5613-46-7Relevant academic research and scientific papers
Effect of UV irradiation and physical aging on O2 and N2 transport properties of thin glassy poly(arylene ether ketone) copolymer films based on tetramethyl bisphenol A and 4,4′-difluorobenzophenone
Liu, Qiang,Shaver, Andrew T.,Chen, Yu,Miller, Gregory,Paul, Donald R.,Riffle,McGrath, James E.,Freeman, Benny D.
, p. 202 - 214 (2016)
Modification of membranes to improve gas separation properties has been of considerable interest. Crosslinking is one route to modify membranes, but such studies need to be performed on thin membranes to quantify the impact of such modifications at thicknesses relevant to industrial membranes. In this study, the influences of UV irradiation and physical aging on O2 and N2 gas permeation properties of thin (～150 nm) glassy, amorphous poly(arylene ether ketone) (PAEK) copolymer films at 35°C and 2 atm were investigated. Thin PAEK copolymer films, prepared from tetramethyl bisphenol A (TMBPA) and 4,4′-difluorobenzophenone (DFBP), were UV irradiated on both sides in air or N2 at 254 nm or 365 nm, which induced crosslinking and, in some cases, photooxidation. Gas permeability decreased and O2/N2 selectivity increased as UV irradiation and aging time increased. At 254 nm, samples irradiated in air have lower permeability coefficients and higher selectivities than samples irradiated in N2, which was ascribed to additional decreases in free volume due to photooxidation in samples irradiated in air. Additionally, samples irradiated in air at 254 nm exhibit less physical aging than uncrosslinked and samples irradiated in N2 at 254 nm, possibly due to interactions among photooxidative polar products that may restrict polymer chain mobility, thereby lowering the aging rate. The influence of water vapor on physical aging of samples irradiated in air was examined. Finally, irradiation at 254 nm leads to more extensive crosslinking and/or photooxidation than irradiation at 365 nm, possibly due to greater UV absorption by the polymer and the higher probability of radical formation at the lower wavelength.
Preparation method of tetramethyl bisphenol A
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Paragraph 0008; 0014-0033, (2021/05/15)
The invention discloses a preparation method of tetramethyl bisphenol A. The preparation method comprises the following steps: 1) mixing 2, 6-dimethylphenol, acetone, a main catalyst, an auxiliary catalyst and a mixed solvent to obtain a reaction solution, and reacting the reaction solution at 20-60 DEG C until the reaction is finished; (2) adding a hydrophobic solvent into the reaction liquid, performing heating and dissolving, separating out an oil layer, adjusting the pH value of the oil layer to be neutral, and performing washing until the conductivity is less than 50 mu S/cm; 3) cooling the oil layer treated in the step 2) to obtain tetramethyl bisphenol A crystal mush, and performing cooling, centrifuging, washing, drying and discharging to obtain tetramethyl bisphenol A; (4) treating the crystallization mother liquor in the step (3), recovering excessive and unreacted raw material 2, 6-dimethylphenol, adding a hydrophobic solvent into the remaining residues, and repeating the steps (2)-(3) to obtain the tetramethyl bisphenol A. The method disclosed by the invention is low in impurity conversion rate and high in product purity, and realizes low emission of the preparation process.
BISPHENOL COMPOSITION CONTAINING AROMATIC ALCOHOL SULFONATE AND METHOD FOR PRODUCING SAME, POLYCARBONATE RESIN AND METHOD FOR PRODUCING SAME, AND BISPHENOL PRODUCTION METHOD
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Paragraph 0288, (2020/07/07)
A bisphenol composition including a specific amount of aromatic alcohol sulfonate, and a simple method of producing it are provided. Also provided is a method of producing a polycarbonate resin in which, by using the bisphenol composition including a specific amount of aromatic alcohol sulfonate, melt polymerization reaction can be efficiently allowed to proceed to produce a polycarbonate resin having an excellent color tone. A bisphenol composition including an aromatic alcohol sulfonate at not less than 0.1 ppb by mass with respect to a bisphenol. A method of producing a bisphenol composition, including reacting a ketone or an aldehyde with an aromatic alcohol in the presence of sulfuric acid to produce a bisphenol composition. A method of producing a polycarbonate resin, including producing a polycarbonate resin using the bisphenol composition. A polycarbonate resin including a specific amount of aromatic alcohol sulfonate.
Method for producing a bisphenol, and, production of polycarbonate resin (by machine translation)
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Paragraph 0164-0165; 0168-0169, (2019/08/21)
[Problem] aromatic alcohols and ketone or aldehyde from reaction of bisphenol a, bisphenol to shorten the reaction time, produced bisphenol selectivity is improved, having good color tone bisphenol production can be obtained. [Solution] aromatic alcohols containing organic phase, the aqueous phase is separated from the oil and water containing sulfuric acid, wherein the organic phase in the aromatic alcoholic sulfone acid, aromatic alcoholic sulfone acid (1) to obtain a liquid reaction product containing, a reaction liquid containing the aromatic alcoholic sulfone acid, ketone or aldehyde mixture, the aromatic alcoholic sulfone in the presence of acid, the aromatic alcohol, wherein said step (2) produced from a ketone or aldehyde to bisphenol a, bisphenol a production. [Drawing] no (by machine translation)
Preparation method of high-purity tetramethyl bisphenol A
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Paragraph 0051-0054, (2020/01/12)
The invention discloses a preparation method of high-purity tetramethyl bisphenol A. The preparation method of the high-purity tetramethyl bisphenol A comprises the following steps: 1) in a reactor, heating 2,6-xylenol to a molten state, then adding an organic carboxylic acid catalyst, and mixing and stirring; 2) continuing to add an organic sulfonic acid catalyst, then adding acetone, and carrying out a reaction to obtain slurry; 3) transferring the slurry to a kneading machine, and stirring to obtain a paste product; and 4) transferring the paste product to a stirrer, adding an organic solvent, washing and filtering, and drying the obtained solid product. The preparation method provided by the invention can be used for obtaining high-purity and high-yield tetramethyl bisphenol A with thepurity of more than 98.5% and the yield of more than 75%, and has a wide application prospect.
