Acid Chloride Research Articles

Manufacturing Options for Activated Carbons with Selected Synthetic Polymers as Binders.

Formed activated carbon (AC) is a multipurpose product with developed adsorption properties that is widely used in various areas of life. To create AC, hard coal has to go through various processes: grinding, granulation, carbonization, physical and/or chemical activation. Presented research was conducted in the professional company manufacturing activated carbons. Studied AC reached the demanded shape of grains thanks to binders added to granulation process. Research on the AC formed using new polymeric binders (applied so far in other branches: pharmacy and construction materials) is presented in this manuscript. Tested binders were not used before to manufacture ACs in the professional technological line. Such polymers as: sodium carboxymethylhydrocellulose (CMHC), poly[1-(2-oxo-1-pyrrolidinyl)ethylene] (POPE) and enriched methyl-hydroxypropyl cellulose MHPC were studied in this work. Conducted research has proven efficiency of 8% CMHC which allowed for proper granulation and carbonization and reached the best parameters. Single- and double-stage activation was investigated for AC with this binder. For newly manufactured AC BET surface and pore volume increased accordingly from 774 m2/g and 0.58 cm3/g (1-stage) to 968 m2/g and 0.72 cm3/g (2-stage). Chemical elemental features of surface of the best AC showed beside elementary carbon also calcium, silicon and aluminum ions as well as groups with an acidic character, phosphates, sulphates and chlorides. The new AC had a higher Mechanical Strength reaching 99.9% and a lower Ash content and Volatile Matter than AC manufactured with previous binder-molasse. The new AC is intended to be directed for full production line and implementation to usage after positive certification. It may be useful in water treatment. It will also find application in the treatment of industrial and municipal wastewater.

Unlocking the Power of Acyl Fluorides: A Comprehensive Guide to Synthesis and Properties

AbstractAcyl fluorides have emerged as versatile reagents in various synthetic endeavors, offering a range of advantages over their counterparts, acyl chlorides. This study delves into the properties and reactivity of acyl fluorides, particularly their reaction with amines and alcohols, to elucidate their distinct characteristics. We also introduce a facile and practical synthesis of acyl fluorides from a stable solution of CF3O− salt. Additionally, we establish an efficient one‐pot process for the direct preparation of amides or esters from corresponding acids and amines or alcohols, showcasing the remarkable efficiency of acyl fluorides in these transformations.

Gas-Phase Functionalization of Phytoglycogen Nanoparticles and the Role of Reagent Structure in the Formation of Self-Limiting Hydrophobic Shells.

A suite of acyl chloride structural isomers (C6H11OCl) was used to effect gas-phase esterification of starch-based phytoglycogen nanoparticles (PhG NPs). The surface degree of substitution (DS) was quantified using X-ray photoelectron spectroscopy, while the overall DS was quantified using 1H NMR spectroscopy. Gas-phase modification initiates at the NP surface, with the extent of surface and overall esterification determined by both the reaction time and the steric footprint of the acyl chloride reagent. The less sterically hindered acyl chlorides diffuse fully into the NP interior, while the branched isomers are restricted to the near-surface region and form self-limiting hydrophobic shells, with shell thicknesses decreasing with increasing steric footprint. These differences in substitution were also reflected in the solubility of the NPs, with water solubility systematically decreasing with increasing DS. The ability to separately control both the surface and overall degree of functionalization and thereby form thin hydrophobic shells has significant implications for the development of polysaccharide-based biopolymers as nanocarrier delivery systems.

Masked acid chlorides for proximity labelling of RNA.

Masked acid chlorides for proximity labelling of RNA.

