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Composite film samples of polylactide-natural rubber with a rubber content of 5, 10, and 15 wt % were obtained by the solution method. The study of their morphology shows the presence of rubber inclusions in the form of drops in the polylactide matrix. The thermophysical characteristics are determined by differential scanning calorimetry (DSC). It is determined that when rubber is added and the peak of cold crystallization of polylactide (PLA) disappears on the melting thermograms, the melting temperature decreases by 1–4°C compared to 100% PLA. The structure of the obtained compositions is studied by nuclear magnetic resonance, electron paramagnetic resonance (EPR), and X-ray diffraction. The diffraction patterns of the samples contain reflections characteristic of the crystalline α-form of PLA. [ABSTRACT FROM AUTHOR]

Abstract Objective Papaver decaisnei Hochst. & Steud. Ex Elkan and Papaver glaucum Boiss. & Hausskn. growing wild in Northern Iraq have been historically used for medicinal purposes. In this study, both species were evaluated for their alkaloid content and antimicrobial activities. Results Alkaloids were extracted and isolated by preparative thin-layer chromatography (TLC). Identification was carried out by comparing spectral data (UV and 1H-NMR) and TLC Rf values with those of authentic samples. Two alkaloids, proapaorphine-type mecambrine and aporphine-type roemerine were isolated from P. decaisnei. Two benzylisoquinoline type alkaloids papaverine (major alkaloid) and palaudine as well as aporphine-type N-methylasimilobine have been obtained in P. glaucum. Both P. glaucum and P. decaisnei extracts revealed strong antimicrobial activity on Pseudomonas aeruginosa ATCC 27853 and Enterococcus faecalis ATCC 29212. Collectively these results indicate that P. glaucum and P. decaisnei are promising sources of alkaloids that could further be investigated for medicinal purposes.

Objective: Papaver decaisnei Hochst. & Steud. Ex Elkan and Papaver glaucum Boiss. & Hausskn. growing wild in Northern Iraq have been historically used for medicinal purposes. In this study, both species were evaluated for their alkaloid content and antimicrobial activities. Results: Alkaloids were extracted and isolated by preparative thin-layer chromatography (TLC). Identification was carried out by comparing spectral data (UV and 1H-NMR) and TLC Rf values with those of authentic samples. Two alkaloids, proapaorphine-type mecambrine and aporphine-type roemerine were isolated from P. decaisnei. Two benzylisoquinoline type alkaloids papaverine (major alkaloid) and palaudine as well as aporphine-type N-methylasimilobine have been obtained in P. glaucum. Both P. glaucum and P. decaisnei extracts revealed strong antimicrobial activity on Pseudomonas aeruginosa ATCC 27853 and Enterococcus faecalis ATCC 29212. Collectively these results indicate that P. glaucum and P. decaisnei are promising sources of alkaloids that could further be investigated for medicinal purposes. [ABSTRACT FROM AUTHOR]

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The structures of the mono- and the dihalogenated N-unsubstituted 2-aminobenzamides were characterized by means of the spectroscopic (1H-NMR, UV-Vis, FT-IR, and FT-Raman) and X-ray crystallographic techniques complemented with a density functional theory (DFT) method. The hindered rotation of the C(O)-NH2 single bond resulted in non-equivalence of the amide protons and therefore two distinct resonances of different chemical shift values in the ¹H-NMR spectra of these compounds were observed. 2-Amino-5-bromobenzamide (ABB) as a model confirmed the presence of strong intramolecular hydrogen bonds between oxygen and the amine hydrogen. However, intramolecular hydrogen bonding between the carbonyl oxygen and the amine protons was not observed in the solution phase due to a rapid exchange of these two protons with the solvent and fast rotation of the Ar-NH2 single bond. XRD also revealed the ability of the amide unit of these compounds to function as a hydrogen bond donor and acceptor simultaneously to form strong intermolecular hydrogen bonding between oxygen of one molecule and the NH moiety of the amine or amide group of the other molecule and between the amine nitrogen and the amide hydrogen of different molecules. DFT calculations using the B3LYP/6-311++G(d,p) basis set revealed that the conformer (A) with oxygen and 2-amine on the same side predominates possibly due to the formation of a six-membered intramolecular ring, which is assisted by hydrogen bonding as observed in the single crystal XRD structure. [ABSTRACT FROM AUTHOR]

Two new Schiff bases containing olefinic linkages have been synthesized by condensing aliphatic diamines with dicinnamoylmethane under specified conditions. The existence of these compounds predominantly in the intramolecularly hydrogen bonded keto-enamine form was well demonstrated by their IR, 1H-NMR and mass spectral data. Dibasic tetradentate N2O2 coordination of the compounds in their [ML] complexes (M = Ni(II), Cu(II) and Zn(II)) was established on the basis of analytical and spectral data.

