• Bulletin of the Korean Chemical Society
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• v.26 no.7
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• pp.1037-1043
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• 2005

Kinetic study on the cleavage of N-methylphthalamic acid (NMPA) in mixed acidic aqueous-acetonitrile solvent reveals the formation of both phthalic anhydride (PAn) (through O-cyclization) and N-methylphthalimide (NMPT) (through N-cyclization). The formation of NMPT varies from $\sim$20% to $\sim$3% with the increase in the content of acetonitrile from 2 to 70% v/v. Pseudo first-order rate constants for the formation of PAn are more than 4-fold larger than those for the formation of NMPT at 2% v/v $CH_3CN$ in mixed aqueous solvents. Pseudo first-order rate constants for alkaline hydrolysis of NMPT reveal a nonlinear decrease with increase in the content of $CH_3CN$ in mixed aqueous solvents.

• Journal of the Korean Chemical Society
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• v.48 no.6
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• pp.609-615
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• 2004

Alkoxyallylthiopyridazine derivatives which exhibit superior effect for the treatment of hepatic diseases were synthesized from maleic anhydrides. The reaction of maleic anhydrides with hydrazine monohydrate in aq HCl at reflux afforded dihydroxypyridazines, which were transformed to dichloropyridazines with phosphorus oxychloride. The substitution of the first chlorine atom in dichloropyridazines proceeded selectively with alcoholic sodium alkoxides in THF to afford alkoxychloropyridazines, which were converted to alkoxyallylthiopyridazines with lithium 2-propene-1-thiolate in high yields.

• Macromolecular Research
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• v.13 no.4
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• pp.297-305
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• 2005

The compatibilizing effect of maleic anhydride (MA) in the immiscible blends of EVA22 (vinyl acetate content 22%)/ethylene-${\alpha}$-olefin copolymers with 1-butene (EtBC) and 1-octene (EtOC)) comonomers was studied. By adding 1, 2, and 3 phr of MA in the presence of dicumylperoxide, the morphology, tensile strength at break, and 100 and 300 % modulus of EVA22/EtBC and EVA22/EtOC blends were significantly enhanced. The melting point and crystallization point depression were observed upon the addition of MA. The changes in the ${\beta}$ transition and glass transition temperature of ethylene-${\alpha}$-olefin copolymers and ethylene-vinyl acetate copolymers, respectively, indicate that MA plays a role of compatibilizer for these immiscible blends. The TGA thermograms, measured from the blends with MA, show that thermal stability is slightly enhanced with MA, indicating that MA acts as a reinforcing agent either by grafting or crosslinking with other copolymers.

• Journal of the Korean Society of Industry Convergence
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• v.13 no.2
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• pp.93-98
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• 2010

Polypropylene / montmorillonite / wood flour nanocomposites are melt-mixed by using a twin screw extruder. The montmorillonite is intercalated by the wood flour and the basal spacing of montmorillonite is increased with increasing the content of wood flour. The exfoliation constantly occurs by adding more than 10 wt.% of maleic anhydride-grafted polypropylene as the compatibilizer, which is used for improving the interfacial adhesion between matrix and filler. Also, the maleic anhydride-grafted polypropylene enhances the mechanical properties of the nanocomposites.

• Bulletin of the Korean Chemical Society
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• v.12 no.1
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• pp.85-87
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• 1991

Poly[(tri-O-acetyl-D-glucal)-alt-(maleic anhydride)] was synthesized by free radical copolymerizations of the relevant comonomers. The alternating sequence of the copolymer was confirmed by $^1$H-NMR, elemental analysis, and titration of anhydride groups incorporated into the copolymer. Hydrolysis of the copolymer under different conditions resulted in poly[(2-acetoxymethyl-3,4-diacetoxytetrahydropyran-5,6-diyl) (1,2-dicarboxyethylene)] and poly[(2-hydroxymethyl-3,4-dihydroxytetrahydropyran-5,6-diyl) (1,2-dicarboxyethylene)]. The cytotoxicities of these polymers measured against normal and tumor cells (3LL, B16) in vitro were found to be higher than that of DIVEMA, a prototype polymer having a high antitumor activity.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.894-900
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• 1998

An interphase between carbon fiber and epoxy matrix was introduced to increase impact strength of carbon fiber reinforced composites (CFRC) without sacrificing the interlaminar shear strength. Flexible polymers, I. e., MVEMA (poly(methyl vinyl ether-co-maleic anhydride)) and EMA(poly(ethylene-co-maleic anhydride)), which have reactive functional groups were considered as interphase materials. Weight hain of MVEMA and EMA onto the surface of carbon fibers was evaluated by changing the parameters of electrodeposition process. Electrodeposition mechanism of polymers which have anhydride functional group was identified by IR spectroscopy, that is, the generation of $RCOO^-$ functional group by the attack of hydroxide anion in the basic solution was observed. The weight gain was increased by increasing concentration of polymers, current density, and electrodeposition time. However the excess generation of oxygen gas decreased the weight gain by removing the deposited polymers. Washing in the running water easily removed the deposited polymers which are on the fiber surface without bonding, as a results, only 0.5 wt% of deposited polymers are remained.

