Elastane is ubiquitous in polyester-based textiles and complicates depolymerization-based recycling because it can undergo thermal degradation and chemical bond cleavage, consuming reagents and forming low-molecular by-products that may compromise monomer quality. Here, we investigate alkaline PET depolymerization of PET/elastane blends under an intentional base-competition scenario in a laboratory kneader. Pure PET (100/0) and PET/EL blends (95/5 and 85/15, wt/wt) were processed under quasi-solid-state conditions at 140 °C for 5 min using solid NaOH dosed at 2.1 mol per mol PET repeat unit and pelletized feedstocks to ensure scale-relevant mixing and reproducible chamber filling. Torque and bulk-temperature profiles were similar across compositions, and isolated terephthalic acid yields remained in a narrow corridor (68-71%), indicating that PET depolymerization is not measurably impaired by 5-15 wt% elastane within this reaction window. Differential scanning calorimetry of water-insoluble residues revealed pronounced changes in elastane-related thermal transitions, evidencing elastane modification during treatment. Targeted 1H NMR screening of recovered TA against a 4,4'-methylenedianiline spiked reference showed no detectable co-isolated aromatic diamines. Overall, the study demonstrates robust monomer recovery from mixed PET/EL textiles under solid-NaOH, short-residence, solvent-lean processing, while identifying residue analytics as the key bottleneck for quantifying elastane fate and closing component balances.

ABSTRACT A novel bis(ether anhydride) incorporating the carbazolyltriphenylamine (CzTPA) segment, specifically 4,4′‐bis(3,4‐dicarboxyphenoxy)‐4″‐(carbazol‐9‐yl)triphenylamine dianhydride, has been synthesized. Following this, polycondensation with commercially available aromatic diamines led to the formation of a series of electroactive aromatic poly(ether imide)s. All synthesized polymers exhibit excellent solubility in polar organic solvents and can be solution‐cast into smooth, flexible thin films. These poly(ether imides) demonstrate glass transition temperatures ( T g ) ranging from 251°C to 260°C, with no significant thermal degradation observed below 500°C, indicating their impressive thermal stability. Cyclic voltammetry (CV) measurements reveal two oxidation waves at approximately 1.20 and 1.51–1.63 V, respectively. The first redox process is quasi‐reversible, while the second is irreversible. In their neutral state, the cast films appear colorless and transparent, transitioning to pale blue during the first oxidation stage and to light Prussian blue in the second oxidation stage. Furthermore, coupling reactions involving the pendant carbazole units readily occur when the polymers are scanned to 1.8 V during CV measurements. Upon oxidation, the polymer films exhibit moderately high absorption in the near‐infrared region.

Conventional ceramic and metallic impact-protective materials are strong yet brittle and heavy, whereas soft materials such as Sylgard 184 and Styrofoam provide limited energy absorption and structural resilience. Achieving high impact resistance together with intrinsic self-healing and recyclability remains a long-standing challenge for polymeric systems, as most high-strength soft elastomers rely on permanent covalent networks that hinder their reprocessability. Taking inspiration from human articular cartilage-a natural impact-dissipative yet non-healable tissue-we developed a supramolecular polyurethane-urea elastomer (PU-BAMB) that emulates its fibrous-matrix architecture by integrating hierarchical hydrogen bonding and π-π stacking interactions through an aromatic diamine chain extender. This molecular design reproduces the multilevel energy-dissipation mechanism of cartilage while overcoming its biological limitation by introducing intrinsic self-healing and recyclability. The cooperative supramolecular framework achieves a finely tuned synergy between elasticity and rigidity, resulting in remarkable tensile strength (21.08 MPa), high fracture energy (138.36 kJ m- 2), and rapid self-healing (97% recovery within 1 h at 90°C). PU-BAMB exhibits pronounced hysteresis, strain-rate-induced stiffening, and outstanding impact-mitigation efficiency while retaining lightweight flexibility and sustainability. This work establishes a bio-inspired yet functionally advanced design paradigm for constructing robust, self-healing, and recyclable impact-resistant elastomers for next-generation protective coatings, damping systems, and adaptive wearable devices.

