Glycol Diglycidyl Research Articles

Lignin-Based Hydrogels for the Delivery of Bioactive Chaga Mushroom Extract.

Lignin-poly(ethylene)glycol diglycidyl ether hydrogels were synthesized from lignin fractions readily extracted during the hot-water treatment of angiosperms: hardwoods, sugar maple and energy-crop willow, monocotyledons, grasses, miscanthus and agriculture residues, and wheat straw. These lignins represent a broad range of chemical structures and properties as a comparative analysis of their suitability to produce the hydrogels as a novel carrier of chaga-silver nanoparticles. The formation of hydrogels was assessed via attenuated total reflectance Fourier-transformed infrared spectroscopy. Then, the hydrogels were observed via scanning electron microscopy and evaluated for their free-absorbency capacity and moduli of compression. Furthermore, a hydrogel produced from kraft lignin and two commercial hydrogels was evaluated to benchmark the effectiveness of our hydrogels. Chaga extracts were prepared via the hot-water extraction of chaga mushroom, a method selected for its relatively higher yields and preserved antioxidizing activities. Hydrogels synthesized with lignins of monocotyledons, wheat straw, and miscanthus were found to be suitable carriers for chaga-silver nanoparticles due to their favorable absorption and release behaviors.

Improved adhesion of rubber composites by developing environmentally friendly fiber impregnation coatings with good interfacial modulus transition gradients

Polyester (PET) fibers must undergo impregnation with a resorcinol-formaldehyde-latex (RFL) solution to ensure efficient adhesion with rubber. However, the harmful, carcinogenic resorcinol-formaldehyde (RF) resin in RFL impregnation solution negatively affects human health. In this paper, PET was pretreated with blocked isocyanate and epoxy resins to activate the fibers, and a new environmentally friendly fiber impregnation coating was developed. In the new impregnation coatings, ethylene glycol diglycidyl ether (EGDE) and m-xylylenediamine (MXDA) were applied to replace the resorcinol and formaldehyde. Moreover, glycidyl methacrylate (GMA) containing epoxy groups and double bonds was introduced to enhance interaction with rubber further, and then styrene-butadiene-vinyl-pyridine (VP) latex was mixed. The results show that the peel strength of the impregnated PET/rubber composites with the new impregnation coatings can reach 14.0 N/mm, representing an increase of 30.8 % compared to that of the sample with the pure RFL impregnation coatings, whose peel strength is only 10.7 N/mm. Furthermore, the mechanism for enhancing the interfacial adhesive properties of PET/rubber composites was performed by analyzing the chemical composition and morphological changes of the impregnated PET surface, as well as the change of sulfur content at the interface of the impregnated PET/rubber composites and the transition gradient of interfacial modulus.

Enabling 4.5 V Solid Polymer Batteries through a 10 µm, Crosslinked Polyether Electrolyte

AbstractThe implementation of solid polymer electrolytes (SPEs) in energy‐dense batteries faces severe challenges including sluggish ionic diffusion, oxidation tendency at the cathode interface, dendrite protrusion from the metallic anode, as well as the technological incompatibility with the layer stack‐up cell assembly. Herein, an in‐situ polymerization strategy is presented to deal with above dilemma for the solid battery prototyping. The in situ cross‐linked poly(ethylene glycol) diglycidyl ether is embedded within the nanocellulose framework, endowing SPE membrane with the reinforced mechanical strength (11.31 MPa) at the thickness of 10 µm as well as superior ionic conductance (150 mS). After a rigorous selection, the sacrificial triphenylphosphine additive preferentially oxidizes on the LiNi0.8Mn0.1Co0.1O2 (NCM811) cathode to form the cathode electrolyte interface during the formation charging. Concurrently, the solvated zinc(II) bis(trifluoromethylsulfonyl)imide constructs the polyether/LiZn mosaic layer on the Li foil, which effectively promotes interfacial cation diffusion and horizontal deposits propagation. By pairing the polymerized SPE with the thin‐layer Li foil (50 µm) and the NCM811 cathode (25 mg cm−2), the 94 mAh pouch‐format cell can realize a gravimetric/volumetric energy density of 397.5 Wh kg−1 and 1197.6 Wh L−1, high‐voltage tolerance till 4.5 V, and robust cyclability (95.1% capacity retention for 200 cycles).

