Synthesis and study of diols containing bisphenol fragments and of polymers produced on their basis

Papava, G. Sh.; Maisuradze, N. I.; Zarkua, Z. L.; Dokhturishvili, Nora; Sarishvili, Z. M.; Razmadze, G. B.; Виноградова, С. В.; Коршак, В.В.

doi:10.1002/actp.1988.010390814

Cited by 15 publications

(7 citation statements)

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“…Thus, to compare the reactivities of different diisocyanates toward alcohols is a difficult task because of the lack of finding the same experimental conditions for the diisocyanates to be compared. Furthermore, various experimental tools ranging from dilatometry and titration of the free isocyanate groups 11,22,24 to instrumental methods including liquid chromatography, 16 UVVis and fluorescence spectroscopy 17,19 as well as FT-IR spectroscopy 30 are being used for monitoring the isocyanate-alcohol reactions.…”

Section: Introductionmentioning

confidence: 99%

New insight into the kinetics of diisocyanate‐alcohol reactions by high‐performance liquid chromatography and mass spectrometry

Nagy

Antal

Czifrák

et al. 2015

J of Applied Polymer Sci

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The uncatalyzed reactions of 2,4-TDI (2,4-toluenediisocyanate) and MDI (4,4 0 -diphenylmethane-diisocyanate) with alcohols including butan-1-ol, butan-2-ol, diethylene glycol monomethylether (DEGME) were studied by high-performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS). The reactions were carried out at different temperatures from 22 C to 75 C using high molar ratios of alcohols to diisocyanates. It was found that the first isocyanate group of the MDI reacts about 1.5 times faster with the alcohols than the second one. The relative reactivities of the isocyanate groups (para and ortho) of 2,4-TDI as a function of the temperature was also deduced. From the temperature dependence of the rate constants the apparent activation energies were determined. Furthermore, the dependence of the apparent rate constant on the concentration of alcohols was also investigated and a mechanism was proposed for the reaction of diisocyanates with alcohols.

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Section: Introductionmentioning

confidence: 99%

New insight into the kinetics of diisocyanate‐alcohol reactions by high‐performance liquid chromatography and mass spectrometry

Nagy

Antal

Czifrák

et al. 2015

J of Applied Polymer Sci

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“…One of the crucial parameters in these syntheses is the reactivity of the isocyanate groups toward the polyols. Thus, large efforts have been devoted so far to study the reaction kinetics of industrially important isocyanates including, e.g., 4,4′‐diphenylmethane‐diisocyanate (4,4′‐MDI) , toluene‐diisocyanete (TDI) , and hexamethylene diisocyanates with various alcohols using different reaction conditions and monitoring methods such as titration , UV–vis photometry combined with high‐performance liquid chromatography (HPLC) , fluorescence spectroscopy , and mass spectrometry . It is now generally accepted that aromatic isocyanates have higher reactivity than that of the aliphatic ones, and they are used in many polyurethane formulations.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of Uncatalyzed Reactions of 2,4′- and 4,4′-Diphenylmethane-Diisocyanate with Primary and Secondary Alcohols

Nagy

Kuki

et al. 2017

Int. J. Chem. Kinet.

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The kinetics of the uncatalyzed reaction of an industrially important 50/50 blend of isomers of 4,4′‐diphenylmethane‐diisocyanate (4,4‐MDI) and 2,4′‐diphenylmethane‐diisocyanate (2,4′‐MDI) with primary and secondary alcohols was studied using high‐performance liquid chromatography coupled with photodiode array detector. The alcohols such as 1‐propanol, 2‐propanol, 1‐hexanol, 2‐hexanol, 3‐hexanol, 1‐methoxy‐2‐propanol, and 3‐methoxy‐1‐propanol were used in high molar excess to diisocyanate in toluene at 80°C, and pseudo–first‐order dependences on the concentrations of 4,4′‐MDI and 2,4′‐MDI were found. Appropriate treatments of the kinetic data allowed us to determine the corresponding pseudo–first‐order rate constants. According to the kinetic results, the reactivity of the isocyanate group in the para‐position is about four to six times higher than that of the ortho‐positioned isocyanate group, depending on the reacting alcohol. Furthermore, the substitution effect, i.e., change in the reactivity of the free isocyanate group after the other has been reacted, was found for both 4,4′‐MDI and 2,4′‐MDI isomers. The differences in the reactivities of the isocyanate groups of 2,4′‐MDI and 4,4′‐MDI isomers before and after one of two isocyanate groups has been reacted are explained in terms of partial positive charges on the corresponding carbonyl carbon atom calculated by high‐level quantum chemical calculations. In addition, the UV‐spectral properties of the products obtained by quenching the reaction mixture with methanol are also discussed in light of practical implications.