METHOD OF BISPHENOL MANUFACTURE
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Paragraph 0045-0048, (2017/07/08)
An improved method of manufacture of a bisphenol comprises heating a monohydric phenol to a first temperature sufficient to melt the monohydric phenol; adding a carbonyl compound to 2.0-3.0 molar equivalents, based on the moles of carbonyl compound, of the monohydric phenol in the presence of catalytic amounts of an organosulfonic acid catalyst and a reaction promoter at a second temperature sufficient to maintain unreacted monohydric phenol in a molten state; increasing the temperature to a third temperature higher than the second temperature, and mixing for a time sufficient to produce the bisphenol in a yield of 80 to 100%, based on the amount of carbonyl compound; wherein mineral acids, Lewis acids, and ion exchange resins are not used. The method is applicable to the manufacture of 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, a useful intermediate for the manufacture of bifunctional poly(phenylene ether)s.
Aromatics to bis-triquinane: A tandem oxidative dearomatization of bis-phenol, cycloaddition, photorearrangement and a rapid entry into carbocyclic framework of Xeromphalinone e
Singh, Deepak,Chaudhari, Umesh V.,Deota, Pradeep T.
, p. 4485 - 4493 (2014/06/10)
A novel approach for the synthesis of a bird-shaped bis-triquinane 3, a fascinating carbocyclic framework closely related to the skeleton of Xeromphalinone E 1 from readily available 2,6-dimethyl phenol 8 has been reported. The synthesis of bis-cyclohexadienones 6, 22a-e by oxidative acetylation of tetramethyl bisphenols 7, 20a-e has been investigated using two different reagents under varying reaction conditions. The cycloaddition of bis-cyclohexadienone 6 gives two carbocycles, bis-adduct 4b and mono-adduct 5d in a stereocontrolled manner. The photochemical sigmatropic 1,2-acyl shift in 4b furnished 3 and monotriquinane 9 linked with a 9-acetoxy-9-methyl-endo- tricyclo[5,2,2,02,6]undeca-4,10-diene-8-one system. Two different pentasubstituted phenols 13 and 14 were also isolated during an attempted oxa-di-π-methane (ODPM) rearrangement of mono-adduct 5d via aromatisation of the cyclohexadienone ring. The photochemical behaviour of bis-cyclohexadienones 6, 22a-e has also been investigated under UV irradiation and two different aromatized products were isolated for each bis-cyclohexadienone by migration and elimination of acetate groups.
Structural optimization and biological evaluation of substituted bisphenol a derivatives as β-amyloid peptide aggregation inhibitors
Zhou, Yu,Jiang, Chunyi,Zhang, Yaping,Liang, Zhongjie,Liu, Wenfeng,Wang, Liefeng,Luo, Cheng,Zhong, Tingting,Sun, Yi,Zhao, Linxiang,Xie, Xin,Jiang, Hualiang,Zhou, Naiming,Liu, Dongxiang,Liu, Hong
experimental part, p. 5449 - 5466 (2010/11/05)
The aggregation of A? is a crucial step in the etiology of Alzheimer's disease. Our previous work showed that A? undergoes ?-helix/?-sheet intermediate structures during the conformational transition, and an A? aggregation inhibitor (1) was discovered by targeting the intermediates. Here, structure optimization toward compound 1 was performed and 34 novel derivatives were designed and synthesized. Nine compounds showed more effective inhibitory activity than the hit compound 1 in ThT fluorescence assay. Among them, compound 43 demonstrated more excellent inhibitory potency, which not only can suppress the aggregation of A? but also can dissolve the preformed fibrils as shown by CD spectroscopy, PICUP and AFM assays. Cellular assay indicated that 43 has no toxicity to neuronal cells, moreover, can effectively inhibit A? 1?42-induced neutrotoxicity and increase the cell viability. Together, on the basis of these positive results, these novel chemical structures may provide a promising potential for therapeutic applications in AD and other types of neurodegenerative disorders.
Chiral macrocyclic bis(oxazoline) Cu1 complexes - Structure/stereoselectivity relationships in catalytic cyclopropanations
Portada, Tomislav,Roje, Marin,Raza, Zlata,Caplar, Vesna,Zinic, Mladen,Sunjic, Vitomir
, p. 838 - 856 (2008/02/08)
The design and synthesis of 18 chiral macrocycles with built in C 2-symmetric bis(oxazoline) units is described and the catalytic properties of their copper(I) complexes in cyclopropanations of styrene with ethyl diazoacetate are assessed. The bridging of two homochiral centers in the bis(oxazoline) unit gives a macrocyclic ligand, which upon binding of Cu 1 is transformed into a macrocyclic catalytic complex containing a chiral cavity. Such a complex represents a conceptually new type of supramolecular organometallic catalyst, possessing a chiral reaction cavity. A clear relationship between catalyst structures and the stereoselectivity outcome in the catalytic cyclopropanations has been established and it is demonstrated that both the enantioselectivity and the diastereoselectivity can be independently modified by variation of the ligand structural parameters. The Cu1 complex of the ligand 3b gave a trans/cis diastereomeric ratio of 94:6 (de = 88%), representing the highest diastereoselectivity obtained to date for cyclopropanations catalyzed by the bis(oxazoline) class of complexes. An explanation of the observed relationship between stereochemical outcome and ligand structure is proposed. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