Improving the thermal conductivity of an epoxy composite with chemically boron nitride-grafted carbon fiber

The rapid progress of electronic devices like electric vehicles, smartphones, and IoT systems has fueled the demand for compact, high-performance batteries. However, a critical challenge arises from heat accumulation within these devices, leading to malfunctions and reduced efficiency. To address this, efficient heat dissipation is crucial, with thermal interface materials (TIMs) widely used for heat transfer. While polymers are favored for TIMs due to their ease of processing and electrical insulation, their low thermal conductivity poses limitations. In this study, a solution is proposed by chemically grafting boron nitride (BN), a ceramic-based filler, onto carbon fiber (CF) surfaces. This BN-g-CF hybrid filler, formed through a reaction between acyl chlorides and amine groups, exhibits superior compatibility with polymer matrix. Characterization confirms successful treatment, and thermal conductivity measurements show a remarkable enhancement, positioning the BN-g-CF/epoxy resin composite as a promising solution for efficient thermal management in various electronic industries.

Optimizing invasive plant biomass valorization: Deep eutectic solvents pre-treatment coupled with ZSM-5 catalyzed fast pyrolysis for superior bio-oil quality

The primary objective of this study is to explore the application of a deep eutectic solvent, synthesized from lactic acid and choline chloride, in combination with a pre-treatment involving ZSM-5 catalytic fast pyrolysis, aimed at upgrading the quality of bio-oil. Characterization results demonstrate a reduction in lignin content post-treatment, alongside a significant decrease in carboxyls and carbonyls, leading to an increase in the C/O ratio and noticeable enhancement in crystallinity. During catalytic fast pyrolysis experiments, the pre-treatment facilitates the production of oil fractions, achieving yields of 54.53% for total hydrocarbons and 39.99% for aromatics hydrocarbons under optimized conditions. These findings validate the positive influence of the deep eutectic solvent pre-treatment combined with ZSM-5 catalytic fast pyrolysis on the efficient production of bio-oil and high-value chemical derivatives..

Surface modification of nanofiltration membrane using quaternary diethanolamine for efficient antibiotics/salt separation

Nanofiltration plays a crucial role in antibiotic desalination from high salinity water, but the membranes often have low water permeability and insufficient selectivity between antibiotics and salts. In this study, a Gemini-type quaternary diethanolamine monomer (QTDEA) containing quaternary ammonium and hydroxyl groups was synthesized. This monomer had a hybrid spatial structure combining both rigid and flexible components, allowing it to covalently graft to the acyl chloride groups on the nascent polyamide (PA) film. The resulting modified PA-QTDEA membrane exhibited enhanced hydrophilicity, reduced negative charge, and a looser structure. It demonstrated a high water permeance of 18.2 L m−2 h−1·bar−1 for chlortetracycline hydrochloride (CTC) desalination from a NaCl solution of 10 g L−1, and the NaCl/CTC selectivity was 21.2. This research presents an efficient method for improving the performance of antibiotic desalination through surface modification using the novel QTDEA monomer.

Enhancing Freeze Tolerance of Field-grown Lettuce with Salicylic Acid, Ascorbic Acid, and Calcium Chloride

