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Hollow microspheres were synthesized using an oil in water suspension system. The oil droplets were comprised of ethylene glycol dimethacrylate (EGDMA) and n-butyl acetate. Upon radical polymerization and gel formation, the polymer phase-separated from the solution and precipitated on the interface between water and organic solvent. The solvent n-butyl acetate was found to be crucial in the process...
Microspheres have been modified post-polymerization via Michael Addition to suit the requirement of these beads as a drug delivery carrier for platinum drugs. Ethyleneglycol dimethacrylate (EGDMA) was polymerized in a suspension system leading to microspheres with an excess of vinyl functionalities. Solid state NMR was employed to determine the amount of repeating groups with unreacted vinyl groups...
The coupling of the reversible addition fragmentation chain transfer (RAFT) polymerization technique with the copper-catalyzed Huisgen 1,3-dipolar cycloaddition (“click chemistry”) as a simple and effective way to generate polystyrene (PS) macrocycles is presented. The novel strategy entails the synthesis of linear PS backbones followed by endgroup modification to facilitate click chemistry for the...
The synthesis of polystyrene-block-poly(N,N-dimethylacrylamide) (PS-b-PDMA) via RAFT polymerization was investigated in detail. Two different RAFT agents – benzyl dithiobenzoate and 3-(benzylsulfanylthiocarbonylsufanyl) propionic acid, were employed to prepare polystyrene macroRAFT agents with molecular weights varying between 3000gmol −1 and 62,000gmol −1 and polydispersities between...
Living free radical polymerization technology (macromolecular design via the interchange of xanthates (MADIX)) was applied to give accesses to chain length and conversion dependent termination rate coefficients of vinyl acetate (VAc) at 80°C using the MADIX agent 2-ethoxythiocarbonylsulfanyl-propionic acid methyl ester (EPAME). The kinetic data were verified and probed by simulations using the PREDICI...
Poly(vinyl acetate) combs have been prepared via macromolecular design via interchange of xanthate (MADIX)/reversible addition–fragmentation chain-transfer (RAFT) polymerization using xanthate functionalized polymer cores. The comb backbones were prepared using well-defined poly(vinyl alcohol) PVA polymers with a degree of polymerization of 20, 100 and 170, respectively. Functionalization with xanthates...
The effect of an added base on the aqueous reversible addition–fragmentation chain transfer polymerization of a methacrylic glycomonomer with (4-cyanopentanoic acid)-4-dithiobenzoate was investigated. When sodium carbonate or sodium bicarbonate were used to dissolve the RAFT agent in aqueous solution at room temperature, an inhibition period of 60–90min was observed at the beginning of the polymerization...
Coupled size exclusion chromatography (SEC)–electrospray ionization mass spectrometry (ESI-MS) was applied to carefully map the product spectrum of a series of acrylate free radical polymerizations mediated via the reversible addition fragmentation chain transfer (RAFT) process. The product stream of a significantly rate retarded RAFT system (i.e. n-butyl acrylate (BA)/cumyl dithiobenzoate (CDB))...
The reversible addition fragmentation chain transfer-chain length dependent-termination (RAFT-CLD-T) methodology was employed to map chain length dependent termination rate coefficient, kti,i, in dodecyl acrylate (DA) free radical polymerization at 60 and 80°C. The chain length of the propagating DA radicals was controlled by the RAFT agents methoxycarbonylethyl phenyldithioacetate (MCEPDA) and dimethoxycarbonylethyl...
The vinyl ester-type glycomonomer 6-O-vinyladipoyl-d-glucopyranose was polymerized in water and alcohol solutions. In all cases, long polymerization times were necessary to achieve reasonable conversions. Depending on the nature of the solvent, polydisperse glycopolymers were obtained possessing a molecular weight ranging between 10,000 and 122,000Da (PS equivalent). Higher alcohols appeared to act...
Side-chain liquid crystalline block polymers containing a poly[6-[4-(4′-methoxyphenyl)phenoxy]hexyl methacrylate] (PMMA-LC) segment and a styrene-co-maleic anhydride segment (alternating structure) were prepared via reversible addition fragmentation chain transfer (RAFT) polymerization. PMMA-LC was initially prepared via RAFT polymerization mediated by 2-(2-cyanopropyl)dithiobenzoate (CPDB). The resulting...
The present feature article provides an overview on the use of state-of-the-art mass spectrometry techniques such as matrix assisted laser desorption and ionization time of flight (MALDI-TOF) mass spectrometry as well as electrospray ionization mass spectrometry (ESI-MS) for probing the mechanism of free radical polymerization processes. The article features representative examples of the application...
Dihydroxy terminated poly(dimethyl siloxane) (PDMS) was modified to form a di(trithiocarbonate) functional molecule capable of forming tri-block copolymers via the reversible-addition-fragmentation chain transfer (RAFT) process. Two statistical copolymer blocks were grown from the central PDMS block, comprising units of N,N-dimethyl acrylamide (DMA) and 2-(N-butyl perfluorooctanefluorosulfonamido)...
Reversible addition fragmentation chain transfer (RAFT) mediated and conventional copolymerizations at low monomer conversions have been carried out for the systems methyl methacrylate (MMA)-styrene, methyl acrylate (MA)-styrene and methyl methacrylate-butyl acrylate (BA). The polymer samples have been analyzed via 1 H-NMR spectroscopy to obtain the copolymer composition and the terminal model...
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