P-toluenesulfonic Acid Research Articles

Preparation of single crystals of palmatine-sulfophenyl acids pharmaceutical salts by substituting Cl− in palmatine chloride to improve hygroscopic stability and antibacterial activity of palmatine and to preserve its solubility

To enhance the hygroscopic stability of palmatine chloride (PMTCl) while maintaining its solubility, several unexplored pharmaceutical salts of palmatine (PMT) were synthesised using benzenesulfonic acid (PMT-BSA), p-toluenesulfonic acid (PMT-PTSA), and aminobenzenesulfonic acid (PMT-SUL). These novel salts were thoroughly characterized using techniques such as single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), infrared spectroscopy (IR), and Hirshfeld surface analysis to determine their structural properties. Surprisingly, it was discovered that these salts exhibited improved antibacterial activity in addition to their enhanced hygroscopic stability. As anticipated, all three pharmaceutical salts demonstrated improved hygroscopic stability. This improvement might be attributed, to some extent, to the introduction of safe, stable, and less electronegative anions (BSA, PTSA, and SUL) to replace the more electronegative chloride (Cl−) in PMTCl. The replacement of Cl− hindered the binding of the pharmaceutical with external water molecules, thus increasing its resistance to moisture. Moreover, the interaction between PMT and the anions from the benzenesulfonic acid group via hydrogen bonding might have played a role in the improved hygroscopic stability. The crystal structure formed by the PMT molecules exhibited long-range order, while the benzenesulfonic acid anions cleverly avoided potential binding sites for water molecules. Additionally, the antibacterial activities of all three pharmaceutical salts were enhanced. This improvement can be attributed to the alteration of electron cloud density (ρe) in the isoquinoline group of PMT upon the introduction of benzenesulfonate anions to form the pharmaceutical salts. This hypothesis was supported by analyzing the molecular electrostatic potential, electron cloud density, and Hirshfeld surface. The successful outcome of this study suggests that modifying the ρe of the isoquinoline group in protoberberines through the introduction of benzenesulfonic acid anions to form pharmaceutical salts can potentially alter their physicochemical properties and biological activities. This finding paves the way for future research on improving the physicochemical properties of protoberberines-based pharmaceuticals.

Preparation and characterization of MnIIMnIII complexes with relevance to class Ib ribonucleotide reductases

The Mn2 complex [MnII2(TPDP)(O2CPh)2](BPh4) (1, TPDP = 1,3-bis(bis(pyridin-2-ylmethyl)amino)propan-2-ol, Ph =phenyl) was prepared and subsequently characterized via single-crystal X-ray diffraction, X-ray absorption, electronic absorption, and infrared spectroscopies, and mass spectrometry. 1 was prepared in order to explore its properties as a structural and functional mimic of class Ib ribonucleotide reductases (RNRs). 1 reacted with superoxide anion (O2•–) to generate a peroxido-MnIIMnIII complex, 2. The electronic absorption and electron paramagnetic resonance (EPR) spectra of 2 were similar to previously published peroxido-MnIIMnIII species. Furthermore, X-ray near edge absorption structure (XANES) studies indicated the conversion of a MnII2 core in 1 to a MnIIMnIII state in 2. Treatment of 2 with para-toluenesulfonic acid (p-TsOH) resulted in the conversion to a new MnIIMnIII species, 3, rather than causing O—O bond scission, as previously encountered. 3 was characterized using electronic absorption, EPR, and X-ray absorption spectroscopies. Unlike other reported peroxido-MnIIMnIII species, 3 was capable of oxidative O—H activation, mirroring the generation of tyrosyl radical in class Ib RNRs, however without accessing the MnIIIMnIV state.