With the climate continuing to change, specialty crop growers are particularly at risk for economic loss caused by erratic weather conditions, excess heat and rain, and frost damage. Although tolerant to cold, lettuce (Lactuca sativa) is a major horticultural crop at risk for exposure to freezing temperatures in late fall or early spring in the Midwest. Exogenous applications of salicylic acid, ascorbic acid, and calcium chloride have been shown to improve abiotic stress in plants, particularly with freezing tolerance. This research investigated the effects of the exogenous application of salicylic acid, ascorbic acid, and calcium chloride, in varying concentrations, on field-grown lettuce. The study was conducted at the Iowa State University Horticulture Research Station, Ames, IA, USA. Weekly applications of salicylic acid (0.5 and 1.0 mM), ascorbic acid (0.5 and 1.0 mM), and calcium chloride (10 and 20 mM) were applied until plants were a marketable size. A control treatment (no spray) was also included. Data regarding plant size, yield, leaf area, leaf number, plant dry weight, plant nutrient analysis, and freeze tolerance were collected. Freeze tolerance assessments were conducted through laboratory-simulated freeze events and the evaluation of natural in-field freeze events. Freeze injury was quantified through the electrolyte leakage method. Marketable weights in 2020 and 2021 were statistically similar, except for 1.0 mM salicylic acid in 2020, which showed a significantly lower marketable weight and head diameter. Trends during both years showed that stress protectant applications had the most effective freeze protection at −12 °C in laboratory-simulated freeze events. Calcium chloride at 20 mM had the highest protection at −12 °C, with 13.3% and 24.0% less injury compared with the control in 2020 and 2021, respectively. Salicylic acid 1.0 mM at −12 °C had 4.7% and 23.7% less injury compared with control during these two years, respectively. Ascorbic acid 1.0 mM at −12 °C also showed 6.8% and 9.5% less injury than the control in 2020 and 2021, respectively. Similar trends were observed after in-field freezing events, with 20 mM calcium chloride providing the highest protection against frost in 2020 and 2021. These findings advance the understanding of the capabilities of stress protectants on lettuce as chemical primers after freezing events. This research highlights the benefits of ascorbic acid, salicylic acid, and calcium chloride as stress protectants and encourages future research and further exploration of concentrations, methods of application, and timing of application of products.

Synthesis, molecular docking analysis, drug-likeness evaluation, and inhibition potency of new pyrazole-3,4-dicarboxamides incorporating sulfonamide moiety as carbonic anhydrase inhibitors.

A series of novel pyrazole-dicarboxamides were synthesized from pyrazole-3,4-dicarboxylic acid chloride and various primary and secondary sulfonamides. The structures of the new compounds were confirmed by FT-IR, 1H-NMR, 13C-NMR, and HRMS. Then the inhibition effects of newly synthesized molecules on human erythrocyte hCA I and hCA II isoenzymes were investigated. Ki values of the compounds were in the range of 0.024-0.496 µM for hCA I and 0.006-5.441 µM for hCA II. Compounds 7a and 7i showed nanomolar level of inhibition of hCA II, and these compounds exhibited high selectivity for this isoenzyme. Molecular docking studies were performed between the most active compounds 7a, 7b, 7i, and the reference inhibitor AAZ and the hCAI and hCAII to investigate the binding mechanisms between the compounds and the isozymes. These compounds showed better interactions than the AAZ. ADMET and drug-likeness analyses for the compounds have shown that the compounds can be used pharmacologically in living organisms.

Design and Synthesis of Aspirin-chalcone Mimic Conjugates as Potential Anticancer Agents.

Extensive research has been conducted on aspirin, a widely recognized NSAID medication, regarding its potential as an anticancer agent. Studies have revealed its ability to trigger cell death in different types of cancer cells. A set of aspirin-chalcone mimic conjugates 5a-k and 6a-d utilizing the freshly prepared acid chloride of aspirin moiety has been designed and synthesized. To evaluate the newly developed compounds, the NCI 60- cell line panel was employed to assess their anti-proliferative properties. Subsequently, cell cycle analysis was conducted along with an examination of the compounds' impact on the levels of p53, Bax, Bcl-2, active caspase- 3, and their inhibition mechanism of tubulin polymerization. Derivative 6c displayed the best anticancer activity among the tested series while 6d was the best against breast cancer MDA-MB-468, therefore both of them were selected for the 5-dose stage, however, targeting MDA-MB-468, PI-flow cytometry of compound 6d proved the triggered cell growth arrest at the G1/S phase avoiding the mitotic cycle in MDA-MB-468 cells. Similarly, the upregulation of oncogenic parameters such as caspase-3, p53, and Bax/Bcl-2, along with the inhibition of PARP-1 enzyme level, was observed with compound 6d. This compound also exhibited a significant ability to induce apoptosis and disrupt the intracellular microtubule network through a promising activity as a tubulin polymerization inhibitor with IC50 = 1.065 ± 0.024 ng/ml. Furthermore, to examine the manner in which compound 6d binds to the active pocket of the tubulin polymerization enzyme, a molecular docking study was conducted. The study indicated that compound 6d could be a powerful microtubule-destabilizing agent. Therefore, further research on 6d could be worthwhile.

