The Poly (vinyl alcohol)/Kefirane nanofiber membrane was successfully fabricated for the firsttime using electrospinning of the polyvinyl alcohol (PVA) and Kefirane blend solution. Scanningelectron microscope (SEM), attenuated total reflectance Fourier transform infrared (ATRFT-IR), and differential scanning calorimetry (DSC) were used to characterize the electrospunPoly (vinyl alcohol)/Kefiran...

Rotational isomeric state theory has been used to calculate mean-square unperturbed dimensions (r2>0 and dipole moments (/~> of ethylene-vinyl chloride copolymers as a function of chemical composition, chemical sequence distribution, and stereochemical composition of the vinyl chloride sequences. As was previously found for several other copolymeric chains, (/z2> is much more sensitive to chemi...

Vinyl cations, the dicoordinated unsaturated analogues of trivalent carbenium ions, were first detected by Grob and coworkers in the early 1960s in solvolysis reactions of a-aryl vinyl halides. In the 1970s numerous investigations established vinyl cations as reaction intermediates in solvolysis reactions of activated alkenyl halides and in reactions of electrophiles with alkynes. The direct NM...

The carcinogenicity of vinyl chloride for experimental animals when administered transplacentally is reviewed in comparison with known transplacental carcinogens, including those that, like vinyl chloride, are dependent on enzyme-mediated metabolic conversion to a reactive intermediate in maternal or fetal tissues. Vinyl chloride is converted by mixed-function oxidases to the reactive metabolit...

objective(s): three-dimensional structures such as nanofibrous scaffolds are being used in biomedical engineering as well as provide a site for cells to attach and proliferate leading to tissue formation. in the present study, poly(vinyl pyrrolidone) (pvp)/ poly(vinyl alcohol)(pva) hybrid nanofibrous scaffold was synthesized by electrospinning. materials and methods: the effect of adding nano h...

0

Unsaturated polyester and epoxy vinyl ester resins have broad utility in composite applications. Today’s commercially available premium thermal performance vinyl ester resins are derived from novolac epoxies and methacrylic acid. These products combine low viscosity with shelf stable, yet fast curing properties, and enable fabricators to manufacture composite parts with rapid throughput for dem...

A series of N-substituted imidazole derivatives was synthesized. Imidazole nucleus was reacted with ethylchloroacetate to form imidazole ester. Reaction of the imidazole ester (I) with different amines yields the desired products (1a- 1e). The compounds were characterized by FT-IR, (1)H-NMR and mass spectra. The synthesized compounds were evaluated for the antimicrobial activity against Staphyl...

The imidazole ring in the title compound, C(27)H(22)N(8), adopts a slight envelope conformation with the C atom carrying the phenyl ring being the flap atom. The phenyl ring is almost perpendicular to the mean plane of the imidazole ring [dihedral angle = 88.90 (7)°]. The (1H-benzotriazol-1-yl)methyl groups bound to the imidazole ring are positioned on the same side of the imidazole ring. The d...

Imidazole compounds are important constituents of atmospheric brown carbon. The imidazole components aqueous secondary organic aerosol (aqSOA) that generated from the evaporation droplets containing pyruvaldehyde and inorganic ammonium on-line characterized by an laser time-of-flight mass spectrometer (ALTOFMS) off-line detected optical spectrometry in this study. results demonstrated desorptio...