Experimental and Dynamic Molecular Study of Zinc Extraction from Sphalerite Concentrate in Ternary Solvent Deep Eutectic Solvent

The utilization of deep eutectic solvents (DESs) as a novel class of solvents in hydrometallurgical processes for metal production offers a promising alternative to aqueous solutions due to their biocompatibility and non-aqueous nature. This study investigated the leaching of sphalerite concentrate using a ternary stable DES composed of choline chloride (ChCl), p-toluene sulfonic acid (PTSA), and ethylene glycol (EG) (at a molar ratio of 1:1:1). The effects of time, temperature, and milling time on zinc recovery were examined within specific ranges (20-1440min, 40-100 °C, and 0-24h, respectively). The study revealed the significant influence of time and temperature on zinc dissolution efficiency within ChCl:PTSA:EG. Higher temperatures and longer leaching times were found to substantially improve efficiency. The research emphasized the crucial role of milling time, demonstrating that longer durations enhanced efficiency by introducing more defects on the sphalerite surface and reducing particle size. Under optimized conditions, including a temperature of 100 °C, 24h of ball milling, and 1440min of leaching, a zinc recovery of 99.7% was achieved. Infrared analysis confirmed the chemical stability of the solvents during the leaching process. The zinc sulfide leaching process involved the formation of zinc chloride ion complexes and evolution H2S gas. An unexpected finding is the presence of lead sulfate in the leach residue, which may be attributed to sulfide oxidation to sulfate species. The Avrami kinetic model provided an excellent fit with the sphalerite dissolution data in ChCl:PTSA:EG DES, indicating that the rate-controlling step was primarily influenced by the diffusion process. R2 values for kinetics fitting data was in the range of 0.87 to 0.97 for temperature of 40 to 100 °C. The molecular dynamic (MD) simulation findings indicated robust electrostatic interactions between the metal ions Zn2+ and Fe2+ and the Cl− ions of the ChCl molecules. Additionally, the MD calculations showed that the metal ions formed complexes with some O-S-O atoms within the PTSA molecule.Top of FormBottom of Form

Evolution of morphology, structure, and performance of the COF membranes with monomer concentrations: Enabling effective desalination and kinetics analysis

Fabricating crystalline covalent organic framework (COF) membrane with sub-nanopores for desalination remains challenging. Monomer (p-phenylenediamine (Pa) and 1,3,5-triformylphloroglucinol (Tp)) concentration) was crucial to tailor the diffusion-reaction of monomers in the p-toluenesulfonic acid (PTSA)-mediated interfacial catalytic polymerization process for crystalline TpPa-COF membrane fabrication. By increasing monomer concentration, membrane surface color evolved from light yellow to dark orange. TpPa-COF layers with adjustable thickness (90.47–436 nm) transformed from amorphous to crystalline with crystalline and cross-linking degree increasing from 16.47 % to 73.90 %, and 66.40 % to 87.60 %, respectively. Pore size decreased from 1.69 to 0.17 nm, while Na2SO4 rejection significantly increased from 26.7 % to 90.4 %. A 3-day filtration test for RO concentrate demonstrated the stability and robust desalination performance with SO42− and Mg2+ rejection ratio of 74.3 ± 1.08 % and 65.6 ± 1.33 %, respectively. Diffusion behavior experiments demonstrated that diffusion coefficient for Pa-PTSA complex (6.49 × 10−5–8.87 × 10−5 cm2 s−1, Pa > 0.05 wt%) higher than Tp (3.53 × 10−6–6.39 × 10−6 cm2 s−1, Tp > 0.006 wt%) by one order of magnitude promoted structural crystallinity and regulated assembly at the interface, resulting in sub-nanopore TpPa-COF layers. This study highlighted the importance of monomer concentration on the COF membrane formation, providing valuable insights for the highly crystalline COF membrane fabrication.