ABSTRACT A novel series of thermally stable poly(azomethine-ether) polymers (PAZa-d) containing trimethylbenzene moiety were synthesized via polycondensation of a new monomer, with two aliphatic (C2 and C5) diamine and two aromatic (m-phenylene and o-phenylene) diamine. The structural characteristics of the polymers were elucidated using FT-IR, NMR, GPC, SEM, XRD, and TGA. The polymers exhibited high molecular weights (Mw) ranging from 32,600 to 41,600 g mol−1, with PAZc displaying the highest Mw. XRD analysis revealed the amorphous nature of PAZa-c and the crystalline phase of PAZd. SEM micrographs showed sponge-like porous structures for PAZa-c and semi-crystalline particles for PAZd. The polymers demonstrated high thermal stability, with final decomposition temperatures (FDT) ranging from 539.57 to 666.03°C. Antimicrobial screening revealed significant antibacterial activity against Gram-negative bacteria, with PAZc (m-phenylene derivative) exhibiting the highest efficacy. Further investigation of the polymers’ effect on E. coli O157:H7 showed 93–100% growth inhibition. Molecular docking studies using “1JIJ” and “1KNZ” proteins for S. aureus and E. coli, respectively, corroborated the experimental findings, with PAZb and PAZc demonstrating the highest docking scores. The synthesized poly(azomethine-ether) polymers, particularly PAZc, show promise as potential antimicrobial agents for combating Gram-negative bacteria.

Molecular dynamics unveils compatibility between aromatic ester-based liquid crystalline epoxy and diamine curing agent for enhanced intrinsic thermal conductivity

Two amide-preformed aromatic diamine monomers, N,N-bis(4-(3-aminobenzamido)phenyl)-N’,N’-bis(4-methoxyphenyl)-1,4-phenylenediamine (m-6) and N,N-bis(4-(4-aminobenzamido)phenyl)-N’,N’-bis(4-methoxyphenyl)-1,4-phenylenediamine (p-6), were synthesized and utilized to prepare two series of electroactive poly(amide-imide)s (PAIs) through a two-step polycondensation reaction with commercially available aromatic tetracarboxylic dianhydrides. The obtained polymers exhibited solubility in various polar organic solvents, and most of them could form transparent, flexible films via solution casting. Thermal analysis indicated glass transition temperatures (Tg) ranging from 250 °C to 277 °C, as measured by DSC, with no significant weight loss observed before 400 °C in TGA tests. Cyclic voltammograms (CV) of the polymer films on ITO-coated glass substrates revealed two reversible oxidation redox pairs between 0.67 and 1.04 V vs. Ag/AgCl in an electrolyte-containing acetonitrile solution. The PAI films showed stable redox activity with high optical contrast both in the visible and near-infrared regions, transitioning from colorless in the neutral state to green and blue in the oxidized states. Furthermore, the polymer films retained good electrochemical and electrochromic stability even after more than 100 cyclic switching operations. The PAIs displayed outstanding electrochromic performance, including high optical contrast (up to 95%), rapid response times (below 4.6 s for coloring and 5.7 s for bleaching), high coloration efficiency (up to 240 cm2/C), and low decay in optical contrast (less than 5% after 100 switching cycles for most PAIs).

The structure of self-assembled monolayers (SAMs) greatly influences electrochemical interface behavior. This study systematically examines how positional isomers of aromatic diamines (ADMs) assemble on a glassy carbon (GC) electrode and how such ordering affects the attachment and performance of electrochemically reduced graphene oxide (ERGO). SAMs of ortho-, meta-, and para-phenylenediamine (o-PDA, m-PDA, and p-PDA) were fabricated on GC and characterized using atomic force microscopy (AFM) and Raman spectroscopy. Among them, GC/p-PDA exhibited the most compact and homogeneous interfacial structure. ERGO was subsequently immobilized through the free amine functionalities of the SAM, as confirmed by attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV). Strong covalent coupling and electrostatic interactions between the positively charged ERGO and terminal amines enabled stable attachment. Under optimized conditions, the modified GC/p-PDA/ERGO electrode demonstrated exceptional electrocatalytic activity toward nitrobenzene (NBz) reduction, achieving a high sensitivity of 1410 μA mM−1 cm−2 and a low detection limit of 0.040 μM. In addition, this sensor displayed outstanding anti-interference capability, stability, and recovery in a water sample. These results establish GC/p-PDA/ERGO sensor as a robust and efficient electrocatalytically active interface for nitroaromatic pollutants detection and sustainable environmental monitoring.

