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The adsorption of sulfur-containing compounds from fuels on polymer nanocomposite adsorbents modified with carbon-based materials was investigated. This work reports the removal of benzothiophene from the model liquid fuel using a novel adsorbent prepared by nanopoly (4,4′-methylenedianiline)-graphene oxide (NPMDA/GO) composite. The adsorbent was successfully synthesized with the in situ electrochemical method and characterized using thermal gravimetric analysis (TGA), field-scattering scanning electron microscopy (FE-SEM), transient electron microscopy (TEM), X-ray diffraction analysis (XRD), and Fourier transform infrared (FTIR). The results showed that the presence of graphene oxide (GO) nanosheets in NPMDA/GO composite adsorbent due to its high tendency to sulfur would increase the adsorption of benzothiophene compared to unmodified nanopoly (4,4′-methylenedianiline) (NPMDA). The π_complexation, oxygenated organic functional groups, and layered sheets of graphene oxide improve adsorption capacity for desulfurization. The NPMDA/GO composite presented maximum efficiency (63.33%) at 30 mg/L initial concentration, 120 mg adsorbent dose, and 120 min contact time at 25 °C. Furthermore, the adsorbent shows an almost good reusability after four cycles (67.12 mg/g sulfur absorption capacity). Pseudo-second-order model ( R 2  = 0.9975) and the Freundlich isotherm ( R 2  = 0.8813) were used to describe the adsorption process. Findings confirm that NPMDA/GO composite can be applicable for removal of benzothiophene from liquid fuels.

Aromatic N-heterocyclic compounds are very important chemicals, which are currently produced mostly from petroleum. Here we report that a pyridazine-based compound 6-(4-hydroxy-3-methoxyphenyl)pyridazin-3(2H)-one (GSPZ) can be efficiently synthesized by the Friedel-Crafts reaction of guaiacol and succinic anhydride, both of which can be derived from biomass. GSPZ is then treated with bio-based epichlorohydrin to prepare the epoxy resin precursor GSPZ-EP. With 4,4'-diaminodiphenylmethane as curing agent, GSPZ-EP possesses higher glass transition temperature (187  o C vs. 173  o C) and shows a 140%, 70 and 93% increase in char yield (in N 2 ), storage modulus (30  o C) and Young’s modulus, respectively when compared with a standard petroleum-based bisphenol A epoxy resin. Moreover, the cured GSPZ-EP shows good intrinsic flame retardancy properties and is very close to the V-0 rating of UL-94 test. This work opens the door for production of aromatic N-heterocyclic compounds, which can be derived from biomass and employed to construct high performance polymers. Aromatic N-heterocyclic compounds are important chemicals, but produced from petroleum. Here the authors show a pyridazine-based compound 6-(4-hydroxy-3-methoxyphenyl)pyridazin-3(2H)-one, used as polymer feedstocks, can be synthesized by a Friedel-Crafts reaction from biomass starting materials.

Epoxy resins with a high dielectric constant and low intrinsic thermal conductivity coefficient cannot meet the current application requirements of advanced electronic and electrical equipment. Therefore, novel fluorine‐containing liquid crystal epoxy compounds (TFSAEy) with fluorinated groups, biphenyl units, and flexible alkyl chains are first synthesized via amidation and esterification reactions. Then, 4,4′‐diaminodiphenylmethane (DDM) is used as a curing agent to prepare the corresponding fluorine‐containing liquid crystal epoxy resins. The obtained dielectric constant (ε) and dielectric loss (tan δ) values of TFSAEy/DDM at 1 MHz are 2.54 and 0.025, respectively, which are significantly lower than those of conventional epoxy resins (E‐51/DDM, 3.52 and 0.038). Additionally, the intrinsic thermal conductivity coefficient (λ) of TFSAEy/DDM is 0.36 W/(m·K), 71.4% higher than that of E‐51/DDM (0.21 W/(m·K)). Meanwhile, the corresponding elastic modulus, hardness, glass transition temperature, and heat resistance index of TFSAEy/DDM are 5.73 GPa, 0.35 GPa, 213.5°C, and 188.7°C, respectively, all superior to those of E‐51/DDM (3.68 GPa, 0.27 GPa, 107.2°C, and 174.8°C), presenting potential application in high‐heating electronic component packaging and printed circuit boards. A novel fluorine‐containing liquid crystal epoxy cured resins (TFSAEy/DDM) have the optimal comprehensive properties, such as a low ε value, highly intrinsic λ value, excellent mechanical properties, outstanding heat resistance, wear resistance and flame retardancy, which would replace conventional epoxy resins (E‐51/DDM) in the high‐heating electronic component packaging and printed circuit boards.

