Permeability of block copolymers is an important feature for a broad range of applications including packaging, bio-materials (e.g. for controlled release or encapsulating membranes), barrier materials, high performance impermeable breathable clothing and membrane separation processes. This paper reviews the literature on permeability of block copolymers to pure or mixed vapors and liquids for ...

Water-soluble copolymers such as polyvinylpyrrolidone and polyvinyl alcohol have been widely used detergents, paints, chemical intermediates in many industrial processes, leading to environmental concerns associated with high-volume organic compound wastewater. Therefore, this study, a combined upflow anaerobic sludge blanket (UASB) reactor downflow hanging sponge (DHS) biosystem has applied fo...

4-chloromethyl styrene homopolymer and its copolymers with styrene were prepared from their corresponding 4-chloromethyl styrene and styrene monomers at 1:0, 1:1, 1:3 and 1:5 mole ratios. these homo- and copolymerswere synthesized by radical polymerization in presence of aibn as initiator and dry toluene as solvent. then, chloromethyl groups were converted into azidomethyl groups on the homo- a...

Aqueous solutions of a Pluronic copolymer P104 have been investigated by rheological techniques in order to characterize its gelation and its gel properties. P104 solutions have a low viscosity at low temperatures but form an elastic gel at physiological temperatures. Elastic moduli are of the order 10 kPa with a significant yield stress. Possible use of P104 to prevent flow in pipes or blood v...

Bovine rumen fluid was fermented anaerobically with 25 mM R-propylene glycol, S-propylene glycol, or glycerol added. After 24 h, all of the propylene glycol enantiomers and approximately 80% of the glycerol were metabolized. Acetate, propionate, butyrate, valerate, and caproate concentrations, in decreasing order, all increased with incubation time. Addition of any of the three substrates somew...

The selective oxidation of propylene with O2 to propylene oxide and acrolein is of great interest and importance. We report the crystal-plane-controlled selectivity of uniform capping-ligand-free Cu2 O octahedra, cubes, and rhombic dodecahedra in catalyzing propylene oxidation with O2 : Cu2 O octahedra exposing {111} crystal planes are most selective for acrolein; Cu2 O cubes exposing {100} cry...

Propylene oxide (1,2-epoxypropane) is a nasal toxicant and weak site-of-contact carcinogen in the rodent. The current study was aimed at providing quantitative information on upper respiratory tract (URT) dosimetry of this vapor. Since depletion of nasal non-protein sulfhydryls (NPSH) may be important in the toxicity of this vapor and may serve as a biomarker for delivery of propylene oxide to ...

Separation of propylene-propane mixture using immobilized liquid membrane was investigated. The effect of transmembrane pressure and carrier concentration on membrane separation performance was studied. It was observed that for 30:70 (vol. %) propylene-propane mixture, at pressure of 120kPa and carrier concentration of 20wt. %, a separation factor of 474 was obtained. Keywords—Facilitated Trans...

water soluble amphoteric graft copolymers of polysaccharide were synthesized via grafting of cationic monomer onto the sodium carboxymethylcellulose ()cmc)( and then used as a shale stabilizer in the water-based drilling fluids. accordingly, five types of cmc-graft copolymers with different ratios of acrylamide am)( and diallyldimethylammonium chloride dadmac)( were synthesized. grafting of mon...