Probing the influence of crosslinkers on the properties, response, and degradation of enzymatic hydrogels for electrochemical glucose biosensing through fluorescence analysis.

Drop-cast crosslinked hydrogels are a common platform for enzymatic electrochemical biosensors. Despite the widespread use of these complex systems, there are still several questions about how their physicochemical properties affect their performance, stability, and reproducibility. In this work, first-generation faradaic biosensors composed of glucose oxidase and branched polyethyleneimine (BPEI) are prepared using either glutaraldehyde (GA) or ethylene glycol diglycidyl ether (EGDGE) as crosslinkers. While EGDGE gels present an increasing electrochemical response with increasing crosslinker concentration, the current of GA gels decreases at high crosslinker concentration probably due to the hampered diffusion on tightly networked gels. We compared different strategies to use fluorescence microscopy to gain insight into the gel structure either by labeling the gel components with fluorophores or taking advantage of the intrinsic fluorescence of the imines formed upon crosslinking with GA. By monitoring the fluorescence of the crosslinking bonds and the electrochemical response, we demonstrate that hydrolysis, a common hydrogel degradation mechanism, is not responsible for the loss of electrical current over time in gels prepared with glutaraldehyde. Most hydrogel-based electrochemical biosensor studies do not perform specific experiments to determine the cause of the degradation and instead just infer it from the dependence of the current on the preparation conditions (most commonly concentrations). We show that, by taking advantage of several analytical techniques, it is possible to gain more knowledge about the degradation mechanisms and design better enzymatic biosensors.

Design of remoldable, shape-memory, welded biomass composites based on the acetal bond of the cellulose chain

The growing environmental concern over petrochemical-based plastics continuously promotes the exploration of green and sustainable biomass-based covalent adaptable networks composites (CANs). Compared with petrochemical products, cellulose and its derivatives have overwhelming superiority in terms of availability, cost and biodegradability; nevertheless, CANs using the abundant acetal bonds in the cellulose chain rather than elaborately designing other types of dynamic covalent bonds still have not received sufficient attention. Herein, we report acetal-based cellulose covalent adaptable networks (ACC) synthesized with poly(ethylene glycol) diglycidyl ether as the crosslinker for hydroxypropyl cellulose and tetrabutylammonium bromide (TBAB) as an accelerant. For the first time, exchangeability of the cellulose chain acetal reversible bonds at elevated temperature have been demonstrated to endow ACC reprocessability, shape memory and welding. The TBAB has been used as an accelerant of dynamic exchange for acetal bonds first and its accelerating mechanism and advantages have also been investigated. In addition, the thermal, mechanical and hydrophilic properties of ACC can be adjusted by simply adjusting the raw material ratio and the ACC has excellent chemical and biodegradability. Hence, ACC will provide new ideas for solving white pollution and building new CANs.

‘Green’ fabrication of PVC ultrafiltration membranes with high-flux and improved hydrophilicity by in-situ interpenetration of hydrophilic crosslinking networks

High-flux polyvinyl chloride (PVC) membranes with hydrophilic interpenetrating networks were fabricated by a ‘green’ (without toxic initiator) in-situ method in this study. The interpenetration between the polyvinyl chloride (PVC) molecules and the hydrophilic network was formed during the phase separation process, where the cross-linking was initialized by water in a solidification bath between siloxanes in aminopropyltrimethoxysilane-b-poly (ethylene glycol) diglycidyl ether synthesized in the PVC dissolution process. From the reconstruction of the PVC membrane, high hydrophilicity and porosity, and narrow pore size distribution have been achieved. As results, compared to the pristine membrane. the pure water flux was increased 17 times to 1177.4 L m−2 h−1, the flux recovery rate was increased by 15.9 %, and the strength was also increased slightly.