Internal insulation of high‐voltage power modules is facing interesting failure risks, including high temperature overheating, breakdown fault, material cracking etc., so it is imperative to urgently develop new dielectric materials with high thermal conductivity (λ), outstanding electrical insulation, and thermal stability properties. A method to construct controllable liquid crystalline cross‐linking networks based on the synthesis of biphenyl epoxy monomer and the change of curing agent structures and curing temperature is proposed. The uniform nematic rod‐like liquid crystalline domains were obtained by using 4,4‐diaminodiphenylmethane as a curing agent under a pre‐curing temperature of 105°C. The resulting film (abbreviated as TD‐105) exhibited λ up to 0.53 W m−1 K−1 and a dielectric breakdown strength of 57.69 kV mm−1, which showed a simultaneous enhancement of 178% and 16%, respectively, compared to traditional bisphenol A epoxy resin. Moreover, it also exhibited lower dielectric loss and magnitude of partial discharge while having higher glass‐transition temperature (190°C). A novel idea for the development of high‐performance epoxy insulating materials for the application of high‐voltage and large‐power electrical equipment is provided.

Through differential scanning calorimeter (DSC), the systematic analysis is carried out on the issues including: the curing properties of the resin system composed of 4,4’-diaminodiphenylmethane epoxy resin (AG-80), 4,4’-diaminodiphenylsulfone (DDS) and boron trifluoride monoethylamine complex (BF 3 -MEA); the effect imposed by the varying content of BF 3 -MEA on the temperature, extent and rate of reaction; and the effect imposed by the varying DSC heating rates on the curing properties of the AG-80/DDS/BF 3 -MEA resin system. In the meantime, Ti 0 , Tp 0 and Tf 0 are derived, and the curing regimes of the three proportioning schemes are determined accordingly. The gel time of the AG-80/DDS/BF 3 -MEA resin system is measured through the gel drawing method, and the effect of the BF 3 -MEA content on the gel time is assessed, so as to determine that 0.7 times of the gel time shall be the pressure time for the forming of composite materials. Furthermore, tests are carried out on the mechanical properties of the resin cast and the carbon fiber composite materials prepared through the three proportioning schemes. The results have shown that when the content of BF 3 -MEA is 2%, the AG-80/DDS/BF 3 -MEA resin system outperforms the other proportioning schemes in terms of the curing process and the processability of its composite materials. Besides, the comprehensive mechanical properties of the resin cast and the carbon fiber composite are better.

The zirconium ethylenediamine tetramethylene phosphonate (ZrEDTMPS) proton conductor with –PO 3 H 2 groups which can easily form hydrogen bonds and encourage proton transfer in low RH is synthesized and doped into the PBI-based membranes. The epoxy groups of tetrafunctional N, N, N’, N’-tetraglycidy-4,4'-diaminodiphenylmethane (TGDDM) react with the NH groups in polybenzimidazole (PBI) and form a cross-linking network structure to improve the mechanical properties, oxidative stability and dimensional stability of the composite membranes. At 180 °C, the proton conductivity of the mPBI-TGDDM (10%)/ZrEDTMPS (30%) is 0.122, 0.050, and 0.029 S cm −1 at 100%, 50%, and 0 RH, respectively. Meanwhile, the mPBI-TGDDM/ZrEDTMPS membranes exhibit high oxidative stability (the mass loss of membranes is 2.1%). Compared with Nafion 117 (5.5 × 10 −7  cm 2  s −1 ), the methanol permeability of mPBI- TGDDM/ZrEDTMPS membrane at 70 °C (6.38 × 10 –8  cm 2  s −1 ) is one order of magnitude lower. The mPBI-TGDDM/ZrEDTMPS membranes have good comprehensive performance and can be used in proton exchange membrane fuel cells. Graphical abstract

A bio-based epoxy resin, triglycidyl ether of resveratrol (TGER), was synthesized based on the renewable resveratrol deriving from tannins. The structure and properties of TGER have been characterized by 1 H NMR, 13 C NMR, FTIR, GPC and viscosity measurement. Besides, systematical investigation was carried out on the curing reaction of TGER and diaminodiphenylmethane (DDM), assisted by the characterization of mechanical properties and thermal properties of cured TGER/DDM by means of differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis (DMA), flexural and impact measurement. Non-isothermal and isothermal curing analysis showed that TGER/DDM system, deriving from autocatalytic curing reaction, possessed 40 °C lower curing temperature (84 °C) than bisphenol A diglycidyl ether (DGEBA) (124 °C) and much lower activation energy than DGEBA/DDM system calculated by Kissinger equation. DMA revealed that TGER possessed high glass transition temperature ( T g  = 148 °C) and glassy storage modulus (2.391 GPa@23 °C). Meanwhile, TGER/DDM thermosets also exhibited good mechanical properties and heat resistance, illustrating that multi-phenol group and stilbene group of resveratrol endowed polymer with high cross-linking density and rigidness. Therefore, TGER could be a promising alternative to petroleum-based epoxy resin.