Development of novel pyrimidine nucleoside analogs as potential anticancer agents: Synthesis, characterization, and In-vitro evaluation against pancreatic cancer

The present study proposed modification of 5-FU by conjugation with an acyl chloride and a 5-membered heterocyclic ring to improve its in-vitro cytotoxicity and metabolic stability. XYZ-I-71 and XYZ-I-73 were synthesized by introducing a tetrahydrofuran ring on 5-fluorocytosine (a precursor of 5-FU) and conjugation with octanoyl chloride and lauroyl chloride, respectively. The structure of the synthesized compounds was validated using NMR and micro-elemental analysis. The antiproliferative activity of the analogs was determined against MiaPaCa-2, PANC-1, and BxPC-3 pancreatic cancer cells. The analog's stability in human liver microsomes was quantified by HPLC. We found that the XYZ-I-73 (IC50 3.6 ± 0.4 μM) analog was most effective against MiaPaCa-2 cells compared to XYZ-I-71(IC50 12.3 ± 1.7 μM), GemHCl (IC50 24.2 ± 1.3 μM), Irinotecan (IC50 10.1 ± 1.5 μM) and 5-FU (IC50 13.2 ± 1.1 μM). The antiproliferative effects of this analog in Miapaca-2 cells is evident based on it having a 7-fold,3-fold, and 4-fold increased cytotoxic effect over Gem-HCl, Irinotecan, and 5-FU, respectively. On the other hand, XYZ-I-71 exhibited a 2-fold increased cytotoxic effect over Gem-HCl but a comparable cytotoxic effect to 5-FU and Irinotecan in MiaPaCa-2 cells. A similar trend of higher XYZ-I-73 inhibition was observed in PANC-1 and BxPC-3 cultures. For 48-h MiaPaCa-2 cell migration studies, XYZ-I-73 (5 μM) significantly reduced migration (# of migrated cells, 168 ± 2.9), followed by XYZ-I-71(315±2.1), Gem-HCl (762±3.1) and 5-FU (710 ± 3.2). PARP absorbance studies demonstrated significant inhibition of PARP expression of XYZ-I-73 treated cells compared to 5-FU, GemHCl, and XYZ-I-71. Further, BAX and p53 expressions were significantly increased in cells treated with XYZ-I-73 compared to 5-FU, GemHCl, and XYZ-I-71. In-vitro, metabolic stability studies showed that 80 ± 5.9% of XYZ-I-71 and XYZ-I-73 remained intact after 2 h exposure in liver microsomal solution compared to 5-FU. The XYZ-I-73 analog demonstrated a remarkable cytotoxic effect and improved in-vitro metabolic stability over the selected standard drugs and may have potential anticancer activity against pancreatic cancer.

Photoredox-Catalyzed Acylchlorination of α-CF3 Alkenes with Acyl Chloride and Application as Masked Access to β-CF3-enones.

We disclose a photocatalytic strategy that simultaneously addresses the construction of trifluoromethylated quaternary carbon centers and the preparation of β-CF3-enones through radical difunctionalization of α-CF3 alkenes with acyl chlorides. This method is characterized by its broad functional group compatibility, high efficiency, and atom economy. The versatility of this transformation is poised to broaden the applications of α-CF3 alkenes, providing new pathways for the rapid assembly of structurally diverse fluorinated compounds.

Acylated Inulin as a Potential Shale Hydration Inhibitor in Water Based Drilling Fluids for Wellbore Stabilization.

