• Proceedings of the Korean Fiber Society Conference
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• 2007.11a
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• pp.97-100
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• 2007

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• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1071-1076
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• 2009

N,N,N′,N′-tetramethylethylenediamine (TMEDA) acts as a simple, mild and efficient catalyst for the acylation of alcohols, phenols and thiols at room temperature under solvent-free condition. Acylation reaction with acetic anhydride and benzoic anhydride proceeds with good to excellent yield in the presence of TMEDA as the catalyst.

• Elastomers and Composites
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• v.58 no.1
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• pp.26-31
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• 2023

Aromatic diamine containing ortho catenation and methyl group was synthesized from 4-methyl catechol and 4-nitrobenzoyl chloride. Subsequently, a poly(amic acid) was prepared by reacting 4-methyl-1,2-phenylene bis(4-aminobenzoate) with 4,4'-hexafluoroisopropylidenediphthalic anhydride (6FDA). The resulting poly(amic acid) was transformed into a polyimide through chemical imidization. The polyimide formed was soluble in N-methyl-2-pyrrolidone (NMP) and could be cast into a flexible, transparent film. Furthermore, the polyimide exhibited a 5% weight loss at 380 ℃ in the nitrogen atmosphere.

• Polymer(Korea)
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• v.29 no.6
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• pp.593-598
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• 2005

This work studied the loading capabilities and release behaviors of poly(ethylene-alt-maleic anhydride) (PEMAh)/poly(4-vinyl pyridine) (P4VP) multilayer films formed by the layer-by-layer(LbL) sequential self-assembly method, using Rodamine 6G(R6G) as an indicator. Thickness of the multilayer, and loading and subsequent release behavior of R6G from the multilayer were studied using UV-visible spectroscopy. The amount of R6G loaded in multilayer film increased linearly with increasing film thickness. pH-Sensitive permeability was observed, where lower pH environments increased both release rate and release amount. By additional assembling of PEMAh/poly(ethyleneimine) (PEI) capping layers on top of (PEMAh/P4VP)n multilayers, the release of R6G was better controlled.

• The Korea Journal of Herbology
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• v.23 no.2
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• pp.51-58
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• 2008

Objectives : Trimellitic anhydride (TMA), a sensitizer that induces occupational asthma and atopic dermatitis, is widely used industrially to make epoxy and alkyd resins, plasticizers, high temperature polymer, and surfactants. The aim of this study was to investigative the effects of aqueous extracts of Lonicera japonica Flower(LJFAE) on TMA-induced contact hypersensitivity (CHS) in Balb/c mice. Methods : The dried flowers of L. japonica were extracted with distilled water at $100^{\circ}C$ for 7 h. The extract was freeze-dried following filteration through 0.45 ${\mu}m$ filter. Mice were orally administrated with or without LJFE of a different doses(25-100 mg/kg) for 28 days. In the challenge period, mice were externally applied at difference doses of LJFAE one time per day 30 min before TMA treatment. We examined the effects of LJFAE on the the serum levels of IgE and prostagladin E2 (PGE2), the Thl/Th2 cytokine production of spleen cells, ear swelling responses, and the leukocyte infiltration induced by TMA. Results : The orally and externally administration of LJFAE dose-dependently reduced the serum levels of IgE and PGE2 production as well as ear swelling responses and leukocyte infiltration in TMA-induced Balb/c mice. Furthermore, the levels of Thl (TNF-${\alpha}$, IFN-${\gammer}$, IL-2)/Th2 (IL-4, IL-5, IL-13) cytokine production from spleen cells stimulated with anti-CD3 and CD28 mAbs was markedly suppressed by the orally and externally treatment with LJFAE in a concentration dependent manner. Conclusions : These results suggest that LJFAE suppresses the inflammatory mediators and regulates the Thl/Th2 cytokines. Therefore, these properties may contribute to the strong anti-CHS response effect of LJFAE.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2A
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• pp.137-143
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• 2011

This study evaluated the effects of maleic anhydride grafted polypropylene powder (mPP) contents on the bond properties of cement mortar and nonpolar macro synthetic fibers (macro synthetic fiber). Dog-bone bond tests were performed to evaluate the bond performance of macro synthetic fiber in cement mortar with varying amounts of mPP (0%, 5%, 10%, 15%, 20%, 25%, 30% of cement weight). The bond properties (pullout behavior, pullout load and interface toughness) of macro synthetic fiber in cement mortar increased as the mPP contents was increased. The bond properties increased with the mPP contents. The microstructure of macro synthetic fiber surface was examined after the pullout test to analyze the frictional resistant force according to mPP contents during the pullout process of macro synthetic fiber in cement mortar. The scratched of macro synthetic fiber increased with the mPP contents.