Crystal structures, Hirshfeld surface analysis, thermogravimetric, and spectroscopic properties of three Zn(Ⅱ) complexes bridged by 4,4′-bipy with organic sulfonate anions as counterions

Three Zn(Ⅱ) sulfonate compounds: {[Zn3(Ac)4(4,4′-bipy)4]·2(3-pySO3)·H2O}n (1), {[Zn(4,4′-bipy)(H2O)4]·2(Me-phSO3)}n (2), and {[Zn(4,4′-bipy)(H2O)4]·2(NH2-phSO3)}n (3), were synthesized through solvent diffusion method at room temperature (3-pySO3H = Pyridine-3-Sulfonic acid; Me-phSO3H = P-Toluene Sulfonic acid; NH2-phSO3H = Sulfanilic acid). Single-crystal X-ray diffractions reveal that the crystal structure of compound 1 contains a 2D cationic layer with pseudo-square grid motifs formed by trinuclear Zn(II) units which connected by 4,4′-bipy ligands. Water molecule forms hydrogen bonds with free 3-PySO3− anions which are located in the voids of the cationic grids. Compounds 2 and 3 show isostructural 1D [Zn(4,4′-bipy)(H2O)4]2+ chains with sulfonate anions connected to the chain via hydrogen bonding. The weak interactions in the structures of the three compounds have been assessed using Hirshfeld surface analyses and 2D fingerprint plots. The Hirshfeld surface shows that the most important contributions for the crystal packing are from H···H and H··O/O··H interactions, which indicate dominant van der Waals interactions. In addition, the compounds were investigated by powder X-ray diffraction (PXRD), elemental analyses, UV–vis, FT-IR, solid-state fluorescence spectroscopy, and thermal analyses (TG-DSC).

Integrated Preparation of Hollow Lignin Nanoparticles as a Drug Carrier and Levulinic Acid from the Poplar Wood Prehydrolysis Liquor.

Prehydrolysis liquid (PHL) from dissolving pulp and biorefinery industries is rich in saccharides and lignin, being considered as a potential source of value-added materials and platform molecules. This study proposed an environmentally friendly and simple method to prepare morphologically controllable hollow lignin nanoparticles (LNPs) and levulinic acid (LA) from PHL. In the first step, after hydrothermal treatment of PHL with p-toluenesulfonic acid (p-TsOH), lignin with a uniform molecular weight was obtained to prepare LNPs. The prepared LNPs have an obvious hollow structure, with an average size of 490-660 nm, and exhibit good stability during 30 days of storage. When the as-obtained LNPs were used as a sustained-release agent for amikacin sulfate, the encapsulation efficiency reached over 70% and the release efficiency within 40 h reached 69.2% in a pH 5.5 buffer. Subsequently, the remaining PHL that contains saccharides was directly used for LA production under the catalysis of p-TsOH. At 150 °C for 1.5 h, the LA yield reached 58.4% and remained at 56% after 5 cycles of p-TsOH. It is worth noting that only p-TsOH was used as a reactive reagent throughout the entire preparation process. Overall, this study provided a novel pathway for the integrated utilization of PHL and showed the immense potential of the preparation and application of LNPs.

Lignin nanoparticles as a highly efficient adsorbent for the removal of methylene blue from aqueous media