• Polymer(Korea)
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• v.29 no.2
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• pp.127-134
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• 2005

The relationships among mechanical properties, rheological properties, and morphology by reactive extrusion based on commingled pckaging film wastes contains polypropylene (PP) pckaging film system [PP/polyethylene (PE)/aluminum (Al)/poly(ethylene terephthalate) (PET)] and Nylon packaging film system[Nylon/PE/linear-low density polyethylene (LLDPE)] were investigated to improve the compatibility and toughness of these wastes using various compatibilizers such as ethylene vinylacetate (EVA), styrene-ethylene/butylene-styrene triblock copolymer (SEBS), styrene-ethylene/butylene-styrene-graft-maleic anhydride copolymer (SEBS-g-MA), polyethylene-graft-maleic anhydride (PE-g-MA), polypropylene-graft-maleic anhydride (PP-g-MA) , polyethylene-graft-acrylic acid (PE-g-AA) and polypropylene-graft-acrylic acid (PP-g-AA). Compared with simple melt blend system, the blends showed improvement of about $50\%$ increase in physical properties when SEBS and EVA were added. However, SEBS-g-MA thermoplastic elastomer which is highly reactive with amine terminal group of nylon, resulted in about $200\%$ increase in impact strength. This compatibilization effect resulted from the increase of interfacial adhesion and the reduction of domain size of dispersed phase in PP/Nylon blend system.

• Applied Biological Chemistry
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• v.33 no.1
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• pp.52-61
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• 1990

Fish protein was acylated with acetic anhydride(AA), succinic anhydride(SA) and maleic anhydride(MA) in order to improve the functional properties of the protein. The surface hydrophobicity and functional properties of protein were measured to study the relationship between them. It was found that the extented acylation of nucleophilic groups such as amino and sulfhydryl groups of the amino acid residues of fish protein was higher than other groups when acylated with AA, and the degree of acylation was 89.5 % for amino groups and 72.2 % for sulfhydryl groups. The surface hydrophobicity of fish protein was decreased by succinylation and maleylation, whereas acetylation caused tittle change. The acylated fish protein concentrate(FPC) showed higher surface hydrophobicity than the acylated fish myofibrilla protein(FMP). Acylation with AA, SA and MA of fish protein resulted in a significant increase in protein solubility, emulsifier properties, foaming properties, water adsorption capacity and oil adsorption capacity. These properties of acylated FMP were more improved than those of acylated FPC. Decrease in protein hydrophobicity was highly correlated with increase in protein solubility, and emulsifier properties and foaming properties were largely dependent on the solubility as well as surface hydrophobicity. The water adsorption capacity of the protein was significantly affected by solubility. Surface hydrophobicity had greater influence on oil adsorption capacity, whereas it had tittle effect on water adsorption capacity.

• Membrane Journal
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• v.24 no.1
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• pp.1-9
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• 2014

In this study, four soluble homo- and co-polyimides using 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (DOCDA) and 4,4'-diaminodiphenyl ether (ODA) monomers were synthesized to develop the gas separation membrane with good $CO_2/CH_4$ separation properties. To prepare the copolyimides, 20 mol% of three dianhydrides - (4,4'-(hexafluoroisoproplidene)diphthalic anhydride (6FDA), 4,4'-biphthalic anhydride (BPDA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) - were added in DOCDA-ODA monomer mixture, respectively. All the synthesized homo- and co-polyimides were characterized by FT-IR. Their thermal properties were analyzed with differential scanning calorimeter (DSC). Dense membranes were prepared from these copolyimides to check their gas permeation properties for $CO_2$ and $CH_4$ gases using a time-lag method. The permeation testing results are as follows; DOCDA/ODA homopolymer showed 1.71 barrer of $CO_2$ permeability and 74.35 of $CO_2/CH_4$ selectivity. The three polyimide copolymers (DOCDA/6FDA-ODA, DOCDA/BPDA-ODA, DOCDA/BTDA-ODA) showed lower $CO_2/CH_4$ selectivities and higher $CO_2$ permeabilities than the homopolymer (DOCDA-ODA). DOCDA/6FDA-ODA showed twice times higher $CO_2$ permeabilities without severe $CO_2/CH_4$ selectivity loss than the DOCDA-ODA.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.704-709
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• 1998

Non-linear optical polymer based on poly (${\alpha}$-methylstyrene-co-maleic anhydride) (MSMA) substrate polymer was prepared by polymer reaction method and its thermal and electro-optic properties were examined. In the polymer reaction between MSMA substrate polymer and 2-[4-(4-nitrophenylazo)-N-ethylphenylamino]ethanol (DR1) chromophore, the degree of substitution of DR1 into MSMA was higher with the 4-dimethylaminopyridine (DMAP) as catalyst and 3-dicyclohexyl carbodiimide (DCC) as dehydrating agent (sample, MSMA-DC) than the one with just 4-dimethylaminopyridine as catalyst (sample, MSMA-D). The synthesized NLO polymer (MSMA-DC) exhibited electro-optic coefficient of 18 pm/V (632.8 nm) and glass transition temperature ($T_g$) of about $175^{\circ}C$.