Acrylonitrile-based copolymers were synthesized via emulsion and suspension polymerization using hydroxypropyl methacrylate (HPMA) and methyl methacrylate (MMA) as comonomers. The influence of polymerization route and comonomer composition on molecular architecture, thermal behavior, and mechanical performance was systematically investigated. Structural characterization was performed by FT-IR and 1H NMR spectroscopy, confirming successful comonomer incorporation and consistency between feed and copolymer compositions. Molecular weight distribution was determined by gel permeation chromatography (GPC), while thermal properties were evaluated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Intrinsic viscosity measurements were additionally conducted to assess solution behavior and processability. Thermal analyses revealed composition-dependent glass transition behavior and thermal stability, whereas single-fiber tensile testing demonstrated a tunable strength-ductility balance governed by comonomer type and composition. The comparative analysis of emulsion and suspension polymerization highlights the critical role of polymerization route in governing molecular architecture, thermal behavior, and mechanical performance. These findings establish clear structure-process-property relationships in acrylonitrile-based copolymers and provide insight into the rational design of PAN-based functional materials for advanced applications.
Metals are crucial to the functioning of all living organisms, as they are involved in key processes such as catalysis, metabolism, and signaling. Copper is one of these metals that can cause health issues in living organisms when it accumulates excessively in the environment. This overaccumulation often results from industrial mishandling and the natural abundance of copper. To address these problems, we developed a colorimetric probe based on polynorbornene-derived paper strips (PNRh) that rapidly detects copper(II) ions with high selectivity and sensitivity. PNRh shows a prominent color change from colorless to pink in the presence of copper(II) ions and a red-shifted absorption maximum at 560 nm. The limit of detection (LOD) is 80 nM, due to the formation of a ligand-to-metal charge transfer (LMCT) complex between PNRh and copper ions. To improve practical use, we developed paper strips coated with PNRh for the immediate detection of copper(II) ions in field settings. To our knowledge, PNRh is an economical, highly selective, sensitive, and paper strip-based colorimetric sensor for in-field copper ion detection.
Injectable hydrogels have been extensively studied as localized drug-delivery vehicles owing to their high water-content, easy and noninvasive nature of delivery and soft tissue mimicking ability. PEG-based polyethers have been widely used in such applications commercially, over the years. However, the limitations in tunability and stability of PEG systems have been a challenge. In contrast, poly(allyl glycidyl ethers), (PAGE) have emerged as versatile polymer scaffolds due to their biocompatibility and ease of functionalisation. In this work, we have developed a novel PAGE-PEG based hydrogel system via thiol-ene click chemistry. The thiol modification of PEG crosslinkers was made by conjugation of PEG with alpha-Lipoic acid, which provides a stable in-situ generating free thiol source with easy handling and improved biocompatibility. The resulting hydrogels exhibited rapid gelation under UV irradiation and demonstrated significant swelling and rheological properties governed by the network architecture. The thermal and morphological properties of the hydrogels showed promising results for biomedical applications. Importantly, the appreciable shear-thinning and injectable behavior along with substantial pH-responsive cargo release property, offer a promising adaptive platform, suitable for sustainable biomedical and drug-delivery applications. [GRAPHICS]
The synthesis, phase behavior, and semiconductor properties of two new comb-shaped polymers, PMS-C11-BTBT-C8 and PMA-C11-BTBT-C8, containing dialkyl-substituted [1]benzothieno[3,2-b]benzothiophene (BTBT) moieties attached to polymethylsiloxane and methacrylate backbones, respectively, are described. The polymers were synthesized by sequential modification of the BTBT core with carbonyl-containing functional alkyl substituents using the Friedel-Crafts reaction, followed by reduction of the keto group. The target polymers were prepared by two different methods: PMS-C11-BTBT-C8via a hydrosilylation polymer analogous reaction and PMA-C11-BTBT-C8via a radical polymerization reaction. The chemical structure of the polymers obtained was confirmed by 1H,13C, and 29Si NMR spectroscopy and elemental analysis. Their phase behavior was investigated using differential scanning calorimetry and X-ray diffraction analysis. Electrical properties of the polymers synthesized were tested in OFETs with thin films of PMS-C11-BTBT-C8 or PMA-C11-BTBT-C8 as the semiconductor layer. The siloxane polymer exhibited p-type semiconducting properties with the saturated hole mobility up to 2.2 & times; 10-4 cm2V-1s-1. In contrast, the methacrylate polymer exhibited no semiconductor properties in organic field-effect transistors, which may be explained by the rigidity of the polymer backbone limiting crystallization of the BTBT fragments.