High capillary effect and solar dual-drive nanofibrillated cellulose aerogels for efficient crude oil spill cleanup

Frequent oil spills pose a serious threat to ecosystems, and rapid cleanup and recycling of oil spills are in high demand. Herein, inspired by natural wood structures and solar-driven viscosity-break, we developed a rapid oil-adsorption aerogel named D-CuS@CP-PMTS, which is dual-driven by capillary effect and solar energy. Briefly, copper sulfide (CuS) nanoparticles were rapidly in situ deposited on the template of oxidized nanofibrillated cellulose (ONC), aiming at achieving high photothermal effects. Subsequently, ethylene glycol diglycidyl ether (EGDE) was introduced to build multiple cross-links between CuS@ONC and polyvinyl alcohol (PVA), followed by fabricating an aerogel with directional channels for rapid oil transport using unidirectional freeze-drying technology. Finally, methyltrichlorosilane (MTS) was uniformly deposited on the aerogel using a gas–solid reaction to improve its hydrophobicity. The resulting composite aerogel achieved rapid oil adsorption with the dual assistance of solar self-heating and oriented channel structure, which significantly shortened the oil adsorption time (from 45 min to 2 min), companying with encouraging antibacterial effects. Meanwhile, rapid and repeated multiple adsorptions of high-viscosity crude oils and high melting point oils were achieved, which is superior to other reports. This work provides a new insight into adsorption and recycling of high-viscosity crude oil, and also broadens the potential application prospects of ONC-based aerogels.

Ultrasound-Triggered Amoxicillin Release from Chitosan/Ethylene Glycol Diglycidyl Ether/Amoxicillin Hydrogels Having a Covalently Bonded Network.

An antibiotic release system triggered by ultrasound (US) was investigated using chitosan (CS)/ethylene glycol diglycidyl ether (EGDE) hydrogel carriers with amoxicillin (Amox) drug. Different CS concentrations of 1.5, 2, 2.5, and 3 wt % were gelled with EGDE and Amox was entrapped in the hydrogel carrier; the accelerated release was observed as triggered by 43 kHz US exposure at different US output powers ranging from 0 to 35 W. Among these CS hydrogel systems, the degree of accelerated Amox release depended on the CS concentration for the hydrogelation and the matrix with 2 wt % CS exhibited efficient Amox release at 35 W US power with around 19 μg/mL. The drug released with time was fitted with Higuchi and Korsmeyer-Peppas models, and the enhancement was caused by US aiding drug diffusion within the hydrogel matrix by a non-Fickian diffusion mechanism. The US effect on the viscoelasticity of the hydrogel matrix indicated that the matrix became somewhat softened by the US exposure to the dense hydrogels for 2.5 and 3% CS/EGDE, while the degree of softening was slightly marked in the CS/EGDE hydrogels prepared with 1.5 and 2% CS concentration. Such US softening also aided drug diffusion within the hydrogel matrix, suggesting an enhanced Amox release.

Highly elastic photothermal nanofibrillated cellulose aerogels for solar-assisted efficient cleanup of viscous oil spill

Frequent oil spills and illegal industrial pollutant discharge cause ecological and resource damages, so it is necessary to establish efficient adsorption and recovery strategies for oils in wastewater. Herein, inspired by solar-driven viscosity-breaking, we propose a facile approach to fabricate multifunctional nanofibrillated cellulose-based aerogel with high elasticity, excellent photothermal conversion, efficient selective oil adsorption and antibacterial properties. Firstly, copper sulfide (CuS) nanoparticles were in situ deposited on the template of oxidative nanofibrillated cellulose (ONC), aiming at achieving efficient photothermal effect and antibacterial properties. Ethylene glycol diglycidyl ether (EGDE) was employed to establish multiple crosslinking network between CuS@ONC and polyethyleneimine (PEI). A thin hydrophobic PMTS layer deposited on the surface of aerogel via a facile gas-solid reaction ensured stable oil selectivity. The resulting composite aerogel can rapidly adsorb oil under solar self-heating, significantly reducing the adsorption time from 25 to 5 min. Furthermore, it exhibits excellent adsorption capacities for various oils, retaining over 92 % of its initial capacity even after 20 adsorption-desorption cycles, and the antibacterial properties extend its lifespan. This work offers a promising method for constructing multifunctional aerogels for efficient oil-water separation, especially beneficial for high-viscosity and high-melting-point oil cleanup.

