Styrene (Sty), methyl methacrylate (MMA), methacrylamide (MAm) and acrylomorpholine (AcM) were grafted onto powder cellulose by atom-transfer radical polymerization. Cellulose chloroacetate (Cell-ClAc), as a macro-initiator, was first prepared by the reaction of chloroacetyl chloride with primary alcoholic OH groups on powder cellulose. CuBr and 1,2-dipiperidinoethane were used as a transition-metal compound and as a ligand, respectively. These reactions were monitored by FT-IR and weight increase in Cell-ClAc. In case of styrene, although some weight increase occurred, no evidence of grafting could be observed in the FT-IR spectrum, while there were strong evidence of grafting with MMA, MAm and AcM. Cell-graft-MAm, Cell-graft-AcM and Cell-graft-MMA showed new carbonyl bands at 1665, 1640 and 1735 cm −1 , respectively. Dye-uptake and dye-absorption properties of cellulose, for alizarin yellow (basic dye) and bromocresol green (acidic dye), and its moisture-and water-uptake capacities improved with the grafting, but some decrease was observed in thermal stability.
The blends of two different ultra high molecular weight polyethylenes (UHMWPE) and high density polyethylene (HDPE) were prepared in melt at different compositions and mixing rates in Brabender Torque Rheometer. The temperature build‐up due to the internal friction during melt blending was recorded and evaluated with respect to the change in the torque. The temperature at maximum torque was considered the fusion point temperature of the UHMWPE in the blend. This fusion point temperature was found to depend on the composition, mixing rate, and molecular weight. The effect of mixing rate on the mechanical properties (measured as yield and tensile strengths and elongation at break), thermal oxidative degradation and melting behavior were studied. The morphology of the blends were investigated by optical microscopy.
Copolymerization and homopolymerization of benzyl methacrylate (BMA) and ethyl methacrylate (EMA) by the atom transfer radical polymerization method (ATRP) were performed at 90°C. ATRP of BMA was also carried out at 80, 100, and 110°C. The number-average molecular weight (M n ) and polydispersities decreased with temperature. When BMA units increased in the copolymer system, the M n values and polydispersities decreased (1.63 Ͻ M w /M n Ͻ 1.13). The homopolymers and poly(BMAco-EMA) were characterized by Fourier transform infrared (FTIR), 1 H and 13 C NMR, and gel permeation chromatography (GPC) techniques. The compositions of the copolymers were calculated from 1 H NMR spectra. For the atom transfer radical copolymerization system, their monomer reactivity ratios were obtained by using the Kelen-Tü dös equation, as r 1 ϭ 0.812, r 2 ϭ 1.162 (r 1 is the monomer reactivity ratio of BMA). The initial decomposition temperatures of the resultant copolymers decrease with an increasing mol fraction of BMA, which indicates that the heat resistance of the copolymer has been improved by decreasing the BMA units. Blends of poly(BMA) and poly(EMA) obtained via the ATRP method have been prepared by casting films from a dichlorormethane solution. The blends have been characterized by differential scanning calorimetry and thermogravimetry. The measurements were comparable with those of copolymers synthesized.
Benzofuran derivatives are of great interest in medicinal chemistry and have drawn considerable attention due to their diverse pharmacological profiles including anticancer activity. Similarly, chalcones, which are common substructures of numerous natural products belonging to the flavonoid class, feature strong anticancer properties. A novel series of chalcones, 3-aryl-1-(5-bromo-1-benzofuran-2-yl)-2-propanones propenones (3a–f), were designed, synthesized, and characterized.In vitroantitumor activities of the newly synthesized (3a–f) and previously synthesized (3g–j) chalcone compounds were determined by using human breast (MCF-7) and prostate (PC-3) cancer cell lines. Antitumor properties of all compounds were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell viability assay for the tested chalcone compounds was performed and thelogIC50values of the compounds were calculated after 24-hour treatment. Our results indicate that the tested chalcone compounds show antitumor activity against MCF-7 and PC-3 cell lines (p<0.05).
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