This work demonstrated enhanced adsorption capabilities of lignin nanoparticles (LNPs) synthesized via a straightforward hydrotropic method compared to pristine lignin (PL) powder for removing methylene blue dye from aqueous solutions. Kraft lignin was used as a precursor and p-toluenesulfonic acid as the hydrotrope to produce spherical LNPs with ~ 200 nm diameter. Extensive characterization by SEM, AFM, DLS, zeta potential, and BET verified successful fabrication of microporous LNPs with fourfold higher specific surface area (14.9 m2/g) compared to PL (3.4 m2/g). Significantly reduced particle agglomeration and rearranged surface chemistry (zeta potential of −13.3 mV) arising from the self-assembly of lignin fractions under hydrotropic conditions enabled the application of LNPs and superior adsorbents compared to PL. Batch adsorption experiments exhibited up to 14 times higher methylene blue removal capacity, from 20.74 for PL to 127.91 mg/g for LNPs, and ultrafast equilibrium uptake within 3 min for LNPs compared to 10 min for PL. Kinetic modeling based on pseudo-first-order and pseudo-second-order equations revealed chemisorption as the predominant mechanism, with a rate constant of 0.032825 g/mg·h for LNPs—over an order of magnitude higher than PL (0.07125 g/mg·h). Isotherm modeling indicated Langmuir monolayer adsorption behavior on relatively uniform lignin surface functional groups. The substantially augmented adsorption performance of LNPs arose from the increased surface area and abundance of surface functional groups, providing greater accessibility of chemically active binding sites for rapid dye uptake. Overall, this work demonstrates that tailoring lignin nanoparticle structure and surface chemistry via scalable hydrotropic synthesis is a simple and sustainable approach for producing highly efficient lignin-based nano-adsorbents for organic dye removal from industrial wastewater.

P-Toluenesulfonic Acid Modified Two-Dimensional ZrSe2 as a Hole Transport Layer for High-Performance Organic Solar Cells.

Two-dimensional (2D) materials have attracted attention due to their excellent optoelectronic properties, but their applications are limited by their defects and vacancies. Surface modification is an effective method to restore their performance. Here, ZrSe2 is modified with conductive polymer p-toluenesulfonic acid (PTSA). It is found that PTSA can obtain electrons of ZrSe2 through the combination of -SO3H and ZrSe2, thus forming interfacial dipoles, which improve the work function of ZrSe2. In addition, -OH in PTSA can effectively fill the Se vacancy in ZrSe2 to form P-type doping, thereby improving its conductivity. ZrSe2 modified by the PTSA material is first used as a hole transport layer (HTL) in organic solar cells (OSCs). The efficiency of OSCs based on the PBDB-T:ITIC and PM6:L8-BO binary active layer with ZrSe2:PTSA as the novel HTL reaches 10.66 and 18.14%, which are obviously higher than the efficiency of OSCs with pure ZrSe2 as the HTL (8.48 and 15.64%). More interestingly, the stability of the device with ZrSe2:PTSA as HTL is significantly better than that of PEDOT:PSS. This study shows that the modification of the organic material can effectively improve the photoelectric performance of ZrSe2 and explores the physical mechanism of the interaction between the organic modifier and 2D materials.

Preparation of a functional monomer containing polymerisable double bonds and chain transfer sulfhydryl groups

ABSTRACT Methacrylate functional monomers containing polymerisable double bonds and sulphhydryl group were synthesised using (methyl) hydroxyethyl (propyl) acrylate and mercaptopropionic acid as precursors with benzene (toluene, ethyl acetate, ether) as solvent and aqueous agent, p-toluene sulphonic acid as catalyst, hydroquinone as polymerisation inhibitor. The yield of methacrylate functional monomers was more than 90%. The structure and purity of methacrylate functional monomers was characterised by proton nuclear magnetic resonance (1H-NMR) and liquid chromatography–mass spectrometry (LC-MS). The precursor material source is of low cost and widely available, and the product did not need to be purified by a special method, which means that it can be directly used for the synthesis of vinyl branched polymer. Therefore, the price of vinyl branched polymer can be greatly reduced and the application range of vinyl branched polymer can be greatly expanded.

PTSA-induced synthesis, in silico and nano study of novel ethylquinolin-thiazolo-triazole in cervical cancer.

