Strong Antimicrobial Activity of Highly Stable Nanocomposite Containing AgNPs Based on Water-Soluble Triazole-Sulfonate Copolymer

A new hydrophilic polymeric nanocomposite containing AgNPs was synthesized by chemical reduction of metal ions in an aqueous medium in the presence of the copolymer. A new water-soluble copolymer of 1-vinyl-1,2,4-triazole and vinylsulfonic acid sodium salt (poly(VT-co-Na-VSA)) was obtained by free-radical copolymerization and was used as a stabilizing precursor agent. The structural, dimensional, and morphological properties of the nanocomposite were studied by UV–Vis, FTIR, X-ray diffraction, atomic absorption, transmission and scanning electron microscopy, dynamic and electrophoretic light scattering, gel permeation chromatography, thermogravimetric analysis, and differential scanning calorimetry. Hydrodynamic diameter of macroclubs for the copolymer was 171 nm, and for the nanocomposite it was 694 nm. Zeta potential for the copolymer was −63.8 mV, and for the nanocomposite it was −70.4 mV. The nanocomposite had strong antimicrobial activity towards Gram-negative and Gram-positive microorganisms: MIC and MBC values were in the range of 0.25–4.0 and 0.5–8.0 μg/mL, respectively.

Reactivity of 2,3-Dichloropropene in free-radical copolymerization reactions

The copolymers of 2,3-Dichloropropene with vinyl chloride, methyl methacrylate, and styrene of different compositions were obtained via free-radical copolymerization. The copolymerization constants for the comonomers were found from the dependence of the copolymer composition on the initial mixture content. An increase in the content of 2,3-Dichloropropene in the initial mixture was found to decrease the yield and intrinsic viscosity of the copolymer for all systems. The reactivity of 2,3-Dichloropropene in copolymerization reactions was assessed according to the reciprocals of the copolymerization constants of vinyl chloride, methyl methacrylate, and styrene, which indicate the reactivity of the dichlorinated monomer when interacting with comonomer radicals. It was found that 2,3-dichloropropene is the most active in the reaction with a styrene radical. However, its reactivity with a methyl methacrylate radical decreases by a factor of 0.88 as compared to the styrene radical. The lowest reactivity of 2,3-Dichloropropene is observed when interacting with a vinyl chloride radical. The synthesized copolymers can be further modified by replacing chlorine atoms with functional groups.

Determining the Q-e values of polymer radicals and monomers separately through the derivation of an intrinsic Q-e scheme for radical copolymerization

Herein, we describe the first non-arbitrary determination of the Q-e values for individual polymer radicals and monomers. For this purpose, two reference monomers were subjected to a Q-e scheme, which...

MB Dye Adsorption Behavior on Poly (N cyclohexylacrylamide-co-Acrylamide/Maleicacid)/ OMMT Nanocomposite Hydrogels

A series of poly (N-cyclohexylacrylamide-co-Acrylamide/Maleic acid) /OMMT nanocomposite hydrogels (NC) were prepared from free-radical copolymerization in water/methanol medium using ammonium persulfate (APS) as a free radical initiator and N,N’- methylene-bis-acryl amide(MBA) as the cross-linker at 60˚C. The nanocomposite hydrogels were synthesized via in situ polymerization using organo modified MMT (O-MMT) nano clay. The optimum swelling of nanocomposite superabsorbents was achieved at 0.150g of OMMT nanoclay. The synthesized nanocomposites were characterized by FTIR, SEM, XRD and TGA techniques. Swelling and diffusion parameters in water and dye solution were calculated. The effect of two cationic salt solutions on the swelling was studied. The hydrogel nanocomposites showed up to 99.9% removal efficiency towards methylene blue dye adsorption study.

PREPARATION AND STUDY OF THE PROPERTIES OF THE COPOLYMER OF CYCLIC UNSATURATED BISMALEIMIDE WITH STYRENE

The paper is devoted to the study of regularities of radical copolymerization reactions of unsaturated cyclic N,N'-bisimides (M1) with styrene (M2), the study of dependence of copolymerization reaction rate, composition of obtained copolymers, composition and estimated molecular weight on the composition of the initial monomer mixture. With the increase of bismaleimide amount in the initial monomer mixture a decrease of copolymerization reaction yield and molecular weight of the obtained copolymers was observed. This fact can be explained by active participation of bismaleimide in chain transfer in radical copolymerization reaction. The composition of the obtained copolymers in all cases is rich in styrene links

Selective Aerobic Oxidation of P-Methoxytoluene by Co(II)-Promoted NHPI Incorporated into Cross-Linked Copolymer Structure