0D polar BHPs are constructed for self-powered X-ray detection, namely AP 2 BiI 7 . The detector exhibits highly stable X-ray detection performance, benefiting from the anchoring effect of the aromatic diamine cations.

This study emphasises the Synthesis of novel bis-Schiff base derivatives via the condensation reaction of two different aldehydes with a aromatic diamine. This reaction was carried out between p-phenylenediamine with 4-chlorobenzaldehyde and 2,4-dichlorobenzaldehyde. The study will explain the structural comparison between the compound PP4CLB and PP24CLB. The synthetic compounds' configurations were verified by DFT calculations, and their structural integrity was verified by NMR, Raman, and IR spectroscopy. To provide a detailed characterisation of molecular properties, the study included a wide range of analyses, such as the assessment of molecular electrostatic potential, frontier molecular orbitals, and HOMO-LUMO energy gaps. For our molecular docking analysis, we used the Tdp1 catalytic domain in complex with an inhibitor (PDB ID: 6W7J) protein as the target. Both PP4CLB and PP24CLB used the same protein structure. The docking results indicated that PP24CLB demonstrated a marginally superior binding affinity (-8.03kcal/mol) relative to PP4CLB (-7.89kcal/mol). The interaction analysis showed that both ligands made several stabilising connections in the active site of 6W7J. PP24CLB had two hydrogen bonds and other non-covalent interactions. On the other hand, PP4CLB had other non-covalent interactions. The PASS prediction showed that our compound is very likely to have biological activity, with a Pa value of 0.849. This Pa score means that the compound is very likely to work as a Glycosylphosphatidylinositol phospholipase D (GPI-PLD) inhibitor.

ABSTRACTLow‐valency multivalent iminosugars have recently emerged as promising inhibitors of the therapeutically relevant enzyme β‐glucocerebrosidase (GCase). A new synthetic strategy has been developed to simultaneously build more than one trihydroxypiperidine iminosugar unit onto a polyamine scaffold via double reductive amination (DRA) of a d‐mannose derived dialdehyde. Five divalent derivatives, using both aliphatic and aromatic diamines and a trivalent compound based on an aromatic scaffold have been synthesized and evaluated as GCase inhibitors. Only oligomers with an aromatic core (26, 31, and 37) strongly inhibit GCase with IC50 values in the low micromolar range and activity enhancements, when compared to the monovalent counterpart, that confirm the occurrence of a positive multivalent effect. Kinetic analysis for divalent 31 and trivalent 37 revealed a mixed‐type inhibition. To rationalize the unexpected behavior of 37, an integrated biophysical and computational approach based on STD‐NMR, docking, and MD simulations was employed, allowing to clarify the structural basis for its inhibitory profile and paving the way to the rational design of novel inhibitors able to bridge multiple interaction sites of the target enzyme.