Ductile, High-Lignin-Content Thermoset Films and Coatings.

In the context of transitioning toward a more sustainable use of natural resources, the application of lignin to substitute commonly utilized petroleum-based plastics can play a key role. Although lignin is highly available at low cost and presents interesting properties, such as antioxidant and UV barrier activities, its application is limited by its low reactivity, which is a consequence of harsh conditions normally used to extract lignin from biomass. In this work, the use of glyoxylic acid lignin (GA lignin), rich in carboxylic acid groups and hence highly reactive toward epoxy cross-linkers, is presented. GA lignin, which is directly extracted from biomass via a one-step aldehyde-assisted fractionation process, allowed the preparation of thermoset films and coatings via a simple reaction with sustainable poly(ethylene glycol) diglycidyl ether and glycerol diglycidyl ether cross-linkers. This allows one to prepare freestanding films containing up to 70 wt % lignin with tunable mechanical properties and covalently surface-attached coatings containing up to 90 wt % lignin with high solvent resistance. Both films and coatings display antioxidant properties and combine excellent UV barrier activity with high visible transparency, which is attractive for applications in sustainable food packaging.

Coupling fermentation of glutamic acid and γ-polyglutamic acid and preparation of poly(amino acid) superabsorbent polymers

γ-polyglutamic acid (γ-PGA) is a biomarker that can be directly obtained by microbial fermentation. Poly(amino acid) superabsorbent polymers (SAPs) were prepared with purified γ-PGA as raw material and ethylene glycol diglycidyl ether (EGDGE) as a cross-linking agent. However, γ-PGA fermentation broth has a high viscosity, requires complex extraction and separation processes, and entails high energy consumption, resulting in the high cost of poly (amino acid) SAPs. Therefore, the coupling fermentation processes of glutamate polyglutamic acid, the process of using glutamate fermentation broth instead of pure glutamate powder for fermentation, and the process of treating the fermentation broth under conditions of centrifugation, UV irradiation, and high temperature, were studied. The results showed that the yield of γ-PGA after centrifugation decreased by 5%, but it did not affect the synthesis of hydrogels, and the addition of γ-PGA fermentation broth had a significant effect on the performance of γ-PGA-co-PASP SAPs. The proposed method not only helps avoid the separation of complex γ-PGA fermentation broth and reduces the cost, but it also helps improve the performance of the super-absorbent resin, which has great application potential.

Sponge-like polyethyleneimine adsorbents with interconnected open channels enabling ultra-high CO2 adsorption and separation capacity

A novel solid amine adsorbent with interconnect open-cell porous structure was successfully synthesized by crosslinking polyethyleneimine (PEI) with ethylene glycol diglycidyl ether (EGDE) via high internal phase emulsion (HIPE) polymerization. The preparation conditions were optimized. The adsorption performance of the prepared adsorbent for CO2 was evaluated by fixed bed dynamic adsorption experiment. The results indicated that the optimal adsorbent PEI70K-E-HIPE-8 exhibited a record high CO2 adsorption capacity of 14.22 mmol/g, amine efficiency of 83% and ratio of breakthrough capacity to equilibrium capacity of 0.92 (abbreviated as Qb/Qe ratio). Both adsorption capacity and adsorption kinetics are much better than those of PEI70K-E-gel-8 prepared without using HIPE template. The adsorbent also showed good CO2/CH4 separation performance, a CH4 productivity of 54.84 mmol/g could be obtained while using PEI70K-E-HIPE-8 to separated it from a 20 mL CO2/CH4 (20:80, v:v) mixed gas, remarkably higher than that of PEI70K-E-gel-8 (0.28 mmol/g). PEI70K-E-HIPE-8 could keep a stable adsorption and separation performance after at lease 15 adsorption-desorption cycles. The superior CO2 adsorption capacity and adsorption kinetics make it a promising candidate in practical CO2 adsorption and CO2/CH4 separation application.

