Day: October 14, 2022

Xiao, Peng; He, Xiaojie; Zheng, Feng; Lu, Qinghua published the artcile< Super-heat resistant, transparent and low dielectric polyimides based on spirocyclic bisbenzoxazole diamines with Tg > 450°C>, Name: Cyclobuta[1,2-c:3,4-c’]difuran-1,3,4,6(3aH,3bH,6aH,6bH)-tetraone, the main research area is polyimide spirocyclic bisbenzoxazole diamine glass transition temperature.

Maintaining ultra-high heat resistance and sufficient colorless transparency at the same time is a challenge for polymer materials because of conflicting design principles, but such materials are urgently needed for some optoelectronic devices. In this study, four new isomeric diamines with a spirocyclic bisbenzoxazole structure were synthesized, and their polyimides were prepared by condensation with com. diamines, 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and cyclobutane-1,2,3,4-tetracarboxylic acid dianhydride (CBDA) followed by chem. imidization. The resultant polyimide (PI) films have excellent optical transparency with cut-off wavelengths in the range of 346 nm-380 nm, and 85%-90% transmittance at 550 nm. Also, these PIs possessed excellent solubility in common organic solvents, even in low-boiling-point solvents, such as chloroform, dichloromethane and THF. Most importantly, the colorless polyimides displayed a super-high glass transition temperature (Tg), high thermal stability, and favorable mech. properties, and their Tg reached 491°. The polyimides possessed low moisture absorptions of 0.52%-0.61% and low dielec. constants (Dk) of 2.32-2.93. The excellent comprehensive properties of the spirocyclic bisbenzoxazole-containing colorless transparent polyimides (CPIs) render these materials promising candidates for optical and optoelectronic applications.

Polymer Chemistry published new progress about Absorption. 4415-87-6 belongs to class tetrahydrofurans, and the molecular formula is C8H4O6, Name: Cyclobuta[1,2-c:3,4-c’]difuran-1,3,4,6(3aH,3bH,6aH,6bH)-tetraone.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Koley, Paramita; Rao, B. Srinivasa; Sabri, Ylias M.; Bhargava, Suresh K.; Tardio, James; Lingaiah, N. published the artcile< Selective conversion of furfural into tetrahydrofurfuryl alcohol using a heteropoly acid-based material as a hydrogenation catalyst>, Recommanded Product: (Tetrahydrofuran-2-yl)methanol, the main research area is vanadium palladium molybdophosphoric acid catalyst preparation furfural hydrogenation.

Tetrahydrofurfuryl alc. (THFAL) is a green solvent as well as a significant platform chem. which can be obtained from biomass derived furfural. In this study, new palladium exchanged vanadium incorporated supported heteropoly molybdate (PdMPAV2) catalysts were synthesized using a simple wet impregnation method and studied for selective hydrogenation of furfural. Six different catalysts were investigated: PdMPAV2/Al2O3, PdMPAV2/TiO2, PdMPAV2/SiO2, PdMPAV2/ZrO2, PdMPAV2/Nb2O5 and Pd/Al2O3. Of the catalysts studied the PdMPAV2/Al2O3 catalyst was able to achieve the highest selectivity of THFAL (95%) under moderate reaction conditions (150°C, 2.5 MPa, 6 h) using isopropanol as a solvent and the weight percentage of palladium is only 0.5% which is the least among all the previously reported catalysts. The other catalysts investigated achieved yields of 50-75% under the same reaction conditions. The higher selectivity obtained using the alumina supported catalyst was explained using a range of physicochem. methods: XRD, temperature programmed reduction (H2-TPR), CO pulse chemisorption, BET surface area anal. and SEM. The H2-TPR results showed that PdMPAV2/Al2O3 contained a significant amount of Pd that was reduced at the lowest temperature (~100°C) observed for all the materials investigated, which indicated that this catalyst most likely contained a significantly greater amount of more highly dispersed/higher surface area Pd than the other catalysts investigated which is also supported by CO pulse chemisorption results. XPS results supported the presence of Pd(0) which is stabilized by a heteropoly acid framework, and TEM and CO chemisorption results illuminated the fact that the well dispersed and smaller palladium cluster is one of the crucial factors for the better activity of PdMPAV2/Al2O3. The effects of the variation of temperature, pressure, time and catalyst concentration were investigated for the best performing catalyst (PdMPAV2/Al2O3).

