Opis: A series of monolithic crosslinked polymers with 2,4,6-trichlorophenyl acrylate as a reactive component was prepared by free radical polymerization of the internal phases of high internal phase emulsions (HIPEs). The volume ratio of water to oil phase (void volume; 60-90%), crosslinker type (divinylbenzene or ethylenglycol dimethacrylate) and quantity (30-50 mol %) and type of porogenic solvent (chlorobenzene, toluene, chloroform, dichloroethane) were altered to study these effects on the structure and reactivity of the monolithic polymers. The polymer supports were characterizedby scanning electron microscopy (SEM), FTIR spectroscopy, elemental analysis and mercury intrusion porosimetry. SEM images revealed an open cellular structure with voids between 1 and 12 ▫$/mu$▫m and window sizes between 0.3 and 3 ▫$/mu$▫m. The porogen had an influence on the surface area, being larger with added porogen and the influence being highest with toluene. Addingtoluene also influenced the void size, increasing the average diameter from 2 ▫$/mu$▫m (no porogen) to 12 ▫$/mu$▫m (added toluene). Monolithic supports were functionalized by reaction of the ester moieties with tris(2-aminoethyl)amine derivative and by hydrolysis of the ester groups to carboxylic acids.Najdeno v: ključnih besedahPovzetek najdenega: ... organic chemistry, aryl acrylates, monolythic polymers, monoliths, functionalization...Ključne besede: organic chemistry, aryl acrylates, monolythic polymers, monoliths, functionalization of polymers, emulsion templating, emulsion polymerisation, macroporous polymers, morphology, polyHIPE, polymer supports, supports, 2, 4, 6-trichlorophenyl acrylateObjavljeno: 31.05.2012; Ogledov: 174; Prenosov: 0 Polno besedilo (0,00 KB)
Opis: Preparation of highly porous (up to 80% pore volume) open-cellular monolithic cross-linked polymers from 2-hydroxyethyl methacrylate is reported. Oil-in-water and water-in-oil high internal phase emulsions are applied as porosity templates, resulting in an interconnected porous structure with void diameters between 550 nm and 18 m. Significantly larger voids were obtained inthe case of oil-in-water emulsions (between 5 and 18 m) as opposed to water in oil emulsions (approx 600 nm). Controlled coarsening exploiting limited kinetical stability of emulsions was used to obtain monoliths with larger voids, diameters being enlarged 3-fold.Najdeno v: ključnih besedahPovzetek najdenega: ... organic chemistry, polymerization, monolithic polymers, HIPE, emulsions, porous...Ključne besede: organic chemistry, polymerization, monolithic polymers, HIPE, emulsions, porous materials, methacrylatesObjavljeno: 31.05.2012; Ogledov: 156; Prenosov: 0 Polno besedilo (0,00 KB)
Opis: Porous monolithic polymers are objects of many studies recently due to their wide applicability. Especially in separation methods use of monoliths is growing. Usually, porous monoliths are prepared by bulk polymerisation with the use of porogenic solvents. An alternative way of preparation is to polymerise the continuous phase of an emulsion. When the volume fraction of the internal phase exceeds 74%, the emulsion is called a HIPE (high internal phase emulsion), and a polymer derived from it, a PolyHIPE. PolyHIPEs of styrene, vinylbenzyl chloride and acrylate chemistry have been prepared from awater in oil emulsion system, where monomers are dissolved in the organic phase. We describe the reversed procedure, an oil in water high internal phaseemulsion, where monomers are water soluble. Porous polymers based on acrylic acid and crosslinked with methylenebisacrylamide were prepared by using a high internal phase emulsion with toluene as the oil phase. The influence of initiator and surfactant on the morphology was studied.Najdeno v: ključnih besedahPovzetek najdenega: ...system, where monomers are dissolved in the organic phase. We describe the reversed procedure, an... ...PolyHIPEs of styrene, vinylbenzyl chloride and acrylate chemistry have been prepared from awater in oil...Ključne besede: organic chemistry, porous monolith polymers, polymer supports, preparation, emulsion polymerization, HIPEObjavljeno: 01.06.2012; Ogledov: 144; Prenosov: 2 Polno besedilo (0,00 KB)