Aim: p-Toluenesulfonic acid-(PTSA) and grinding-induced novel synthesis of ethylquinolin-thiazolo-triazole derivatives was performed using green chemistry. Materials & methods: Development of a nanoconjugate drug-delivery system of ethylquinolin-thiazolo-triazole was carried out with D-α-tocopheryl polyethylene glycol succinate (TPGS) and the formulation was further characterized by transmission electron microscopy, atomic force microscopy, dynamic light scattering and in vitro drug release assay. The effect of 3a nanoparticles was assessed against a cervical cancer cell line (HeLa) through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the effect on apoptosis was determined. Results & discussion: The 3a nanoparticles triggered the apoptotic mode of cell death after increasing the intracellular reactive oxygen level by enhancing cellular uptake of micelles. Furthermore, in silico studies revealed higher absorption, distribution, metabolism, elimination and toxicity properties and bioavailability of the enzyme tyrosine protein kinase. Conclusion: The 3a nanoparticles enhanced the therapeutic potential and have higher potential for targeted drug delivery against cervical cancer.

Conversion of 5-hydroxymethylfurfural and carbohydrates to 5-ethoxymethylfurfural over chitin-derived solid acid catalysts

The use of environment friendly biomass-based catalysts in bio refinery is highly desirable. In this paper, the preparation of sulfonated carbon materials from biopolymers (typically chitin and cellulose) via facile one-step carbonization and sulfonation using p-toluenesulfonic acid as sulfonating agent was demonstrated. Unlike nitrogen-free cellulose, the basic nitrogen-containing sites generated from chitin decreased the acidity strength of the catalysts, which was confirmed by the results of 31P Nuclear Magnetic Resonance (31P NMR). The suppressed acidity strength boosted the selectivity of 5-ethoxymethylfurfural (EMF) from 5-hydroxymethylfurfural (HMF) by inhibiting the formation of by-products, such as ethyl levulinate (EL) and humins. An 84.3 % yield of EMF from HMF was obtained over the as-prepared chitin-derived solid acid. The catalyst could be reused at least three times without obvious decrease of catalytic activity. Moreover, 74.6 %, 31.9 % and 60.7 % yields of EMF were obtained from fructose, sucrose and inulin in ethanol-containing solvents, respectively. This work offers an example for the synthesis of biofuels using biomass-derived catalysts.

Integrated preparation of functional lignin nanoparticles and levulinic acid directly from the pre-hydrolysis liquor of poplar wood

The pre-hydrolysis liquor (PHL) produced during pulp dissolution and biomass refining is mainly composed of hemicellulose and lignin, and it is a potential source for production of value-added materials and platform chemicals; however, their utilization has been a serious challenge. In this study, we proposed a green and simple strategy to simultaneously prepare size-controlled functional lignin nanoparticles (LNPs) and levulinic acid (LA) from PHL as the raw material. The as-prepared LNPs exhibited remarkable stability thanks to the presence of saccharides with abundant oxygen-containing groups and surface charges, which prevented aggregation and maintained long-term storage stability. Trace amounts of the LNPs (≤ 0.2 wt%) could stabilize various Pickering emulsions, even with oil-to-water ratios as high as 5:5 (v/v). Subsequently, the remaining PHL was directly used to produce LA without adding a catalyst; under optimal conditions (160 °C and 1 h), the yield of LA was 56.3 % based on the dry saccharide content in the raw PHL. More importantly, p-toluenesulfonic acid (p-TsOH), the only reactive reagent used during the entire preparation process, including the two preparation steps of the LNPs and LA, was reusable, and the recovery rate was >70 % after five cycles. Overall, this green and simple strategy effectively and comprehensively utilized the PHL and showed potential for producing biobased nanomaterials and platform chemicals.

Complete kinetic model for esterification reaction of lauric acid with glycerol to synthesize glycerol monolaurate

Glycerol monolaurate (GML) is a widely used industrial chemical with excellent emulsification and antibacterial effect. The direct esterification of glycerol with lauric acid is the main method to synthesize GML. In this work, the kinetic process of direct esterification was systematically studied using p-toluenesulfonic acid as catalyst. A complete kinetic model of consecutive esterification reaction has been established, and the kinetic equation of acid catalysis was deduced. The isomerization reactions of GML and Glycerol dilaurate were investigated. It was found that the reaction was an equilibrium reaction and the reaction rate was faster than the esterification reaction. The kinetic equations of the consecutive esterification reaction were obtained by experiments as k1=(276+92261Xcat)exp(−37720/RT) and k2=(80+4413Xcat)exp(−32240/RT). The kinetic results are beneficial to the optimization of operating conditions and reactor design in GML production process.

