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Hydrophobic Monomer (hydrophobic + monomer)

Distribution by Scientific Domains

Polymers and Materials Science	75%

Selected Abstracts

Using hydroxypropyl-,-cyclodextrin for the preparation of hydrophobic poly(ketoethyl methacrylate) in aqueous medium

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010
Lei Ding
Abstract This work was committed to the polymerization of hydrophobic ketoethyl methacrylate monomer in aqueous medium in the presence of cyclodextrin, instead of polymerizing the monomer in toxic and volatile organic solvents. For this purpose, a new ketoethyl methacrylate monomer, p -methylphenacylmethacrylate (MPMA), was synthesized from the reaction of p -methylphenacylbromide with sodium methacrylate in the presence of triethylbenzylammonium chloride. The monomer was identified with FTIR, 1H and 13C-NMR spectroscopies. Hydroxypropyl-,-cyclodextrin (HPCD) was used to form a water-soluble host/guest inclusion complex (MPMA/HPCD) with the hydrophobic monomer. The complex was identified with FTIR and NMR techniques and polymerized in aqueous medium using potassium persulfate as initiator. During polymerization the resulting hydrophobic methacrylate polymer precipitated out with a majority of HPCD left in solution and a minority of HPCD bonded on the resulting polymer. The thus-prepared polymer exhibited little difference from the counterparts obtained in organic solvent in number average molecular weight (Mn), polydispersity (Mw/Mn) and yield. The investigation provides a novel strategy for preparing hydrophobic ketoethyl methacrylate polymer in aqueous medium by using a monomer/HPCD inclusion complex. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Poly(ethylene glycol)-based amphiphilic model conetworks: Synthesis by RAFT polymerization and characterization

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2008
Mariliz Achilleos
Abstract Poly(ethylene glycol) (PEG)-containing quasi-model amphiphilic polymer conetworks (APCNs) were prepared by reversible addition fragmentation chain transfer (RAFT) polymerization using ,,,-bis(2-cyanoprop-2-yl dithiobenzoate)-PEG as a bifunctional RAFT macrochain transfer agent (macro-CTA) and stepwise additions of a hydrophobic monomer and a crosslinker (crosslinker: macro-CTA = 10:1, reaction time 24 h). Three different types of monomers, methyl methacrylate (MMA), n -butyl acrylate and styrene, were employed as the hydrophobic monomers, whereas ethylene glycol dimethacrylate, ethylene glycol diacrylate and 1,4-divinylbenzene served as the respective crosslinkers. PEG homopolymer hydrophilic quasi-model networks were also prepared by RAFT-polymerizing the three crosslinkers directly onto the two active ends of the PEG-based macro-CTA. From the three ABA triblock copolymers prepared, the MMA-containing one was obtained at the highest polymerization yields. The crosslinking yields of the three ABA triblock copolymers with the corresponding crosslinkers were higher than those of the PEG-based macro-CTA with the same crosslinkers. The degrees of swelling (DSs) of all conetworks were measured in water and in tetrahydrofuran (THF). The DSs of the APCNs in THF were higher than those in water, whereas the reverse was true for the DSs of the hydrophilic homopolymer networks. Finally, the aqueous DSs of the APCNs were lower than those of the corresponding hydrophilic homopolymer networks. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7556,7565, 2008 [source]

Confinement effects on the morphology of photopatterned porous polymer monoliths for capillary and microchip electrophoresis of proteins

ELECTROPHORESIS, Issue 14 2008
Mei He
Abstract We find that the morphology of porous polymer monoliths photopatterned within capillaries and microchannels is substantially influenced by the dimensions of confinement. Porous polymer monoliths were prepared by UV-initiated free-radical polymerization using either the hydrophilic or hydrophobic monomers 2-hydroxyethyl methacrylate or butyl methacrylate, cross-linker ethylene dimethacrylate and different porogenic solvents to produce bulk pore diameters between 3.2 and 0.4,µm. The extent of deformation from the bulk porous structure under confinement strongly depends on the ratio of characteristic length of the confined space to the monolith pore size. The effects are similar in cylindrical capillaries and D-shaped microfluidic channels. Bulk-like porosity is observed for a confinement dimension to pore size ratio >10, and significant deviation is observed for a ratio <5. At the extreme limit of deformation a smooth polymer layer ,300 nm thick is formed on the surface of the capillary or microchannel. Surface tension or wetting also plays a role, with greater wetting enhancing deformation of the bulk structure. The films created by extreme deformation provide a rapid and effective strategy to create robust wall coatings, with the ability to photograft various surface chemistries onto the coating. This approach is demonstrated through cationic films used for electroosmotic flow control and neutral hydrophilic coatings for electrophoresis of proteins. [source]