Sustainable Energy & Fuels published new progress about Chemisorption. 97-99-4 belongs to class tetrahydrofurans, and the molecular formula is C5H10O2, Recommanded Product: (Tetrahydrofuran-2-yl)methanol.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Byun, Mi Yeon; Lee, Man Sig published the artcile< Effect of carboxylate stabilizers on the performance of Pt/C catalysts for furfural hydrogenation>, Related Products of 97-99-4, the main research area is platinum carbon furfural hydrogenation catalyst.

Highly dispersed carbon-supported Pt (Pt/C) catalysts with various carboxylate stabilizers were prepared by deposition-reduction and characterized. The Pt complexes surrounded by stabilizer retard the aggregation of Pt nanoparticles during the precipitation and reduction process. Increasing the carbon chain length of the stabilizer from one to two resulted in nanosized Pt particles, which afforded more stable nucleation and growth of the Pt. However, increasing the alkyl chain length of the stabilizer to five produced aggregated Pt particles because the particles became entangled during the interaction between the Pt complexes and the carbon support. The Pt/C catalyst prepared by using sodium succinate dibasic as the stabilizer has the highest Pt dispersion at 68%. The Pt/C catalysts with carboxylate stabilizers were evaluated for use in aqueous-phase furfural hydrogenation. Catalysts with a higher Pt dispersion exhibited higher furfural conversion and higher selectivity for furfuryl alc. Using sodium succinate as the stabilizer, the optimum conditions afforded 100% furfural conversion and 86.6% furfuryl alc. selectivity.

Journal of Environmental Chemical Engineering published new progress about Adsorption. 97-99-4 belongs to class tetrahydrofurans, and the molecular formula is C5H10O2, Related Products of 97-99-4.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Tran, Luc-Sy; Carstensen, Hans-Heinrich; Foo, Kae Ken; Lamoureux, Nathalie; Gosselin, Sylvie; Gasnot, Laurent; El-Bakali, Abderrahman; Desgroux, Pascale published the artcile< Experimental and modeling study of the high-temperature combustion chemistry of tetrahydrofurfuryl alcohol>, SDS of cas: 97-99-4, the main research area is tetrahydrofurfuryl alc high temperature combustion chem.

In the present study, the high-temperature (HT) combustion chem. of tetrahydrofurfuryl alc. (THFA), a THF based biofuel, was investigated using a comprehensive exptl. and numerical approach.Representative chem. species profiles in a stoichiometric premixed methane flame doped with ∼20% (molar) THFA at 5.3 kPa were measured using online gas chromatog. The flame temperature was obtained by NO laser-induced fluorescence (LIF) thermometry. More than 40 chem. products were identified and quantified. Many of them such as ethylene, formaldehyde, acrolein, allyl alc., 2,3-dihydrofuran, 3,4-dihydropyran, 4-pentenal, and tetrahydrofuran-2-carbaldehyde are fuel-specific decomposition products formed in rather high concentrations In the numerical part, as a complement to kinetic modeling, high-level theor. calculations were performed to identify plausible reaction pathways that lead to the observed products. A detailed kinetic model for high-temperature combustion of THFA was developed, which reasonably predicts the exptl. data. Subsequent rate anal. showed that THFA is mainly consumed by H-abstraction reactions yielding several fuel radicals that in turn undergo either β-scission reactions or intramol. radical addition that effectively leads to ring enlargement. Along THFA reaction routes, the derived species with cis configuration were found to be thermodynamically more stable than their corresponding trans configuration, which differs from usual observations for hydrocarbons.

Proceedings of the Combustion Institute published new progress about Biofuels. 97-99-4 belongs to class tetrahydrofurans, and the molecular formula is C5H10O2, SDS of cas: 97-99-4.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Yan, Houchun; Han, Yuanyuan; Sun, Shiwei; Han, Mai; Fan, Wenyang; Li, Qingsong published the artcile< Liquid-liquid equilibrium for ternary systems of water + tetrahydrofurfuryl alcohol + isopentanol/1-hexanol at 303.2, 313.2, 323.2 K>, Recommanded Product: (Tetrahydrofuran-2-yl)methanol, the main research area is water tetrahydrofurfuryl alc isopentanol hexanol liquid equilibrium.