Accelerated ion transportation in liquid crystalline polymer networks for superior solid-state lithium metal batteries

The application of solid polymer electrolyte in high energy density lithium metal batteries is limited by low Li+ mobility, low ionic conductivity and poor cycle stability at room temperature. In the study, the free-standing flexible polymeric electrolytes (PCREs) with semi-interpenetrating-network in the topological nanostructures were fabricated through the in-situ UV-photopolymerization of the liquid crystalline monomers and poly(ethylene glycol) diglycidyl ether. Remarkably, by optimizing the relative proportion of the two liquid crystalline monomers with different methylene chains as connected bridge band between rigid center and terminal acrylate functional groups, the electrochemical properties of the prepared PCREs were successfully improved, which might contributed to the suitable ion transport channels in the porous polymer network structures. The prepared PCRE exhibited increased ion migration number, excellent ionic conductivity and a wide electrochemical window. Through the calculation of density functional theory and molecular dynamics simulation, the difference in the molecular orbital of liquid crystalline polymers and the mechanism of PCREs enhancement tLi+ were well understood. The study may provide new perspectives for the design and fabrication of high-performance polymer electrolyte materials, which will promote the development and practical application of the all-solid lithium metal batteries.

Development of PLA/Lignin Bio-Composites Compatibilized by Ethylene Glycol Diglycidyl Ether and Poly (ethylene glycol) Diglycidyl Ether.

Poly (lactic acid) (PLA) is a promising green substitute for conventional petroleum-based plastics in a variety of applications. However, the wide application of PLA is still limited by its disadvantages, such as slow crystallization rate, inadequate gas barrier, thermal degradation, etc. In this study, lignin (1, 3, 5 PHR) was incorporated into PLA to improve the thermal, mechanical, and barrier properties of PLA. Two low-viscosity epoxy resins, ethylene glycol diglycidyl ether (EGDE) and poly (ethylene glycol) diglycidyl ether (PEGDE), were used as compatibilizers to enhance the performance of the composites. The addition of lignin improved the onset degradation temperature of PLA by up to 15 °C, increased PLA crystallinity, improved PLA tensile strength by approximately 15%, and improved PLA oxygen barrier by up to 58.3%. The addition of EGDE and PEGDE both decreased the glass transition, crystallization, and melting temperatures of the PLA/lignin composites, suggesting their compatabilizing and plasticizing effects, which contributed to improved oxygen barrier properties of the PLA/lignin composites. The developed PLA/lignin composites with improved thermal, mechanical, and gas barrier properties can potentially be used for green packaging applications.

Properties of Cross‐Linked Poly‐l‐lysine Hydrogels across the Random Coil–Helix Transition

AbstractHydrogels are key components of biological tissues and have applications in biomedicine and commercial industry. Many biological tissues are known to strain harden due to the semiflexible nature of the chains. Here, the mechancial properties of poly‐l‐lysine (PLL) hydrogels, whose network chains undergo a random coil–helix transition, are studied as a function of the polypeptide's structural changes. PLL is cross‐linked with poly(ethylene glycol)diglycidyl ether at cross‐link percents ranging from 3% to 6%. The conformation change and mechanical properties are investigated with circular dichroism and small and large amplitude oscillatory shear rheology, respectively. As a function of pH at low cross‐link percents, a transition from strain softening to strain hardening is observed as the network chains become helical that is similar to the behavior of biological filamentous gels and consistent with recent theoretical descriptions of network strain hardening. At higher cross‐link densities, the hydrogels become brittle due to stress concentration in inhomogeneous locations in the network, which is studied with dynamic light scattering. Overall, the random coil–helix transition has a significant effect on the nonlinear mechanical properties of PLL hydrogels. By understanding the hydrogel structure and response to environmental changes, their potential can be expanded as functional biomedical materials.

