• Polymer(Korea)
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• v.26 no.6
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• pp.710-717
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• 2002

Molecularly imprinted polymers were prepared in particle forms by crosslinking methacrylic acid (MAA)) using all trans-retinoic acid as a template. The HPLC column packed with the prepared molecular imprinted polymers showed high capability in separation of retinoid derivatives. The column capacity factor and selectivity increased with increasing MAA to template ratio when the incorporated template amount was fixed, as it statistically generated more binding sites between host molecules and template. Molecularly imprinted polymer particles prepared via an emulsion polymerization method were round-shaped and their sizes were more uniformly distributed, but their separation capability was inferior to those obtained by solution polymerization method. It was presumably because the loss of interaction strength between MAA and the template due to hydrogen bonding either between MAA and water or between template and water during the synthesis of molecularly imprinted polymers.

• Bulletin of the Korean Chemical Society
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• v.17 no.4
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• pp.376-379
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• 1996

The bulk photopolymerization of methacrylic acid (MA) with phenylsilane was performed to produce poly(MA)s containing phenylsilyl moiety presumably as an end group. It was found that while the polymerization yields and intrinsic viscosities decreased, the TGA residue yields and the relative intensities of SiH IR stretching bands increased with increasing molar ratio of phenylsilane over MA. The phenylsilane seemed to significantly influence on the photopolymerization as both chain initiation and chain transfer agents.

• Journal of Pharmaceutical Investigation
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• v.41 no.2
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• pp.111-115
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• 2011

pH-sensitive cross-linked polymeric micelles were synthesized by using block ionomer complexes of poly(ethylene oxide)-b-poly(methacrylic acid) (PEO-b-PMA) with calcium ions as micellar templates. An anticancer drug, doxorubicin (DOX) was conjugated on the cross-linked ionic cores of micelles via acid-labile hydrozone bonds. The resulting DOX-conjugated, pH-sensitive micelles are stable at physiological conditions, whereas the release of DOX was significantly increased at the acidic pH. Such micelles were internalized to lysosomes, and acidic pH in lysosomes triggers the release of DOX upon internalization in MCF-7 breast cancer cells. The released DOX entered the cell nucleus and eventually killed cancer cells. Therefore, these data demonstrate that the pH-sensitive micelles could be a promising nanocarrier for delivery of anticancer drug, DOX.

• Macromolecular Research
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• v.13 no.4
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• pp.327-333
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• 2005

pH-sensitive hydrogels were studied as a drug carrier for the protection of insulin from the acidic environment of the stomach before releasing it in the small intestine. In this study, hydrogels based on poly(ethylene oxide) (PEO) networks grafted with methacrylic acid (MAA) or acrylic acid (AAc) were prepared via a two-step process. PEO hydrogels were prepared by ${\gamma}-ray $ irradiation (radiation dose: 50 kGy, dose rate: 7.66 kGy/h), grafted by either MAA or AAc monomers onto the PEO hydrogels and finally underwent irradiation (radiation dose: 520 kGy, dose rate: 2.15 kGy/h). These grafted hydrogels showed a pH-sensitive swelling behavior. The grafted hydrogels were used as a carrier for the drug delivery systems for the controlled release of insulin. Drug-loaded hydrogels were placed in simulated gastric fluid (SGF, pH 1.2) for 2 hr and then in simulated intestinal fluid (SIF, pH 6.8). The in vitro drug release behaviors of these hydrogels were examined by quantification analysis with a UV-Vis spectrophotometer.

• Korean Membrane Journal
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• v.9 no.1
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• pp.57-63
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• 2007

Amphiphilic graft copolymer from poly(vinylidene fluoride) (PVDF) was synthesized using atom transfer radical polymerization (ATRP) for composite nanofiltration membranes. Direct initiation of the secondary fluorinated site of PVDF facilitates grafting of tert-butyl methacrylate (tBMA). Amphiphilic PVDF-g-PMAA graft copolymer with a 51:49 wt ratio was obtained by hydrolyzing poly(tert-butyl methacrylate) (PtBMA) to poly(methacrylic acid) (PMAA). Wide angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC) confirmed the decrease of crystallinity of PVDF upon graft copolymerization. Composite nanofiltration membranes were prepared from PVDF-g-PMAA as a top layer coated onto PVDF ultrafiltration (UF) support membrane. The morphology and hydrophilicity of membranes were characterized using scanning electron microscopy (SEM) and contact angle measurement. The rejections of composite membranes were 80.2% for $Na_2SO_4$ and 28.4% for NaCl, and the solution flux were 9.5 and $14.5\;L/m^2\;h$ at 1.0 MPa pressure.

• Elastomers and Composites
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• v.48 no.4
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• pp.294-299
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• 2013

Solution polymerization was conducted with water-soluble methacrylic acid (MAA) as a monomer and potassium persulfate (KPS) as an initiator at a selected temperature between $70^{\circ}C$ and $90^{\circ}C$. When the ratio between MAA and water was reduced or initiator concentration increased, molecular weights decreased. Molecular weights of poly(methacrylic acid) (PMAA) showed nearly no dependence on reaction temperature. The Weissenberg effect was observed in most polymerization reactions, while its effect weakened at $90^{\circ}C$. The polydispersity index was less than 1.5 in most of the reactions. An increase in the stirring speed produced PMAAs with increasing molecular weights. When the stirring speed reached 800 rpm, we retrieved a monodisperse PMAA with both the number and weight average molecular weights of 791,000 g/mol. The glass transition temperature was found to be $162^{\circ}C$.

• Proceedings of the Korean Fiber Society Conference
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• 1990.06b
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• pp.12-12
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• 1990

• Bulletin of the Korean Chemical Society
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• v.17 no.6
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• pp.532-535
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• 1996

The bulk photopolymerization of methacrylic acid (MA) with secondary silanes such as PhMeSiH2 and Ph2SiH2 gave poly(MA)s possessing the secondary silyl moiety presumably as an end group. It was found that while the polymerization yields and intrinsic viscosities decreased, the TGA residue yields and the relative intensities of SiH IR stretching bands increased with increasing mole ratio of the secondary silane over MA. The sterically less bulky silane PhMeSiH2 produced poly(MA)s with somewhat higher molecular weights and with similar TGA residue yields compared with the sterically bulkier silane Ph2SiH2. The secondary silanes seem to significantly influence on the photopolymerization of MA as both chain initiation and chain transfer agents.

• Archives of Pharmacal Research
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• v.26 no.8
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• pp.649-652
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• 2003

Polymeric nanoparticles composed of polystyrene (PS) as core and poly(methacrylic acid) (PMA) as corona were prepared by the dispersion copolymerization. The potential of the nanoparticles as carriers for recombinant human epidermal growth factor (EGF) was investigated. The nanoparticles showed monodispersity and good water-dispersibility. The loading content of EGF to the nanoparticles was very high due to electrostatic interaction between EGF and nanoparticles. EGF was released as a pseudo-zero order pattern after initial burst effect. The nanoparticles were sufficient for A431 cells proliferation.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2004.11a
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• pp.273-273
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• 2004