In 101.3 kPa, Liquid-liquid equilibrium (LLE) data of water + tetrahydrofurfuryl alc. (THFA) + isopentanol/1-hexanol were measured at 303.2, 313.2, and 323.2 K. The distribution coefficient and separation coefficient of THFA extracted from water were used to assess the utility. The measured data were connected through the NRTL and UNIQUAC models to regress the binary interaction parameters. The GUI-MATLAB was used to check the consistency of the calculated binary interaction parameters and LLE data. The RMSD of both models were less than 0.0077 to prove their consistency with the exptl. data.

Journal of Chemical Thermodynamics published new progress about Liquid-liquid equilibrium. 97-99-4 belongs to class tetrahydrofurans, and the molecular formula is C5H10O2, Recommanded Product: (Tetrahydrofuran-2-yl)methanol.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Jeong, Keuk-Min; Tapaswi, Pradip Kumar; Kambara, Takehiko; Ishige, Ryohei; Ando, Shinji; Ha, Chang-Sik published the artcile< Photoconductive polyimides derived from a novel imidazole-containing diamine>, SDS of cas: 4415-87-6, the main research area is imidazole containing polyimide preparation photoconductive property.

A new diamine containing an imidazole structure, 4,4′-(4,5-diphenyl-1H-imidazole-1,2-diyl)dianiline (DIMA), was synthesized to prepare photoconductive polyimides (PIs) with four types of dianhydrides such as 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 4,4′-(hexafluoroisopropylidene) diphthalic anhydride, and cyclobutane-1,2,3,4,-tetracarboxylic dianhydride, based on the fact that the imidazole ring is a useful n-type block with high electron-donating property and good thermal stability. The imidazole-containing diamine possesses high electron-donating properties due to the lone pair electrons at nitrogen, which affords a high hole-transport property. All the PIs prepared from DIMA were amorphous due to the large side group and kink structure of the diamine, optically transparent (transmittances of 92-98% at 450 nm), and exhibited high thermal stability (10% weight loss temperatures ranged 453-558°).

High Performance Polymers published new progress about Absorption. 4415-87-6 belongs to class tetrahydrofurans, and the molecular formula is C8H4O6, SDS of cas: 4415-87-6.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Luo, Yang; Ma, Hong; Zhang, Shujing; Zheng, Daoyuan; Che, Penghua; Liu, Xin; Zhang, Meiyun; Gao, Jin; Xu, Jie published the artcile< Binding Energy as Driving Force for Controllable Reconstruction of Hydrogen Bonds with Molecular Scissors>, Application of C5H10O2, the main research area is binding energy hydrogen bond mol scissor.

Hydrogen bonds are one of the most important directional intermol. interactions and play key roles in chem. and biochem. systems, but there is still a lack of prediction and understanding of their control. Herein, hydrogen-binding energy (EHB) acted as a driving force for controllably reconstructing hydrogen bonds with mol. scissors. We related hydrogen-binding energies of the donor-acceptor couple (EHB,2) and the donor itself (EHB,1) and ΔG based on ΔG = a1EHB,1 + a2EHB,2 + a3. When EHB,1 and EHB,2 satisfy the condition ΔG < 0, the acceptor is predicted as mol. scissors with sufficient reconstruction capacity in breaking the initial hydrogen bonds and forming new ones. Remarkably, we developed an exptl. method to determine the EHB values by a linear equation as a function of chem. shifts (δ), which is innovational since in the former research EHB can only be deduced from empirical formulas and DFT calculation On that basis, the hydrogen bonds of α-cellulose were broken and re-formed in mol. scissors-consisting deep eutectic solvents, leading to the white powder transforming into a hydrogel and colorless and transparent thin film materials with distinct crystalline structure, surface flatness, and morphol. Journal of the American Chemical Society published new progress about Binding energy. 97-99-4 belongs to class tetrahydrofurans, and the molecular formula is C5H10O2, Application of C5H10O2.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Peijnenburg, W. J. G. M.; Buck, H. M. published the artcile< The effects of substituents and solvent polarity on photochemical [1,3] sigmatropic shifts. Experimental evidence in favor of the occurrence of sudden polarization in acyclic alkenes>, Name: 2,2,5,5-Tetramethyldihydrofuran-3(2H)-one, the main research area is photorearrangement ethylidenenaphthalenol mechanism.