Shale hydration dispersion and swelling are primary causes of wellbore instability in oil and gas reservoir exploration. In this study, inulin, a fructo-oligosaccharide extracted from Jerusalem artichoke roots, was modified by acylation with three acyl chlorides, and the products (C10-, C12-, and C14-inulin) were investigated for their use as novel shale hydration inhibitors. The inhibition properties were evaluated through the shale cuttings hot-rolling dispersion test, the sodium-based bentonite hydration test, and capillary suction. The three acylated inulins exhibited superb hydration-inhibiting performance at low concentrations, compared to the commonly used inhibitors of KCl and poly (ester amine). An inhibition mechanism was proposed based on surface tension measurements, contact angle measurements, Fourier-transform infrared analysis, and scanning electron microscopy. The acylated inulin reduced the water surface tension significantly, thus, retarding the invasion of water into the shale formation. Then, the acylated inulin was adsorbed onto the shale surface by hydrogen bonding to form a compact, sealed, hydrophobic membrane. Furthermore, the acylated inulins are non-toxic and biodegradable, which meet the increasingly stringent environmental regulations in this field. This method might provide a new avenue for developing high-performance and ecofriendly shale hydration inhibitors.

Carbon dots regulating microstructure of polyamide layer of forward osmosis membrane for anti-biofouling and unexpected dual-enhancement in water flux and salt rejection

The introduction of hydrophilic nanomaterials into the polyamide (PA) layer of forward osmosis (FO) membranes usually leads to the enhancement in water flux but a reduction in salt rejection. The decrease in salt rejection, however, inevitably influences the osmotic efficiency and operation cost. In this work, m-phenylenediamine (MPD), one of the chemicals of interfacial polymerization, was utilized as a precursor to synthesize carbon dots (MPD-C-dots) with a good photosensitization functionality. The MPD-C-dots were introduced into the PA layer of FO membranes through co-interfacial polymerization (denoted as Single-C-dots-M), and further grafted onto the PA layer by the conjugation of the residual acyl chloride of trimesoyl chloride with the amine of MPD-C-dots (denoted as Double-C-dots-M). The as-prepared Double-C-dots-M exhibited more outstanding FO performances than the pristine membrane (Control-M) and Single-C-dots-M. Most unexpectedly, the dual-enhancement in water flux and salt rejection of Double-C-dots-M was found. The further studies reveal that Double-C-dots-M had smaller and more uniform pore size, but larger porosity than the other two. In addition, the biofouling-resistance tests demonstrate that MPD-C-dots-M had an excellent anti-biofouling performance by generating singlet oxygen (1O2) under light irradiation. The proposed Double-C-dots-M provided a typical protocol for improving the performances of FO membrane, especially for the synchronous enhancement in water flux and salt rejection.

The Effects of the Steroids 5-Androstenediol and Dehydroepiandrosterone and Their Synthetic Derivatives on the Viability of K562, HeLa, and Wi-38 Cells and the Luminol-Stimulated Chemiluminescence of Peripheral Blood Mononuclear Cells from Healthy Volunteers.

In order to evaluate the role of substituents at 3-C and 17-C in the cytotoxic and cytoprotective actions of DHEA and 5-AED molecules, their derivatives were synthesized by esterification using the corresponding acid anhydrides or acid chlorides. As a result, seven compounds were obtained: four DHEA derivatives (DHEA 3-propionate, DHEA 3-butanoate, DHEA 3-acetate, DHEA 3-methylsulfonate) and three 5-AED derivatives (5-AED 3-butanoate, 5-AED 3,17-dipropionate, 5-AED 3,17-dibutanoate). All of these compounds showed micromolar cytotoxic activity toward HeLa and K562 human cancer cells. The maximum cytostatic effect during long-term incubation for five days with HeLa and K562 cells was demonstrated by the propionic esters of the steroids: DHEA 3-propionate and 5-AED 3,17-dipropionate. These compounds stimulated the growth of normal Wi-38 cells by 30-50%, which indicates their cytoprotective properties toward noncancerous cells. The synthesized steroid derivatives exhibited antioxidant activity by reducing the production of reactive oxygen species (ROS) by peripheral blood mononuclear cells from healthy volunteers, as demonstrated in a luminol-stimulated chemiluminescence assay. The highest antioxidant effects were shown for the propionate ester of the steroid DHEA. DHEA 3-propionate inhibited luminol-stimulated chemiluminescence by 73% compared to the control, DHEA, which inhibited it only by 15%. These data show the promise of propionic substituents at 3-C and 17-C in steroid molecules for the creation of immunostimulatory and cytoprotective substances with antioxidant properties.