Structural isomeric aromatic diamine linkers influenced electrocatalysis of AuNPs: Efficient assessment of hydrazine in environmental water samples

Silicon (Si) has garnered considerable attention as one of the most promising anode materials due to its high theoretical capacity (over 3500 mAh g–1), which is nearly 10 times that of conventional graphite anodes (∼372 mAh g–1). However, the alloying/dealloying mechanism with Li+ causes a drastic volume expansion (>300%) of Si particles, leading to cracks or pulverization of electrodes and the formation of unstable solid electrolyte interphase (SEI) layers. This phenomenon ultimately results in rapid capacity fading and short cycle life, hindering the commercialization of Si-based anodes.To address these challenges, the strategic engineering of binders has arisen as a promising solution to enhance the structural integrity and performance of Si-based anodes. The introduction of cross-linking within the linear framework is regarded as an effective route to withstand the huge volume change of Si particles. By interconnecting polymer chains and creating a three-dimensional (3D) network with heightened mechanical robustness, the stresses caused by the considerable deformation of Si particles can be dissipated or dispersed through a multidimensional network.Our work focuses on the strategic structural design and optimization of 3D cross-linked network binders. It involves tailoring an ideal combination of a polymer framework and a cross-linker through comprehensive evaluation and discernment of the distinctive characteristics of each cross-linker. First, we use poly(vinyl alcohol) grafted poly(acrylic acid) (PVA-g-PAA, abbreviated as PVgA) as the polymer backbone. It not only enhances polymer flexibility to complement the glassy characteristics of PAA but can also be easily and environmental friendly synthesized using water as a solvent. Second, aromatic diamines are employed as cross-linkers to build a robust amide network. The presence of aromatic rings within diamine cross-linkers can provide a combination of high modulus and enhanced adhesion through resonance stabilization. Herein, comparative investigations were carried out on cross-linked PVgA-based binders employing three distinct cross-linkers, namely, 2,2′-bis(trifluoromethyl)benzidine (TFMB), 3,3′-oxydianiline (ODA), and 4,4′-oxybis[3-(trifluoromethyl)aniline] (TFODA). We specifically explore the effectiveness of two functional groups: the trifluoromethyl group (−CF3) and the ether linkage. The presence of the −CF3 groups in the TFMB and TFODA molecules can enhance the polarity strength of the binder, facilitating the formation of dynamic hydrogen bonds with the Si surface. These hydrogen bonds act as sacrificial bonds, capable of breaking to dissipate energy and then reforming during volume changes. The ether linkage between two rigid phenyl groups is well-known for enhancing molecular flexibility by providing a center for rotation, bending, and vibration modes. This molecular freedom presented in the ODA and TFODA molecules is expected to impart flexibility, complementing the inherent rigidity resulting from cross-linking, while enhancing ionic conductivity. It was found that the cross-linked binder with TFODA, incorporating both −CF3 and −O–, showed synergistic effects in establishing a well-balanced 3D framework characterized by heightened elasticity and reinforced binding forces. This led to enhanced electrochemical performances, including improved initial Coulombic efficiency (ICE), rate capability, and cycling stability. Figure 1

Redox-active and electrochromic poly(amide-imide)s derived from Imide ring-preformed dicarboxylic acids and triphenylamine-based aromatic diamines

Abstract A novel diacid monomer, 2,3-Bis-[4′-(4″-carboxymethylene)phenoxyphenylene] (BCPPQ), featuring a rigid cardo-type quinoxaline core and flexible ether-methylene linkages, was synthesized via a two-step process from 4,4′-difluorobenzil. Structural confirmation was achieved through FT-IR, 1 H and 13 C NMR (including DEPT), and HRMS. BCPPQ was then polymerized with various aromatic diamines using triphenyl phosphate in an NMP/pyridine/LiCl system to yield a series of high molecular weight polyamides. These polyamides exhibited excellent solubility in polar aprotic solvents (e.g., DMF, DMAc, NMP) and showed inherent viscosities ranging from 0.16 to 0.25 dL/g. FT-IR analysis confirmed amide bond formation. Thermal studies (TGA/DSC) revealed high thermal stability with decomposition temperatures above 395 °C and glass transition temperatures between 173 and 198 °C. XRD patterns showed broad halos, confirming their amorphous nature. The incorporation of a bulky quinoxaline unit and flexible linkages improved solubility without significantly compromising thermal performance, suggesting their potential for high-performance material applications.