Preparing vegetable oils-based metalworking fluids by a hydrolysis-esterification two-step process

Oil-soluble esters of free fatty acids were synthesized with a 2-step process including the first step of reacting vegetable oil with water in the presence of sulfuric acid and p-Toluenesulfonic acid as a catalyst, followed by removing water and glycerol, and the second step of reacting the obtained free fatty acids with various polyhydric and fatty alcohols. The best conditions were 190 °C, 6 h, 30 to 1 water to oil molar ratio, 5 wt% PTSA catalyst loading in the hydrolysis reaction (the 1st step), and 150 °C, 10 h, 4 to 1 fatty acid to trimethylolpropane molar ratio, 1 wt% PTSA catalyst loading in the esterification reaction (the 2nd step). Under the best conditions, the process achieved the final product with the 87% yield of free fatty acid trimethylolpropane ester and 82% conversion of free fatty acid. Different esters were made concurring to the aforementioned conditions with distinctive polyhydric and fatty alcohols. Hydrolysis reactions facilitated by catalysts offer an alternative approach to traditional hydrolysis in supercritical conditions, enabling efficient substrate conversion under milder operating conditions. Furthermore, the inclusion of the obtained esters mixed with base oil and additives produced bio-based metalworking fluids with exceptionally lubricant performance in wear resistance, with a wear scar diameter of 0.33 mm.

In-situ approach to porous nitrogen-doped carbon nanosheets functionalized by Brønsted acidic ionic liquids for microwave-assisted upgrading fructose to 5-hydroxymethylfurfural

In the search for robust and recoverable supported Brønsted acidic ionic liquids (BAILs) catalysts for efficient upgrading bio-sugars to value-added chemicals, an in-situ strategy of supramolecular preorganization-thermal polycondensation is designed to fabricate porous ultrathin nitrogen-doped carbon nanosheets (NCNSs), and then BAILs-functionalized NCNSs catalysts are prepared via successive quaternary ammonization by sultones and anion exchange with Brønsted acids. By adjusting the molar composition of the starting monomers, the textural properties of NCNSs supports are tuned; and by functionalization with different sultones (1,3-propanesultone and 1,4-butanesultone) and organic (trifluoromethanesulfonic acid and p-toluenesulfonic acid) or inorganic (H2SO4 and H3PO4) acids, the surface hydrophobicity and Brønsted acid strength of the catalysts are regulated. The catalysts are applied in microwave-assisted upgrading fructose to 5-hydroxymethylfurfural, and influences of Brønsted acid nature, surface hydrophobicity and textural properties on the catalytic performance are explored. For the most active [C4SO3HN][OTf]-NCNSs-MA-3 catalyst with the advantages of superstrong Brønsted acidity, higher surface hydrophobicity and perfect porous ultrathin sheet-like nanostructure, the conversion of fructose and the yield of 5-hydroxymethylfurfural of 100% and 87.7% are achieved after microwave irradiation for 15 min, outperforming Amberlyst-15 resin and HY zeolite. The catalysts also demonstrate the robust catalytic reusability, and after five consecutive catalytic runs, the obvious activity loss hardly occurs, along with little acid sites leaching.

Brønsted Acid-Catalyzed Diastereoselective Synthesis of Spiroisoindolinones from Enamides.

A highly diastereoselective synthesis of spiroisoindolinones from enamides and 3-hydroxy-isoindolinones is reported. The reaction proceeds rapidly in the presence of p-toluenesulfonic acid as a Brønsted acid catalyst and affords a variety of densely substituted spiroisoindolinones with three contiguous stereogenic centers in high yields (≤98%) and diastereoselectivities (up to dr >98:<2:0:0).