Heat conductive epoxy composites as electronic packaging materials present wider applications. However, the high loading of fillers required for a high thermal conductivity ( k ) inevitably degrades the electrical resistivity and breakdown strength ( E b ) of epoxy composites, significantly limiting their urgent applications in high voltage fields. The key to tackling this dilemma is to improve the intrinsic k of pristine epoxy with inherently disordered structure. Liquid crystal epoxy (LCE) containing rod-shaped mesogenic units and flexible segments, emerges as a unique epoxy resin presenting inherently high- k realized via self-assembling the mesogens into ordered domains, represents a promising solution to this critical issue. In this work, two types of LCEs, i.e., BE and LCM6, were designed and synthesized, and their LC behaviors were investigated. Further, the thermal and electric properties of the 4,4-methylenedianiline cured BE/LCM6 were explored as a function of the LCM6 loading. The results reveal that the cured BE/LCM6 at an optimal ratio showcases the obviously elevated k and E b along with low dielectric permittivity and loss, when compared with traditional epoxy and a single LCE component. The concurrent enhancement in both k and E b is ascribed to the introduced ordered domains resulting from the self-assembled mesogens into the cured epoxy network, which pave the highway for phonon transport and impede the migration of charge carries. The prepared LCEs with high k and E b show appealing application prospects in electrical power systems.

Developing cross-linked polymers with both low dielectric constant and degradability for microelectronics and sustainability remains a challenge. Herein, a new fluoro-containing dialdehyde monomer (VF) derived from vanillin was synthesized, which was then cross-linked with a tris (2-aminoethyl) amine (TREN) and different diamines (4, 4 ′ -methylenebis (cyclohexylamine) (PACM), 4, 4 ′ -diaminodiphenylmethane (DDM) and 1, 6-hexamethylenediamine (HMDA)) to give three polyimines thermosets, namely VFT-P, VFT-D and VTF-H, respectively, showing controlled comprehensive properties through regulation of imine cross-linked structures. Properties-function relationship of these polyimines was systematically studied and focused mainly on revealing the degradation process and the mechanism of the degradability of polyimines. The results indicated that among these polyimines, VFT-P exhibited superior conventional properties and acid resistance due to its appropriate reactivity, cross-linked density, rigid non-conjugated Schiff base structures, and high free volume. The storage modulus, glass transition temperature, transmittance, and tensile strength of VFT-P polyimines could reach 3.40 GPa, 134 °C,  > 97% (at 500–800 nm) and 62.47 ± 3.65 MPa, respectively. Besides, a low dielectric constant of 2.96 at 100 MHz and superior degradability was achieved. This study introduces a facile and effective design strategy to achieve the compatibility of target properties and also offers a potentially sustainable alternative to conventional cross-linked dielectric polymers. Graphical abstract

A potential link has been reported between skin exposure to aromatic amines, such as ortho-toluidine (OT) and 3,3′-dichloro-4,4′-diaminodiphenylmethane (MOCA), and bladder cancer cases observed in Japanese chemical factories. To evaluate this association, we explored the permeability of OT and MOCA through pig skin and investigated the subsequent changes in plasma and urine concentrations in rats following percutaneous exposure. Employing Yucatan micropig skin, we first executed a permeability test by affixing the skin to a diffusion cell and applying 14 C-labeled OT or MOCA. The receptor fluid’s radioactivity was quantified at intervals of 1, 3, 6, 8, 24, and 48 h after application using a liquid scintillation counter. Next, we applied lint cloths drenched in OT and MOCA solutions to the backs of 7-week-old male F344 rats and monitored plasma and urine concentrations over time. Additionally, we investigated the pharmacokinetics of 14 C-labeled OT or MOCA solutions for 8 h following percutaneous administration. Both OT and MOCA demonstrated high skin penetration; in particular, plasma concentrations significantly rose at 6 h for OT and 8 h for MOCA after exposure. However, OT was rapidly absorbed into the bloodstream and swiftly excreted into the urine, indicating quick absorbability. In contrast, MOCA penetrated the skin quickly but exhibited delayed bloodstream entry and urinary excretion, suggesting slower absorbability. Pharmacokinetic findings revealed the rapid urinary excretion of OT, whereas MOCA was excreted in the urine and potentially in the feces as well via bile. These findings indicate that implementing measures based on chemical absorbability could significantly enhance the management of industrial chemicals where percutaneous absorbability is a concern.