To enhance their physical and thermal properties, telechelic polypeptides with extended peptide chains from aromatic diamines were synthesized via the chemoenzymatic polymerization of diamine-type initiators and amino acid esters. With the introduction of meta-substituted aromatic diamines, atomic force microscopy (AFM) revealed the formation of large aggregates in telechelic polyalanine (TPA), which was attributed to π‒π stacking interactions between aromatic rings, as well as short fibrous aggregates with branched structures. The introduction of rigid aromatic rings also improved the thermal stability of the polypeptides.

Polyimides (PIs),known for high thermal stability, strength,andchemical resistance, are used in energy systems, such as fuel cellsand redox flow batteries. Despite Nafion membranes offering high protonconductivity, their high cost, strong water dependency, and severevanadium ion crossover limit their long-term stability and practicalviability in vanadium redox flow batteries (VRFBs). Thus, designinghigh-performance proton exchange membranes (PEMs) based on PI withboth selective proton conductivity and vanadium ion blocking capabilityhas become a critical challenge. This study presents a design strategythat combines alicyclic and aromatic diamine monomers to achieve bothstructural and performance benefits. The rigid and bulky tricyclodecanediamine (TCDDA) is copolymerized with flexible aromatic diamines (ODA)and sulfonated diamines (BDSA) to synthesize segmented copolymersincorporated into the PI backbone. This design increases the freevolume and enables controlled microphase separation for selectiveproton transport and vanadium blocking. To assess steric effects andchain stacking, a less bulky analogue, noborane diamine (NBDA), wasalso used for comparison. The TCDDA-based membranes exhibited outstandingcomprehensive properties, including a tensile strength of up to 89 MPaand an elongation at break of 22.7%. Microstructural analysis revealedthat TCDDA promoted orderly chain stacking and stable phase separationcompared with the NBDA series, allowing for selective ion transportwithout the need for additional pore-forming treatments. In VRFB tests,the PEM with 10% TCDDA (T10) demonstrated an exceptionally low vanadiumion permeability (9.79 × 10–8 cm2/min), significantly outperforming Nafion and NBDA-based membranesin terms of Coulombic efficiency. Energy efficiency remains above80% across all current densities. The T10 membrane retained its integrityand conductivity after repeated cycles, confirming excellent stability.The remarkably low vanadium ion permeability of TCDDA-based alicyclicPI further underscores its high long-term durability and selectivity.

In the first part of this study, magnetic nanoparticles were decorated with folic acid (Vitamin B9) under ultrasonic agitation in water, resulting in heterogeneous nano-biocatalysts (FA@γ-Fe2O3), which were characterized using different techniques, such as VSM, FT-IR, and FESEM. The efficiency of the as-prepared magnetic nanocatalyst was assessed in the synthesis of quinoxaline derivatives. In the second part, a Cu (II) folic acid complex was used for modifying the surface of γ-Fe2O3 (FA-Cu@γ-Fe2O3). It was used successfully in several different transformations in a one-pot reaction sequence, including the aerobic oxidation of benzylic alcohols to aldehydes and the tandem synthesis of benzimidazoles through the dehydrogenative coupling of primary benzylic alcohols and aromatic diamines. The biocatalysts maintained their efficiency and structural integrity after 4 runs, which confirmed that components are firmly bonded. The advantages of these catalytic systems include easy separation and reusability of the solid catalyst for subsequent rounds of reactions with an external magnet, demonstrating great potential for practical applications.

Sulfur‐containing fused heterocyclic polybenzothiazoles are promising materials with advanced functionalities, yet their synthesis has long been constrained by substrate limitations and scalability challenges. Here, a base‐mediated multicomponent polymerization strategy using readily available elemental sulfur, aromatic diamines, and aromatic dialdehydes is developed to synthesize unprecedented polybenzothiazoles with scalability. By efficient alkaline activation of substrates through nucleophilic sulfurization‐cyclization cascades, this method enables economically viable kilogram‐scale production in a one‐pot process with high yields (73–98%) and monomer universality, including previously incompatible electron‐deficient aromatic amines. The resulting polybenzothiazoles unlock their long‐overlooked potential in precious metal recovery, demonstrating selective, rapid, and efficient extraction (>99%) of gold (Au), palladium (Pd), and platinum (Pt) from ultra‐trace concentrations (1 ppb) to complex matrices including surface water, e‐waste, and spent catalyst leachates. Mechanistic studies reveal that the synergistic nitrogen (N)/sulfur (S) participation and π‐conjugation in their fused heterocycles govern metal coordination selectivity and redox stability. This work establishes a practical yet versatile platform to advance polybenzothiazoles from synthesis to resource utilization, highlighting their transformative role in addressing critical challenges through adaptive material design and precious metal recovery.