A supramolecular hydrogel dressing with antibacterial, immunoregulation, and pro-regeneration ability for biofilm-associated wound healing

Chronic wound treatment has emerged as a significant healthcare concern worldwide due to its substantial economic burden and the limited effectiveness of current treatments. Effective management of biofilm infections, regulation of excessive oxidative stress, and promotion of tissue regeneration are crucial for addressing chronic wounds. Hydrogel stands out as a promising candidate for chronic wound treatment. However, its clinical application is hindered by the difficulty in designing and fabricating easily and conveniently. To overcome these obstacles, we present a supermolecular G-quadruplex hydrogel with the desired multifunction via a dynamic covalent strategy and Hoogsteen-type hydrogen bonding. The G-quadruplex hydrogel is made from the self-assembly of guanosine, 2-formylphenyboronic acid, polyethylenimine, and potassium chloride, employing dynamic covalent strategy and Hoogsteen-type hydrogen bonding. In the acidic/oxidative microenvironment associated with bacterial infections, the hydrogel undergoes controlled degradation, releasing the polyethylenimine domain, which effectively eliminates bacteria. Furthermore, nanocomplexes comprising guanosine monophosphate and manganese sulfate are incorporated into the hydrogel skeleton, endowing it with the ability to scavenge reactive oxygen species and modulate macrophages. Additionally, the integration of basic fibroblast growth factor into the G-quadruplex skeleton through dynamic covalent bonds facilitates controlled tissue regeneration. In summary, the facile preparation process and the incorporation of multiple functionalities render the G-quadruplex hydrogel a highly promising candidate for advanced wound dressing. It holds great potential to transition from laboratory research to clinical practice, addressing the pressing needs of chronic wound management.

Determination of triazole fungicides in soybeans with cobalt-enhanced lanthanide metal chloride anion magnetic deep eutectic solvents in-situ dispersion extraction

In this work, we synthesized a series of magnetic deep eutectic solvents (MDESs) with lanthanide metal chlorides as paramagnetic metal centers and developed a reversed-phase dispersive liquid–liquid microextraction method (DLLME) based on the in-situ dispersion of MDESs for the extraction and preconcentration of triazole fungicides (TFs) from bean samples. Different MDESs were synthesized by combining quaternary ammonium salts, short-chain carboxylic acids, and lanthanide metal chlorides. The dissolution of short-chain carboxylic acids in n-hexane led to the in-situ dispersion of MDESs to replace the toxic dispersant of traditional DLLME species and shorten extraction time. Cobalt powder was added to encapsulate MDESs to enhance the magnetic properties after the extraction and achieve the purpose of easy phase separation. Notably, the highest extraction efficiency of TFs was observed in the MDES formed by tetrabutylammonium bromide, propionic acid, and gadolinium chloride in a ratio of 1:10:0.06. We optimized various parameters that affected the extraction efficiency of the method, including volume of MDES, extraction time, amount of cobalt powder, and volume of elution solvent. Under the optimal conditions, the detection limits (LODs) and quantification limits (LOQs) of the technique varied between 0.097–0.13 ng·g−1 and 0.32–0.43 ng·g−1, respectively. To assess the accuracy, the method was tested with samples spiking at three concentration levels, and the obtained results revealed that the recovery rates varied from 88.97–113.7%. To summarize, this study represents the initial application of in-situ dispersed lanthanide metal chloride anion-MDESs for analyzing bean samples and the proposed DLLME technique is rapid, straightforward, and efficient.