Opis: Water-in-oil high-internal-phase emulsions (HIPEs), containing 4-nitrophenyl acrylate and 2,4,6-trichlorophenyl acrylate as reactive monomers, were prepared and polymerized, and highly porous monolithic materials resulted. The novel materials were studied by combustion analysis, Fourier transform infrared spectroscopy scanning electron microscopy, mercury porosimetry, and N2 adsorption/desorption analysis. With both esters, cellular macroporous monolithic polymers were obtained: the use of 4-nitrophenyl acrylate resulted in a cellular material with void diameters between 3 and 7 m and approximately3-m interconnects, whereas the use of 2,4,6-trichlorophenyl acrylate yielded a foam with void diameters between 2 and 5 m, most interconnects being around 1 m. The resulting monoliths proved to be very reactive toward nucleophiles, and possibilities of functionalizing the novel polymer supports were demonstrated via reactions with amines bearing additional functional groups and via the synthesis of an acid chloride derivative. Tris(hydroxymethyl)aminomethane and tris(2-aminoethyl)amine derivatives were obtained. The hydrolysis of 4-nitrophenylacrylate removed thenitrophenyl group, yielding a monolithic acrylic acid polymer. Furthermore,functionalization to immobilized acid chloride was performed very efficiently, with more than 95% of the acid groups reacting. The measurement of the nitrogen content in 4-nitrophenyl acrylate poly(HIPE)s after various times of hydrolysis showed the influence of the total pore volume of the monolithic polymers on the velocity of the reaction, which was faster with themore porous polymer.Najdeno v: ključnih besedahPovzetek najdenega: ... organic chemistry, macroporous polymers, monolithic polymer supports, emulsion...Ključne besede: organic chemistry, macroporous polymers, monolithic polymer supports, emulsion polymerisation, foams, functionalization of polymers, high-internal-phase emulsionsObjavljeno: 01.06.2012; Ogledov: 166; Prenosov: 0 Polno besedilo (0,00 KB)
Opis: Poly(glycidyl methacrylate-co-ethyleneglycol dimethacrylate) monolithic supports were prepared by radical polymerisation of the continuous phase of water in oil high internal phase emulsions. Morphology of monolithic materialswas studied by scanning electron microscopy and mercury intrusion porosimetry. The ratio of phase volume and the degree of crosslinking influenced the void size and pore size distribution of resulting polymers. Void sizes between 1 and 10 m were observed and average pore sizes around 100nm. Polymers with 60, 75, 80 and 90% pore volume were prepared and even samples with highest pore volume showed good mechanical stability. They were modified to bear weak-anion exchange groups and tested on the separation of standard protein mixture containing myoglobin, conalbumine and trypsin inhibitor. Good separation was obtained in a very short time similar to the separation obtained by commercial methacrylate monoliths. However, higher dispersion was observed. Bovine serum albumin dynamic binding capacity for monolith with 90% porosity was close to 9 mg/ml.Najdeno v: ključnih besedahPovzetek najdenega: ... organic chemistry, methacrylate monoliths, preparation, emulsion polymerization, high...Ključne besede: organic chemistry, methacrylate monoliths, preparation, emulsion polymerization, high porosity, high mechanical stability, polymer chromatographic supports, monolithic methacrylate supports, protein separationObjavljeno: 01.06.2012; Ogledov: 139; Prenosov: 0 Polno besedilo (0,00 KB)
Najdeno v: ključnih besedahKljučne besede: colour chemistry, organic dyes, pigmentsObjavljeno: 01.06.2012; Ogledov: 91; Prenosov: 0 Polno besedilo (0,00 KB)