• Resources Recycling
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• v.23 no.1
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• pp.48-57
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• 2014

In this study, we have investigated the influence of the nature of solvent on the grafting reaction of maleic anhydride onto polyethylene wax obtained as a by-product in a high density polyethylene plant. The results show that the grafting ratio in xylene as a solvent was higher than toluene. This is because xylene has excellent monomer solubility, swelling property and miscibility. It has been also observed that grafting degree shows an initial jump in percentage of grafting with increasing amount of solvent, from 0% v/w to 200% v/w giving maximum grafting in 200% v/w and then slightly decreases on further increase in the amount of solvent and becomes almost constant. It can be also seen that gel content was not formed under the use of solvent. It means that solvent prevented cross-linking reaction due to chain transfer reactions to solvent molecules. Studies of melt viscosity at $140^{\circ}C$ showed that viscosity increased after grafting of maleic anhydride onto polyethylene wax.

• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.866-871
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• 1997

The com starch was treated with propylene oxide, 1,2-epoxybutane, glycidyl methacrylate, maleic anhydride, caprolactone, respectively, in order to alter the hydrophilicity and the reactivity of starch. When the starch was not dried, poor reaction was observed except the reaction with propylene oxide or maleic anhydride. The treated starches were grafted with styrene by several different polymerization methods. Solution polymerization and redox polymerization using cerium(IV) ion show poor grafting efficiency and poor yield. Encapsulation of starch with polystyrene by suspension polymerization was difficult due to the hydrophilicity of the starch. Among the examined methods, emulsion polymerization was found to be the suitable way to graft styrene onto starch.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.979-984
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• 1999

Aromatic soluble polyimides were synthesized from 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and various dianhydrides such as pyromelltic dianhydride(PMDA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride(BTDA), and 4,4'-(hexafluoroisopropylidene)-bis(phthalic anhydride)(6FDA). Polyimides prepared by thermal imidization were insoluble in common organic solvents (acetone, MNP, DMAc, DMSO, THF, and DMF) but those prepared by chemical imidization were soluble. The difference of solubility was explained by esterification between hydroxyl group and $CH_3COO^-$ from acetic anhydride used as a dehydration agent in chemical imidization. Glass transition temperatures of polyimides by thermal method were higher than those by chemical method. All of the polyimides are stable up to $300^{\circ}C$ regardless of the sample preparation. The x-ray diffraction patterns showed that all polyimides were amorphrous.

• Journal of Environmental Health Sciences
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• v.2 no.1
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• pp.37-48
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• 1975

Air pollutants were measured to get useful data in preventing and controlling the pollution at industrial and semi-industrial, commercial, cross-road and residential areas by season in Busan from September 1973 to June 1974. Teated were dustfalls(ton/$km^2$/month)by Deposit Gauge method, sulfuric anhydride(mg $SO_3/day/100cm^2 PbO_2$) by Lead Peroxide candle method. The relations between pollution and metherologlcal factors and source of pollution were discussed, The findings are as follows: 1. The mean value of dustfalls was 24.8 tons rangi~ng from 12.5 tons to 44.5 tons. The highest amount of dustfalls of 29.0 tons was measured in crossroad areas while the 1oeest of 22.7 tons in commercial areas, and Winter the highest of 27.7 tons while in Spring the lowest of 21.2 tons. 2. The mean value of water soluble substances was 31.7 per cent, and seasonal variation of pH was shown as 4.20 in Autumn, 3.85 in Summer and 2.76 in Winter. 3. The mean value of sulfuric anhydride was 1.54mg ranging from 0.197mg to 4.162 mg. The highest concentration of sulfuric anhydride of 2.03mg was detected in cross-road areas while thelowest of 1.23mg in residential areas, and Summer the highest of 2.18mg while in Spring the lowest of 1.09mg(0. 92mg in Nov. 1973) 4. Dustfalls are more with the decreased of relative humidity and precipitation while concentrat:on of sulfuric anhydrides are more with the increased of relative humidity. 5. There is a probability of occuring chronic symptoms(respiratory and others) as the dustfalls with 24.8 tons and sulfuric anhydride with 1.54mg in Busan. According to this, it is the time to discuss monitoring system and systematic preventing methods.