Interfacial regulation of biomass-derived carbon towards high-performance supercapacitor

Interfacial regulation for carbon-based materials plays critical role for supercapacitive performance improvement and the strategies about introducing heteroatomic groups and tuning specific surface area can be proposed to effectively address the low specific capacitance issues. Thus, the approaches about activation treatment with nitric acid (APC-H800) and copper chloride (APC-C800) for biomass-derived carbon materials have been raised and systematically investigated. Consequently, though the above chemical activation treatment, the oxygen and nitrogen functional groups can be introduced for APC-H800. Meanwhile, the specific surface area of APC-C800 has been significantly increased. Significantly, the upper specific capacitance of 384 F g−1 and 423 F g−1 for APC-H800 and APC-C800 electrodes can be achieved at a current density of 1.0 A g−1, what matters more is that two symmetric devices offer superior energy density and desirable cycling stability (no decrease that occurs after 10,000 cycles) are successfully assembled by employing APC-H800 and APC-C800 electrodes, respectively. More significantly, desirable energy density about 11.18 Wh kg−1 and 12.5 Wh kg−1 at 249.98 W kg−1 and 250 W kg−1 have been achieved for the symmetric supercapacitor devices of APC-H800//APC-H800 and APC-C800//APC-C800. These modification strategies shed insight into the sensible design of a further stage of advanced art carbon electrodes for powerful performance supercapacitors.

Sanitizers Used for Fungal Spoilage Control in Dry-Fermented Cured Meat Production

Contamination caused by fungi stands out as a significant microbiological issue in the food industry, particularly leading to premature spoilage across various food segments, including the dry-fermented meat industry. The emergence of undesired fungi on product surfaces results in substantial economic losses. Once microorganisms infiltrate the food, contamination ensues, and their subsequent proliferation can adversely impact the product’s appearance, odor, flavor, and texture. This, in turn, leads to consumer rejection and negatively affects the commercial brand. Additionally, concerns persist regarding the potential presence of mycotoxins in these products. Given the detrimental effects of spoilage fungi in the food industry, practices such as thorough cleaning and sanitization become crucial to prevent contamination and subsequent premature deterioration. These measures play a pivotal role in ensuring the quality and safety of food, while also extending the shelf life of products. This review delves into the advantages, disadvantages, and factors that may influence the efficacy of commonly used sanitizers in the dry-fermented cured meat industry, including substances like sodium hypochlorite, peracetic acid, and benzalkonium chloride.

Bio-based, closed-loop chemical recyclable aromatic polyamide from 2,5-furandicarboxylic acid: Synthesis, high performances, and degradation mechanism

The resource and environmental challenges posed by the extensive use and disposal of plastics have increased the urgency of research into plastic recycling and the hunt for bio-based alternative feedstocks. As one of the five general engineering polymers, polyamide has not yet been systematically explored in terms of its recycling performance or mechanism, especially aromatic polyamides. In addition, research on novel structured bio-based aromatic polyamides has not received sufficient attention due to the harsh polymerization conditions. In this work, bio-based fully aromatic polyamides based on 2,5-furandicarboxylic acid (FDCA) was successfully synthesized through the acyl chloride method, exhibiting thermal, mechanical, and barrier properties comparable to or superior to those of fossil derived isophthalic acid based polyamides. Moreover, both synthesized polyamides could be hydrolyzed in alkaline environments through the cleavage of amide bonds, as demonstrated by molecular dynamics simulations. The presence of furan rings lowered the energy barrier of hydrolysis as compared to benzene rings. Furthermore, a simple and efficient acidification followed by filtration approach with high recovery yields was developed to recover initial monomers from degradation solutions, thus achieving closed-loop chemical recovery of two polyamides. This work will further expand the application of bio-based feedstock, FDCA, and open new avenues for polyamide recycling research.