To study the influence of curing agent structure on the properties of epoxy resin, four types of aromatic diamines with the structure of diphenyl methane (4,4′-methylenedianiline (MDA), 4,4′-methylenebis(2-ethylaniline) (MOEA), 4,4′-methylenebis(2-chloroaniline) (MOCA), and 4,4′-methylenebis(3-chloro-2,6-diethylaniline) (MCDEA)) and a high-performance epoxy resin, 3-(oxiran-2-ylmethoxy)-N,N-bis(oxiran-2-ylmethyl)aniline (AFG-90MH), were used in this study. The resulting resin systems were designated as AFG-90MH-MDA, AFG-90MH-MOEA, AFG-90MH-MOCA, and AFG-90MH-MCDEA. After curing, these systems were named AFG-90MH-MDA-C, AFG-90MH-MOEA-C, AFG-90MH-MOCA-C, and AFG-90MH-MCDEA-C. The influence of the structure of the diamines on the processability, curing reaction activity, and thermal and mechanical properties (including flexural and tensile properties) of the epoxy resins were investigated. These systems demonstrate excellent processability with wide processing windows ranging from 30 °C to 110–160 °C while maintaining low viscosity. Consistent apparent activation energy (Ea) trends via both Kissinger and Flynn-Wall-Ozawa methods were observed. The epoxy systems exhibit the following increasing Ea sequence: AFG-90MH-MDA < AFG-90MH-MOEA < AFG-90MH-MOCA < AFG-90MH-MCDEA. The processability and curing reaction kinetic results indicate that the reactivities of the diamines decrease in the order: MDA > MOEA > MOCA > MCDEA. Polar chlorine substituents in diamines strengthen intermolecular interactions, thereby enhancing mechanical performance. The flexural strength of cured epoxy systems decreases as follows with corresponding values: AFG-90MH-MOCA-C (165 MPa) > AFG-90MH-MDA-C (158 MPa) > AFG-90MH-MCDEA-C (148 MPa) > AFG-90MH-MOEA-C (136 MPa). Diamines with substituents like chlorine or ethyl groups reduce the glass transition temperatures (Tg) of the cured resin systems. However, the cured resin systems with the diamines containing chlorine demonstrate superior thermal performance compared to those with ethyl groups. The cured epoxy systems exhibit the following descending glass transition temperature order with corresponding values: AFG-90MH-MDA-C (213 °C) > AFG-90MH-MOCA-C (190 °C) > AFG-90MH-MCDEA-C (183 °C) > AFG-90MH-MOEA-C (172 °C).

The 2015-2016 National Health and Nutrition Examination Survey (NHANES) included biomonitoring of aromatic diamines obtained after acid hydrolysis of urine samples for the first time. Aromatic diamines in hydrolyzed urine are biomarkers that are not unique to a single substance. Without further information, that renders association with potential exposures very difficult. This review provides an overview of potential sources of urinary aromatic diamines, the most important being aromatic diisocyanates (occupational and home-use), aromatic diamines themselves (predominantly from hair dye products), and polyurethanes (medical devices and implants). Expected urinary diamine concentrations from these and other sources as well as background levels are evaluated based on available literature data. Finally, recommendations are made to improve the value of future data collections. These include analytical enhancements, better mapping of potential sources of the biomarkers prior to conducting the survey, and documentation of product use to enable identification of exposure sources. These improvements are indispensable for investigating potential links with medical conditions should this be envisioned.