75 research outputs found

    Morphological and Biochemical Characteristics of Wild Loquat (Eriobotrya japonica Lindl.) Genotypes in Turkey

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    This study was carried out to determine the pomological and biochemical characteristics of eight different loquat genotypes collected from the Black Sea region (Turkey) in 2018. Totally 20 fruits, at the same ripening stage, were collected from the selected genotypes and tested. Results suggested that there were a high (0.768-0.907) positive and statistically significant correlations among all pomological features (P 0.05). According to the PCA (principal component analysis) analysis of the pomological characteristics, the genotype #1 was superior as compared with other genotypes. Contrary to the pomological characteristics, genotype #1 was found to have the lowest phenolic compounds and it was also moderate in sugar content but a high-grade genotype by organic acids, especially citric acid and malic acid. Furthermore, results suggested that genotypes #3, #4, #7 and #8 were identical and were rich in glucose, succinic acid, and total flavonoid. The results suggested that loquat fruits had a high potential for health benefits. The results are also a preliminary key reference for future studies in terms of loquat cultivation throughout the world and have high potential as a functional food

    Crystal structure effect in radiation-induced solid-state polymerization of acrylamide

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    Crystal structure of arcylamide at -150 degrees C nas studied to understand the role of the crystal structure on the reaction mechanism of radiation-induced polymerization in the solid-state. Acrylamide crystallizes in the monoclinic unit cell with the unit fell parameters as; a=828.0(2) pm, b=578.0(4) pm, c=974.9(2) pm, beta=119.62(4)degrees, space group =P 2(1)/c, Z=4 molecules/unit cell, d(x) = 1.165 g/cm(3). From the results of the structural data a polymerization mechanism in the solid-state is suggested. The radiation damage in single crystal of acrylamide was also investigated in detail. The result showed the formation of the amorphous polymer, that phase separated from the crystalline monomer. The post polymerization proceed at the interface of poly mer-monomer up to 100% conversion

    Solid-state polymerization of acrylamide N-vinylcarbazole and vinylstearate initiated by gamma radiation.

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    Polymerization of 1,2-epoxy-4-epoxyethylcyclohexane

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    Radiation‐induced polymerization of 1,2‐epoxy‐4‐epoxyethylcyclohexane (EECH) has been carried out at different temperatures in solid and liquid states. Activation energy was calculated from Arrhenius plot and ionic mechanism was proposed. Molecular weights for some polymer samples were determined by cryscopic method and compared with their intrinsic viscosities. Cationic polymerization of EECH initiated by BF3 · O(C2H5)2 and anionic polymerization initiated by NaOH are also studied. Two epoxy rings can be opened for polymerization selectively by radiation, but not by chemical initiators. The expected polyether structure was observed from the IR spectrum. Polymers obtained were shown to be amorphous from X‐ray photographs.Publisher's Versio

    Radiation induced solid-state polymerization of acetylenedicarboxylic acid

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    Radiation induced solid-state polymerization of acetylenedicarboxylic acid was carried out at room temperature in open atmosphere and under vacuum conditions. The gray colored powder polymer obtained was insoluble in most common solvents but only partially soluble in DMSO and THF. The limiting conversion to polymer was about 5%. The polymer was characterized by IR, UV, DP-MS, DSC, TGA, and XRD. The mechanism of polymerization was elucidated from the available data. Polymerization followed a free radical mechanism. However, before the addition of monomer molecules to the growing chain, at least one of the carboxylic groups of the monomer breaks away as CO or CO2. The formation of side group cyclization takes place. At least one of the bonds in the side cyclic group is an etheric bond. The DSC, TGA, and XRD results showed that the polymer was partially crystalline and showed no melting up to 1200degreesC. The mechanism of polymerization and assigned chain structure was studied by the direct pyrolysis mass spectrometric method

    Stereoregular polymerization of methylmethacrylate by atom transfer radical polymerization

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    Methyl methacrylate (MMA) was polymerized by the atom transfer radical polymerization (ATRP) method to obtain living low molecular weight polymers. The initiator was p-toluenesulfonylchloride and the catalyst ligand complex system was CuCl-4,4'dimethyl 2,2'bipyridine. Polymers with controlled molecular weight were obtained. The polymer chains were shown by NMR spectrum to be mostly syndiotactic. The molecular weight distributions were measured by the GPC method. The K and a constants in [eta] = KM alpha equation were measured as 9.13 x 10(-5) and 0.74, respectively. FT- IR and X-Ray results showed steororegularity in polymer chains. The thermal properties were studied by DSC and molecular weight-glass transition temperature relations were determined

    Crystal structure effect in radiation induced solid state polymerization of methacrylamide

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    Radiation induced solid state polymerization of methacrylamide was carried out, opened to atmosphere and under vacuum conditions at room temperature. The white colored powder polymers obtained were insoluble in most common organic solvents such as carbon tetrachloride, dimethysulfoxide, acetone, etc. The polymers were characterized by IR, direct pyrolysis mass spectrometer (DP-MS), XRD, TGA, and DSC methods. The mechanism of the polymerization was elucidated from these results. There were no definite effects of oxygen on the polymerization mechanism. The limiting diffusion of oxygen into the material is due to the close packing of monomer molecules. Polymerization proceeds on the monomerpolymer interface by the opening of the vinyl bond. The polymer obtained was amorphous and did not give a melting peak in DSC thermogram. From the experimental data, it was shown that the polymer gave a side group cyclization upon thermal treatment

    Radiation-Induced Solid-State Polymerization of Allylthiourea and Crystal Structure Effects

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    Allylthiourea crystals grown from water and from ethanol have been found to belong to the space groupP21/c and P21/m or related, respectively. The corresponding unit cell parameters are a = 13.45 Å, b = 17.33 Å,c = 14.38 Å, β = 96.6°, and d = 1.18g/cm3 for water-grown crystals, and a = 14.65 Å, b = 17.18 Å, c = 13.15 Å, β = 95.5°, and 1.17 g/cm3 for ethanol-grown crystals.Publisher's Versio
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