compound which can be coordinated with the salicyldenaminato schiff base ligand, and (C) alkali metal or alkaline-earth metal salt. The catalyst is used for catalyzing self-polymerization of diisocyanate in order to prepare a polyisocyanate curing agent, the problem of higher content of high polymers in the curing agent which is prepared by a direct synthesis method is solved, and at the same time products with excellent molecular weight distribution are obtained, and free monomers in the products are lower than 0.3wt%.

Salicyldenaminato schiff base metal complex catalyst as well as preparation method thereof and application thereof

The invention provides a method for preparing vitamin E acetate. The method has the characteristic of high product selectivity; a catalyst used in the method provided by the invention facilitates recovery and reutilization and has less corrosion to equipment; and a product has good stability. The method for preparing the vitamin E acetate provided by the invention prepares the vitamin E acetate through a reaction of 2,3,5-trimethylhydroquinone diester and isophytol, wherein the reaction is carried out in the presence of the catalyst; and with a molecular sieve as a carrier, the catalyst is prepared by loading Bronsted acid, metal halide, metallocene and a metal element onto the molecular sieve.

Method for preparing vitamin E acetate

Popular Tasks used by Researchers

How can I help with your research?

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

We encountered an error while loading the panel. Please try refreshing the page.

Something went wrong

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

Anyone with the link can view this chat. You can switch it back to private anytime.

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Qiao Xiaofei

Author Tools

Chat about Author