Leveraging Microgels Prepared from Poly(ethylene glycol) Bisepoxide and Polyetheramine for Versatile Surface Structuring of Agarose Hydrogels.

We demonstrate a macromer-type bisepoxide, poly(ethylene glycol) diglycidyl ether, polymerizing readily with a trifunctional polyetheramine Jeffamine T-403 in water to facilitate the development of a series of microgels abbreviated as PMG. Simply by varying the concentration of the as-prepared thermoresponsive intermediate prepolymer from 1 to 2 and 4%, hydrodynamic sizes of the resulting P1MG, P2MG, and P4MG are easily tuned in the submicrometer to micrometer range shown by the dynamic light scattering results. Besides size difference, these microgels also deform differently, where the drying-induced deformation effect is most severe for P1MG and least prominent for P4MG. Simple evaporative deposition of PMG into multilayer packing provides versatile and green options for microgel-mediated surface structuring of agarose hydrogels. Specifically, deformabile P1MG- and P2MG-derived coatings render agarose gel microwrinkle textures by buckling against swelling-induced surface instability. Conversely, stiffer P4MG microgels lead to a patchy patterned hierarchical coating on agarose, similar to the cracking effect in drying colloidal films. The straightforward microgel-on-macrogel strategy allows integration of both wrinkle and patchy patterns to generate Janus-type agarose gels, just by rationally arranging the coating sequence. Diversifying topographic features attainable through microgel-based coatings on hydrogels could potentially make the sustainable and biocompatible material of agarose a more compelling choice for bioapplications. Brief demonstrations of the broad applicability of P1MG toward wrinkling of proteinaceous and synthetic hydrogels further highlight promising prospects of the PMG microgel-on-macrogel functionalization strategy.

Gelatin-based hydrogel with antiseptic properties: synthesis and properties

The work presents the results of research on the formation of a hydrogel polymer matrix during the gelatin crosslinking with a dioxirane derivative of poly(ethylene glycol) and experiments on studying their properties. The crosslinking process of type A gelatin using poly(ethylene glycol) diglycidyl ether (PEGDE 500) was optimized by changing the gelatin: PEGDE ratio without using any other factors. The properties of the obtained hydrogels were studied, in particular the gel fraction amount, the degree of swelling in different media, mechanical properties, pore size, cytotoxicity, the ability to absorb and release antiseptic drugs, and bactericidal properties of hydrogel samples filled with an antiseptic agent (chlorhexidine). The crosslinking reaction has been found to be the most efficient at gelatin: PEGDE 500 ratio ranging from 1:3 to 1:5. In this case, the formation of highly elastic hydrogels with maximum fraction amount and high mechanical properties was observed (the samples were not destroyed under compression). Moreover, only within this ratio range, the obtained hydrogels retained their shape when heated to 40 °C. The pore sizes of the swollen hydrogel clearly depend on the crosslinker content. The high values of the degree of swelling in the exudate-simulating fluid in combination with mechanical strength allow the development of wound dressings based on hydrogels of the developed composition. Crosslinking of gelatin with PEGDE 500 allows to obtain gelatin-based hydrogels in a controlled manner which does not require subsequent purification steps. The resulting material does not exhibit cytotoxicity during in vitro studies on living cells. The hydrogel filled with an antiseptic drug is capable of releasing it by 50% within the first day into the medium of saline and exudate-simulating fluid. The antimicrobial properties of the hydrogel containing chlorhexidine are confirmed by the effective inhibition of the growth of Escherichia coli and Staphylococcus aureus bacteria.