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“…80 BHEPF is usually obtained by a multi-step procedure 81 or a one-step synthesis in the presence of concentrated sulfuric acid and 3-mercaptopropionic acid. 82 However, the above two synthetic methods suffer from some serious disadvantages: 1) Large amounts of acids result in the production of hazardous wastes which entails environmental pollution, and 2) the use of corrosive acids corrodes reactor walls.…”

Section: Acid-catalyzed Reactions By Timentioning

confidence: 99%

Design of High-Performance Heterogeneous Metal Catalysts for Green and Sustainable Chemistry

Kaneda¹,

Ebitani²,

Mizugaki³

et al. 2006

Bulletin of the Chemical Society of Japan

142

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This account reviews a novel approach to designing high-performance heterogeneous metal catalysts using hydroxyapatites, montmorillonites, and hydrotalcites as macroligands of active metal species for aerobic alcohol oxidations, carbon-carbon bond formations, and one-pot syntheses. The catalytic systems using the above heterogeneous catalysts offer significant benefits in achieving environmentally friendly organic syntheses aiming towards Green and Sustainable Chemistry. Furthermore, the present preparation method for the immobilization of metal species is strikingly simple and allows a strong protocol for creating various nanostructured and functionalized heterogeneous catalysts.Green and Sustainable Chemistry (GSC) is a revolutionary philosophy that aims to bring about a sustainable society by improvement of the safety and environmental aspects of chemical processes and reduction of the risks of chemical products to people and the environment.1 The emphasis is on eliminating waste at the source-primary pollution prevention-rather than finding incremental end-of-pipe solutions. This concept aims to solve the societal problems of the last century associated with the mass production and consumption of materials, and plays a prime role in providing a venous function in society, encouraging reuse and circulation of resources.One of the powerful solutions in the move toward GSC is the replacement of traditional synthetic methods using harmful stoichiometric reagents that produce vast amounts of waste with cleaner and simple catalytic alternatives with high atom efficiency 1a and low E-factors. 1b Catalytic chemistry, therefore, is of ever-increasing importance because catalysis is a key element in material transformations at atomic and molecular levels, which are an essential realm of chemistry and chemical processes.Our approach to GSC is to develop a highly functionalized heterogeneous metal catalyst based on the unique characteristics of natural layered inorganic materials such as hydroxyapatite, montmorillonite, and hydrotalcite, by using them as macroligands for metal species.2 We consider the above inorganic materials to be advanced nano-scaled catalyst supports allowing for the control of the location of catalytically active metal species, which can be found, for example, on the surface, among the layers, or in the interlayer space. Furthermore, these materials are capable of creating catalytically active metal species responsible for targeted organic transformations involving monomers, chain-like species or giant clusters. The creation of well-defined active metal sites on a solid surface, as characterized by X-ray absorption spectroscopy, not only opens up an avenue to materials that boost catalytic performance, but also aids in the understanding of the molecular basis of heterogeneous catalysis. Another advantage of these catalysts is the possibility of a one-pot synthesis based on a cooperative action by several immobilized active species on the solid surface as multifunctional catalysts. The target react...

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Synthesis and study of diols containing bisphenol fragments and of polymers produced on their basis

Cited by 15 publications

References 0 publications

New insight into the kinetics of diisocyanate‐alcohol reactions by high‐performance liquid chromatography and mass spectrometry

New insight into the kinetics of diisocyanate‐alcohol reactions by high‐performance liquid chromatography and mass spectrometry

Kinetics of Uncatalyzed Reactions of 2,4′- and 4,4′-Diphenylmethane-Diisocyanate with Primary and Secondary Alcohols

Design of High-Performance Heterogeneous Metal Catalysts for Green and Sustainable Chemistry

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