Phenylazo- and thiazolylazo-2,4-pentanediones on reaction with 2-aminophenol and 2-aminothiophenol yielded a new series of polydentate Schiff’s base ligands. The structure and tautomeric nature of these compounds and their metal complexes were established on the basis of their IR, 1H-NMR and mass spectral data. The spectral and analytical data revealed the condensation of both carbonyl groups of 3-(2-thiazolylazo)- 2,4-pentanedione with 2-aminophenol to form an N2O2 tetradentate ligand. Details on the formation of its [ML] complexes with Ni(II), Cu(II) and Zn(II) and the nature of their bonding are discussed based on analytical, IR, 1H-NMR and mass spectral data.

Phenylazo- and thiazolylazo-2,4-pentanediones on reaction with 2-aminophenol and 2-aminothiophenol yielded a new series of polydentate Schiff’s base ligands. The structure and tautomeric nature of these compounds and their metal complexes were established on the basis of their IR, 1H-NMR and mass spectral data. The spectral and analytical data revealed the condensation of both carbonyl groups of 3-(2-thiazolylazo)- 2,4-pentanedione with 2-aminophenol to form an N2O2 tetradentate ligand. Details on the formation of its [ML] complexes with Ni(II), Cu(II) and Zn(II) and the nature of their bonding are discussed based on analytical, IR, 1H-NMR and mass spectral data.

The structures of the mono- and the dihalogenated N-unsubstituted 2-aminobenzamides were characterized by means of the spectroscopic (1H-NMR, UV-Vis, FT-IR, and FT-Raman) and X-ray crystallographic techniques complemented with a density functional theory (DFT) method. The hindered rotation of the C(O)–NH2 single bond resulted in non-equivalence of the amide protons and therefore two distinct resonances of different chemical shift values in the 1H-NMR spectra of these compounds were observed. 2-Amino-5-bromobenzamide (ABB) as a model confirmed the presence of strong intramolecular hydrogen bonds between oxygen and the amine hydrogen. However, intramolecular hydrogen bonding between the carbonyl oxygen and the amine protons was not observed in the solution phase due to a rapid exchange of these two protons with the solvent and fast rotation of the Ar–NH2 single bond. XRD also revealed the ability of the amide unit of these compounds to function as a hydrogen bond donor and acceptor simultaneously to form strong intermolecular hydrogen bonding between oxygen of one molecule and the NH moiety of the amine or amide group of the other molecule and between the amine nitrogen and the amide hydrogen of different molecules. DFT calculations using the B3LYP/6-311++G(d,p) basis set revealed that the conformer (A) with oxygen and 2-amine on the same side predominates possibly due to the formation of a six-membered intramolecular ring, which is assisted by hydrogen bonding as observed in the single crystal XRD structure.

Trident molecules containing pyridyl groups have been prepared for use as novel extraction reagents to investigate their physicochemical properties for dissolution into the aqueous phase and their ability, together with their corresponding monomeric analogues, to extract precious metal ions. Differences in their behavior were related to the pK a values of the trident molecules and the position of the nitrogen atom in the pyridyl groups. The trident molecules exhibit the ability to selectively extract silver from mixtures of other precious metals. The extraction mechanism and the coordination site of the silver ion with a 2-pyridyl derivative were determined by slope analysis and peak shift of the 1H-NMR spectra of the extraction reagent before and after silver loading. [ABSTRACT FROM PUBLISHER]

Transition metal complexes of Mn(II), Fe(III), Cr(III) and Zn(II) metal ions with a general formulas [Mn(L)2(Cl)2]·4H2O ( I), [Fe(L)2(Cl)2]·Cl·6H2O ( II), [Cr(L)2(Cl)2]·Cl·6H2O ( III) and [Zn(L)2(Cl)2]·2H2O ( IV) where L = 4-acetylpyridine thiosemicarbazone, have been synthesized and interpreted using CHN elemental analysis, magnetic susceptibility measurements, molar conductance, thermal analysis and spectroscopic techniques; i.e., infrared, electronic UV/vis, 1H-NMR and mass. The manganese(II), ferric(III), chromium(III) and zinc(II) complexes have octahedral geometry. The molar conductance measurements reveal that the Mn(II) and Zn(II) chelates are non-electrolytes but Fe(III) and Cr(III) have an electrolytic behavior. The IR spectra show that the 4-acetylpyridine thiosemicarbazone free ligand is coordinated to the metal(II) chlorides as a neutral bidentate ligand through both of the lone pair of electrons of the C=N azomethine group and C=S group. X-ray powder diffraction gives an impression that the resulting complexes are amorphous and different from the start materials. The thermogravimetric studies indicate that uncoordinated water molecules are lost in the first and second decomposition steps. The activation thermodynamic parameters E*, ΔH*, ΔS* and ΔG* are estimated from the differential thermogravimetric analysis (DTG) curves using Horowitz–Metzger (HM) and Coats–Redfern (CR) methods. The ligand and its complexes have been screened for antibacterial and antifungal activities against two bacteria; i.e., Escherichia coli (Gram −ve) and Bacillus subtilis (Gram +ve) and two fungi, i.e., tricoderma and penicillium activities). [ABSTRACT FROM AUTHOR]