N-GLYCOLYLNEURAMINIC ACID AS A POSSIBLE TRIGGER FOR IMMUNE REJECTION OF EPOXY-TREATED XENO-PERICARDIAL HEART VALVE BIOPROSTHESES

HighlightsStabilization of bovine pericardial tissue by ethylene glycol diglycidyl ether does not remove the N-glycolylneuraminic acid contained in its structure, which is one of the most immunoreactive glycan xenoantigens;N-glycolylneuraminic acid can potentially cause early immune rejection of epoxy-treated bioprosthetic heart valves. Aim. To assess the presence of N-glycolylneuraminic acid (Neu5Gc) in an intact bovine pericardial tissue stabilized by ethylene glycol diglycidyl ether and in the leaflets of epoxy-treated bioprosthetic heart valves (BHV) explanted due to dysfunction.Methods. By means of immunochemistry (using anti-Neu5Gc antibodies), we studied the fragments of 5 samples of intact epoxy-treated bovine pericardium commonly used in cardiac surgery. Similarly, we examined the fragments of the leaflets of 8 epoxy-treated BHVs that lasted for different time periods (1 day to 68 months) and excised during reoperation. The native bovine pericardium and the leaflets of 3 human aortic valves (AV) removed during reoperation in patients with aortic stenosis were used as positive and negative controls, respectively.Results. Positive reaction for Neu5Gc was observed in intact epoxy-treated xenopericardium and BHVs excised 1, 2, 20 and 42 days after implantation. The tissue of BHV that had lasted 30 months was characterized by the faint presence of Neu5Gc. In the leaflets of AV and in BHVs, explanted after 34, 63 and 68 months, Neu5Gc was not detected. Conclusion. Stabilization of xenobiomaterial with ethylene glycol diglycidyl ether does not remove the Neu5Gc. This saccharide remains in the biological tissue of epoxy-treated BHV for about 2.5 years after implantation.

Synthesis and properties of a nonionic water-based epoxy curing agent

Owing to the requirement for environmental protection, water-based coatings have become a significant trend in the development of coatings. The water-based epoxy curing agent has also become a hot research topic. In this study, a B-A-B epoxy compound with a long hydrophobic alkyl chain connected to the intermediate nitrogen atom was synthesized at both ends of a molecule using ethylene glycol diglycidyl ether and 3,4-dimethoxyaniline as raw materials. Subsequently, the epoxy compound was sealed with triethylenetetramine. A nonionic, water-based epoxy resin curing agent with amino groups at both ends of the molecule was prepared. The target product structure was confirmed by infrared spectroscopy (IR), Mass spectrum (MS), and Nuclear magnetic resonance hydrogen spectroscopy (1H-NMR). Additionally, through three factors and three levels of orthogonal experimental design, the optimum experimental conditions were confirmed, the optimum yield was 82.83%. The thermogravimetric analysis (TGA) indicated that the monomer exhibited a significant weight loss in the temperature range of 320–450°C. The pencil hardness, flexibility, and impact resistance of the waterborne epoxy resin coating film prepared by the non-ionic water-based epoxy curing agent reached or exceeded those of similar products at China and foreign countries.

Swelling of lignin-based gel in salt-containing organic solvents and its application as gel electrolyte

Abstract A lignin-based gel prepared by the chemical crosslinking of hardwood acetic acid lignin (AL) with poly(ethylene glycol) diglycidyl ether has been reported to shrink in water and organic solvents but swell specifically in aqueous binary solutions. In this study, the AL-based gel was also found to swell in lithium-salt-containing organic solvents, namely, liquid electrolytes. The uptake of salt solutions reached five times the dry weight of the gel. The ionic conductivity of the gel swollen with 1 M LiBF4 in propylene carbonate or a mixed solution (1:1, v/v) of ethylene carbonate and dimethyl carbonate exceeded 1 mS cm−1 at room temperature (25 °C), suggesting that this gel can be applied as a gel electrolyte for lithium-ion batteries (LIBs). A prototype LIB was assembled with the AL-based gel electrolyte and LiCoO2/graphite-based electrodes and exhibited low bulk and charge transfer resistances of 4.1 and 9.7 Ω, respectively. Moreover, its initial specific capacity reached 104 mAh g−1 at a current density of 28 mA g−1, which is comparable to that of a reference LIB assembled using a commercial polyethylene separator. These results indicate the significant potential of this lignin-based gel for application in energy storage devices.