Facile synthesis of functional binaphthyl-based hyperbranched polyarylenes by organo-catalyzed alkyne polycyclotrimerization

Binaphthyl-based polymers have attracted increasing interest due to their unique properties and wide applications. Nevertheless, binaphthyl-containing hyperbranched polymers are rarely reported. Herein, two binaphthyl-based hyperbranched polyarylenes with high molecular weights were facilely synthesized in satisfactory yields by the polycyclotrimerization of internal diynes containing binaphthyl units in 1,2,4-trichlorobenzene (TCB) under heating in the presence of p-toluenesulfonic acid monohydrate (p-TsOH·H2O). The resultant polymers are soluble in common organic solvents, and thermally stable with 5% weight loss temperatures higher than 380 °C. They showed electrochemical properties, and optical activities. Furthermore, the polymer-doped polyvinyl alcohol (PVA) films exhibited yellow room-temperature phosphorescence (RTP) with the lifetime longer than 630 ms.

Combination of microwave with acid deep eutectic solvent pretreatment for reed (Phragmites australis) fractionation

The cost-effective and low-carbon fractionation of lignocellulosic biomass will enhance the economic viability of bio-refining. To achieve efficient reed fractionation under favorable conditions, microwave-assisted choline chloride and p-toluene sulfonic acid (M-ChCl/p-TsOH) pretreatment was employed. The fractionation of reed components demonstrated higher effectiveness with M-ChCl/p-TsOH pretreatment compared to conventional DES pretreatment. Under M-ChCl/p-TsOH conditions, a high hemicellulose removal rate (∼90%) and delignification rate (∼65%) were achieved while achieving a saccharification rate of 88% during cellulase hydrolysis. Microwave assistance not only significantly reduced reaction time to less than 60 s but also enhanced the pretreatment efficacy. Furthermore, the obtained lignin products consisted of low-polymerization lignin (MW < 800 g/mol) and acid-soluble lignin, providing a solid foundation for subsequent high-value utilization of lignin. This study provides a promising strategy for the low carbon fractionation of reed using DES, aiming to simultaneously achieve efficient cellulose hydrolysis and obtain tractable lignin.

Investigation into the characteristics of bagasse processed with 3C-DES and the production of chemimechanical pulp for pulp molded

Pulp molded generated from renewable bagasse as biodegradable packaging materials has been widely viewed as an eco-friendly and cheap way to substitute the current huge consumption of nondegradable plastics, and deep eutectic solvents (DES) pretreatment are a promising approach to obtain high-yield pulp efficiently and sustainably. However, mainstream binary-component DES still suffers issues of high viscosity and corrosiveness. This study put forward a ternary-component DES (3C-DES) with the addition of ethylene glycol (EG) into choline chloride (ChCl) and P-toluenesulfonic acid (PTSA) and examined pretreatment performance and optimal DES ratio for thread rolling bagasse via compositional analysis and physicochemical characterization. Moreover, density functional theory calculations were used to reveal structures and weak interactions of different ratios of 3C-DES, and a novel 3C-DES pretreatment chemical-mechanical pulp and pulp molded were finally prepared. The results indicate that the 3C-DES with ChCl:PTSA:EG molar ratio of 1:1:3 is most effective, evidenced by more than 97.94% lignin removals. The 3C-DES pretreated mechanical pulp exhibits superior fiber properties, whereas the hot-pressed pulp molded shows excellent physical properties and thermal stability. Thus, the proposed 3C-DES has great potential to obtain high-yield high-performance pulp molded with low cost and environmental sustainability.

A Molecular Modeling Study into Brønsted and Lewis Acid Catalyzed Conversion of CBD into Other Cannabinoids

A Molecular Modeling Study into Brønsted and Lewis Acid Catalyzed Conversion of CBD into Other Cannabinoids