New methacrylic monomer having free radical polymerizable methacryloyl group and photocrosslinkable functional group was synthesized by reacting hydroxyl chalcone with methacryloyl chloride. The monomer was homopolymerized in methyl ethyl ketone solvent using benzoyl peroxide as an initiator at 70°C. The prepared homopolymer was characterized by UV, FT-IR, 1H-NMR and 13C-NMR spectra. The molecular weights (Mw and Mn) were estimated by gel permeation chromatography. The thermal stability of the polymer was measured by thermogravimetric analysis. The glass transition temperature of the polymer was determined by differential scanning calorimetry. The photocrosslinking property of the polymer was also studied. [ABSTRACT FROM AUTHOR]

The new functional methacrylic monomer, 4-benzyloxycarbonylphenyl methacrylate (BCPM) was synthesized by reacting benzyl-4-hydroxybenzoate dissolved in ethyl methyl ketone (EMK) with methacryloyl chloride in the presence of triethylamine. The copolymers from different feed compositions of BCPM and glycidyl methacrylate (GMA) were synthesized by free radical polymerization in EMK solution at 70±1 °C, using benzoyl peroxide as an initiator. The copolymers were characterized by FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques. The polydispersity indices of the polymers determined using gel permeation chromatography suggest a strong tendency for chain termination by disproportionation. The glass transition temperature of the copolymers was found to increase with increase in mole fraction of BCPM in the copolymer. Thermogravimetric analysis of the copolymers performed in air revealed that the thermal stability increases with increase in BCPM content in the copolymer. The solubility of the polymers was tested in various polar and non-polar solvents. Copolymer compositions were determined using 1H-NMR spectra. The monomer reactivity ratios were determined by the application of conventional linearisation methods such as Fineman–Ross, Kelen–Tu¨do¨s and extended Kelen–Tu¨do¨s and a nonlinear error invariable model method using a computer program RREVM. The adhesives based on poly(BCPM-co-GMA) were prepared for application on leather and their peel strengths were determined at 50 and 70 °C. [Copyright &y& Elsevier]

The acrylic monomer, 3,5-dimethylphenyl methacrylate was synthesized by reacting 3,5-dimethylphenol dissolved in ethyl methyl ketone (EMK) with methacryloyl chloride in the presence of triethylamine. The homopolymer and various copolymers with glycidyl methacrylate were synthesized using free radical polymerization in EMK solution at 70±1 °C using benzoyl peroxide as initiator. The copolymers were characterized by FT-IR, 1H-NMR and 13C-NMR techniques. The molecular weights (Mn and Mw) and polydispersity indices were determined using gel permeation chromatography. The glass transition temperatures were determined by differential scanning calorimetry. Thermogravimetric analysis were performed in air. The solubilities of the polymers were tested in various polar and non-polar solvents. Copolymer compositions were determined using 1H-NMR spectra. The monomer reactivity ratios were determined by application of conventional linearisation methods such as Fineman–Ross, Kelen–Tüdös and extended Kelen–Tüdös. [Copyright &y& Elsevier]

The acrylic monomer, 3,5-dimethylphenyl methacrylate was synthesized by reacting 3,5-dimethylphenol dissolved in ethyl methyl ketone (EMK) with methacryloyl chloride in the presence of triethylamine. Taking six different feed compositions of 3,5-dimethylphenyl methacrylate and methyl methacrylate, the copolymers were synthesized in EMK solution at 70±1°C using benzoyl peroxide as initiator. The copolymers were characterized by FT-IR, 1H-NMR, and 13C-NMR spectroscopic techniques. The solubilities of the polymers were tested in various polar and nonpolar solvents. The elemental analysis was determined by Perkin-Elmer C-H analyzer. The glass transition temperatures of the polymers were determined by differential scanning calorimeter. Thermogravimetric analysis of the polymers were performed in air. Copolymer compositions were determined using 1H-NMR spectra. The monomer reactivity ratios were determined by the application of conventional linearization methods such as Fineman-Ross, Kelen-Tüdös, and extended Kelen-Tüdös, as well as by a nonlinear “error-in-variables” method using a computer program, RREVM. [ABSTRACT FROM AUTHOR]