A wide series of copolymer materials with various contents of 4-vinyl-diisopropyl-phtalate ester (10–90 mol%), divinylbenzene (1–11 mol%) and styrene, as monomers, were obtained by radical copolymerization. In the last steps of the synthesis, diisopropyl ester functionalities were converted into the form of N-hydroxyphthalimide (NHPI) rings. The obtained materials with the NHPI groups immobilized in the copolymer structure were studied by various physicochemical techniques, including FT-IR, UV-Vis-DR, XPS, elemental analysis, and tested as catalysts in aerobic oxidation of p-methoxytoluene in the presence of Co(II) acetate co-catalyst. Conversion of the aromatic substrate was correlated with the NHPI content and cross-linking degree. The best catalytic performance (conversions higher than 23%) was achieved for the copolymer catalysts containing 60% and 30% of 4-vinyl-diisopropyl-phtalate ester. At too high concentrations of NHPI and DVB, some of the NHPI groups were transformed into inactive (C=O)-N=O species or not available due to embedding inside the copolymer structure. The mechanism of the process involving both NHPI centers, forming phthalimide N-oxyl (PINO) radicals, and Co(II) cations was discussed. Stability of the developed catalysts was also tested. The opening of imide rings took place during the catalytic process, resulting in the formation of carboxyl groups and the release of hydroxylamine molecules. The deactivated catalyst could be easily regenerated by repeating two last steps of closing imide ring.

Regularities of the radical copolymerization of dodecyl (meth) acrylate and a new cationic monomer N-(dibutylaminomethyl) methacrylamide

The regularities of radical copolymerization of dodecyl methacrylate (DMA) or dodecyl acrylate (DA) with a new cationic monomer - N-(dibutylaminomethyl) methacrylamide (DBAMMA) in toluene solutions were determined. The copolymers formed at low conversions in the DMA-DBAMMA system are enriched in ether units, and in the DA-DBAMMA system - in aminoamide units. The relative activities of comonomers determined by the Feineman-Ross and Kehlen-Tudosh methods in the first case were 1.56-1.60 (DMA) and 0.87-0.89 (DBAMMA), in the second case - 0.53-0.64 (DA) and 0.80-0.90 (DBAMMA).

Mesoporous Networks of N-Vinylpyrrolidone with (di)Methacrylates as Precursors of Ecological Molecular Imprinted Polymers

Mesoporous polymer networks were prepared via the cross-linking radical copolymerization of non-toxic hydrophilic N-vinylpyrrolidone (VP) with triethylene glycol dimethacrylate (TEGDM) and poly(ethylene glycol) methyl ester methacrylate (PEGMMA) in bulk, using appropriate soluble and thermodynamically compatible macromolecular additives with a branched structure as porogens. The branched copolymers of various monomer compositions were obtained by radical copolymerization in toluene, controlled by 1-decanethiol, and these materials were characterized by a wide set of physical chemical methods. The specific surface areas and surface morphology of the polymer networks were determined by nitrogen low-temperature adsorption or Rose Bengal (RB) sorption, depending on the copolymer compositions and scanning electron microscopy. The electrochemical properties of RB before and after its encapsulation into a branched VP copolymer were studied on a glassy carbon electrode and the interaction between these substances was observed. Quantum chemical modeling of RB-VP or RB-copolymer complexes has been carried out and sufficiently strong hydrogen bonds were found in these systems. The experimental and modeling data demonstrate the high potency of such mesoporous polymer networks as precursors of molecularly imprinted polymers for the recognition of fluorescent dyes as nanomarkers for biomedical practice.

BSA Adsorption and Antibiofilm Properties of (N-Cyclohexylacrylamide-co-Acrylamide/AMPSNa) Hydrogels

The hydrogels poly (N-cyclohexylacrylamide-co-acrylamide/2-acrylamido-2-methyl-1-propanesodiumsulfonate) i.e.poly(NCA-co-AM/AMPSNa) (HG41,HG42,HG43&HG44) were synthesised via free-radical copolymerization of NCA and (AM) in a fixed proportion (50:50), but varying the ionic monomer-AMPSNa (0.1g,0.3g,0.5 d 0.7g) in a medium of mixture of water and methanol at 60°C in an oil bath, Potassium persulfate (KPS) was used as an initiator, while N,N'-methylene-bisacrylamide (MBA) was used as a cross-linker. FT-IR spectral data, SEM, XRD, and TGA techniques were used to characterise the synthesised hydrogel (HG43). On changing pH(3.0, 5.0, 7.0 & 9.0), the amount of Bovine Serum Albumin (BSA) adsorption efficiency by these hydrogels was evaluated. At pH 5.0, which is near to BSA's isoelectric point (4.7)., the maximum adsorption was found. BSA adsorption increased as the amount of AMPSNa increased. SEM and XRD were used to examine the BSA-adsorbed hydrogel (HG43). The antibiofilm abilities of the hydrogel (HG43) by Microtiter plate Assay(MTP), Fluorescence microscopy and SEMl against Staphylococcus aureus and Pseudomonas aureginosa displayed outstanding efficacy.