Thiol-ene covalent adaptable networks incorporating dual dynamic covalent bonds were designed to clarify the influence of bond composition on thermal, mechanical, and self-healing properties. A vanillin-derived diallyl monomer containing both imine and boronic ester linkages (BE2AV) and an imine-only diallyl monomer (JA2AV) were copolymerized with multifunctional allyl and thiol crosslinkers to form BJAS networks with tunable compositions. For comparison, ABS networks containing only boronic ester linkages were prepared. Swelling measurements indicated an increase in effective crosslink density with increasing tetrafunctional crosslinker content. Dynamic mechanical analysis revealed non-monotonic variations in elastically effective crosslink density, reflecting competing effects of chemical crosslinks and segmental rigidity. The BJAS networks exhibited higher glass transition temperature, tensile modulus, and tensile strength than the ABS networks. Self-healing experiments demonstrated significantly higher healing efficiencies for the BJAS networks (up to 63% after treatment at 80 degrees C for 24 h), compared to the ABS networks (36%), with imine content playing a more pronounced role than boronic ester content in mechanical recovery.
This study investigated the use of carboxylated graphene oxide (GO-COOH) and sulfonated polyetheretherketone (SPEEK) to modify PMIA nanofiltration membranes synergistically for the removal of heavy metal ions from wastewater, and systematically investigated for five heavy metal ions, As(V), Cr(VI), Cd2+, Pb2+ and Zn2+.FTIR analysis reveals that carboxyl groups of GO-COOH and sulfonic acid groups of SPEEK are present on the membrane surface, and the spectral data are suggestive of hydrogen bonding interactions between them. Contact angle testing revealed that the composite film significant increase in hydrophilicity. The PGS membrane achieves water flux of 149.3 L/m2/h at 0.8 MPa and exhibits the rejection over 95% for five heavy metals and all higher than PG and PMIA membranes. Mechanistic analysis indicates that the high negative charge density on the membrane surface enables efficient retention of heavy metal ions through the Donnan effect. Anti-fouling performance tests show that the PGS membrane has excellent anti-fouling properties against bovine serum albumin (BSA), with a flux recovery rate of over 99%. This study confirms that simultaneously enhancing the permeability, selectivity, and fouling resistance of PMIA membranes through the synergistic modification of GO-COOH and SPEEK provides a theoretical basis for developing high-performance heavy metal removal membranes.
In this study, bio-derived methyl salicylate (MES) and 1,4-bis(chloromethyl)benzene were transformed via Williamson etherification into a rigid phenyl diester monomer (PMBD). PMBD was subsequently melt-copolymerized with 1,4-cyclohexanedimethanol (CHDM) and either 1,5-pentanediol (C5) or 1,9-nonanediol (C9) to afford rigid-flexible copolyesters (PCP and PCN). Both copolyesters exhibited moderate molecular weights (M-w = 4.06-4.63 & times; 104 g/mol), with excellent melt processability and compatibility for thin-film printing. FTIR and H-1 NMR analysis confirmed incorporation of PMBD-CHDM aromatic blocks and flexible aliphatic (C5 or C9) segments, enabling systematic tuning and control of the thermomechanical performance. The shorter C5 in PCP led to higher T-g (86.5 degrees C), T-m (197.8 degrees C), and T-d,T-5% (336 degrees C), whereas PCN, containing the more flexible C9, exhibited lower T-g (61.8 degrees C) and T-m (176.7 degrees C) but higher yield strength (65 MPa vs 54 MPa) and elongation at break (304% vs 251%), revealing structure-property relationship similar to poly(ethylene terephthalate)(PET). Soil-burial tests over 30 wk showed modest yet measurable mass losses (3.5% for PCP, 4.4% for PCN), while PET remained inert, with low ecotoxicity (>80% survival at 1-30 mg/kg). PMBD-based copolyesters thus serve as promising sustainable engineering plastics with potential for applications in replaceable humanoid skin and related mechatronic interfaces. [GRAPHICS]