On direct irradiation of I in various solvents, fast E-Z isomerization around the exocyclic double bond was observed This led to the formation of a 50:50 mixture of E/Z isomers. Further irradiation of this mixture resulted in the clean formation of II, the product derived from a photochem. [1,3]-OH shift in I or its geometric isomer. The yield of II decreases going from a highly apolar solvent to the most polar solvent, n-hexane-autonitrile. This result is a clear support in favor of the sudden polarization mode 1.

Tetrahedron published new progress about Photorearrangement. 5455-94-7 belongs to class tetrahydrofurans, and the molecular formula is C8H14O2, Name: 2,2,5,5-Tetramethyldihydrofuran-3(2H)-one.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Tal, Nitzan; Morehouse, Benjamin R.; Millman, Adi; Stokar-Avihail, Avigail; Avraham, Carmel; Fedorenko, Taya; Yirmiya, Erez; Herbst, Ehud; Brandis, Alexander; Mehlman, Tevie; Oppenheimer-Shaanan, Yaara; Keszei, Alexander F. A.; Shao, Sichen; Amitai, Gil; Kranzusch, Philip J.; Sorek, Rotem published the artcile< Cyclic CMP and cyclic UMP mediate bacterial immunity against phages>, Recommanded Product: ((2R,3S,4R,5R)-5-(2,4-Dioxo-3,4-dihydropyrimidin-1(2H)-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl dihydrogen phosphate, the main research area is Pycsar; anti-phage; bacteria; cCMP; cUMP; cyclase; defense; pb8; phage; pyrimidine.

The cyclic pyrimidines 3′,5′-cyclic cytidine monophosphate (cCMP) and 3′,5′-cyclic uridine monophosphate (cUMP) have been reported in multiple organisms and cell types. As opposed to the cyclic nucleotides 3′,5′-cyclic adenosine monophosphate (cAMP) and 3′,5′-cyclic guanosine monophosphate (cGMP), which are second messenger mols. with well-established regulatory roles across all domains of life, the biol. role of cyclic pyrimidines has remained unclear. Here we report that cCMP and cUMP are second messengers functioning in bacterial immunity against viruses. We discovered a family of bacterial pyrimidine cyclase enzymes that specifically synthesize cCMP and cUMP following phage infection and demonstrate that these mols. activate immune effectors that execute an antiviral response. A crystal structure of a uridylate cyclase enzyme from this family explains the mol. mechanism of selectivity for pyrimidines as cyclization substrates. Defense systems encoding pyrimidine cyclases, denoted here Pycsar (pyrimidine cyclase system for antiphage resistance), are widespread in prokaryotes. Our results assign clear biol. function to cCMP and cUMP as immunity signaling mols. in bacteria.

Cell (Cambridge, MA, United States) published new progress about 58-97-9. 58-97-9 belongs to class tetrahydrofurans, and the molecular formula is C9H13N2O9P, Recommanded Product: ((2R,3S,4R,5R)-5-(2,4-Dioxo-3,4-dihydropyrimidin-1(2H)-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl dihydrogen phosphate.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Dwivedi, Sumant; Nag, Aniruddha; Sakamoto, Shigeki; Funahashi, Yasuyoshi; Harimoto, Toyohiro; Takada, Kenji; Kaneko, Tatsuo published the artcile< High-temperature resistant water-soluble polymers derived from exotic amino acids>, Reference of 4415-87-6, the main research area is temperature resistant water soluble polyimide preparation.

High-performance water-soluble polymers have a wide range of applications from engineering materials to biomedical plastics. However, existing materials are either natural polymers that lack high thermostability or rigid synthetic polymers. Therefore, we design an amino acid-derived building block, 4,4′-diamino-α-truxillate dianion (4ATA2-), that induces water solubility in high-performance polymers. Polyimides containing 4ATA2- units are intrinsically water-soluble and are processed into films cast from an aqueous solution The resulting polyimide films exhibit exceptional transparency and extremely high thermal stability. In addition, the films can be made insoluble in water by simple post-treatment using weak acid or multivalent metal ions such as calcium. The synthesized polyimide’s derived from bio-based resources are useful for yielding waterborne polymeric high-performance applications.

RSC Advances published new progress about Elongation at break. 4415-87-6 belongs to class tetrahydrofurans, and the molecular formula is C8H4O6, Reference of 4415-87-6.

Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem