• Journal of Food Hygiene and Safety
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• v.28 no.1
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• pp.56-62
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• 2013

Poly (ethylene naphthalate) (PEN), which is likely to be widely used in various application due to good barrier properties, is manufactured by condensation polymerization of 2,6-dimethylnaphthalene dicarboxylate (2,6-NDC) or 2,6-naphthalene dicarboxylic acid (2,6-NDA) with ethylene glycol. In this study, an analytical method to determine monomers in food simulants, which might migrate from PEN food contact materials into food, was developed. The HPLC-UV method was validated for 2,6-NDC and 2,6-NDA. The obtained validation parameters were selectivity, sensitivity, linearity, precision and recovery. The simultaneous HPLC method was considered the be most effective analytical method to determine 2,6-NDC and 2,6-NDA in food simulants.

• Fibers and Polymers
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• v.1 no.2
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• pp.116-121
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• 2000

It has been considered that malic acid, $\alpha$-hydroky succinic acid, could not form crosslinks in the cellulosic materials unless activated by other polycarboxylic acids such as butanetetracarboxylic acid or citric acid because there are only two carboxylic acids per molecule available fur the formation of one anhydride intermediate. However we found that the dicarboxylic malic acid with sodium hypophosphite catalyst without the addition of other crosslinkers was able to improve wrinkle resistance of cotton up to $294^{\circ}$(dry WRA) and $285^{\circ}$ (wet WRA), which is a measure of crosslinking level in cotton. $^1$H FT-NMR, FT-IR and GPC analysis indicated the in-situ formation of an trimeric $\alpha$, $\beta$-rnalic acid with a composition of 1:3 through the esterification between hydroxyl group and one of carboxylic groups in malic acid during curing. The crosslinking of cotton was attributed to the trimeric $\alpha$, $\beta$-malic acid, a tetracarboxylic acid, which can form two anhydride rings during curing. The influence of crosslinking conditions such as concentrations of malic acid and catalyst, pH of the formulation bath, and curing temperature were investigated in terms of imparted wrinkle resistance and whiteness. The addition of reactive polyurethane resin in the formulation slightly increased the mechanical strength retention of crosslinked fabric coupled with additional increase in wrinkle resistance.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.443-446
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• 2002

일반적으로 결정성 고분자의 모폴로지 형태 및 결정화정도는 고분자 물질의 물리적 성질에 매우 큰 영향을 미치므로 결정화과정에 관한 연구는 고분자 물질의 공정-구조-물성의 상호관계를 이해하는데 매우 중요하다. Poly(trimethylene 2,6-naphthalate) (PTN)은 1,3-propanediol 과 2,6-naphthalene dicarboxylic acid로 합성된 결정성 고분자이며 1969년에 Doling 와 Chester에 의하여 처음으로 합성방법이 발표되었다$^1$. 그러나 1,3-propanediol의 공업적 합성이 이루어진 최근에서야 이 물질을 이용한 고분자의 연구가 활발하게 진행되게 되었다. (중략)

• Bulletin of the Korean Chemical Society
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• v.29 no.12
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• pp.2383-2389
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• 2008

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.264-266
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• 2009

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.47-47
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• 2000

• Archives of Pharmacal Research
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• v.16 no.1
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• pp.78-81
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• 1993

Solution equilibria of the thmary systems $UO_2(II)$, La(III), Ce(III)-N-(2-acetamido)-iminodiacetic acid and dicarboxylic amino acids are studied potentiometrically. The formation of 1:1:1 mixed ligand complexes are inferred from the potentiometric titration curves. The formation constants of the different binary and thmary complexes in such system are evaluated at t=$24\pm{0.1}^\circ{C}\;and\;\mu=0.1\;mol\;dm^{-3}(kNO_3)$. It is deduced that the temary complex is more stable than the corresponding binary amino acid anion complex. Moreover, the order og stability of the binary or temary complexes in terms of nature of amino acid and metal ion is investigated and discussed.

• Journal of the Korea Concrete Institute
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• v.18 no.4 s.94
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• pp.569-576
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• 2006

PC-type copolymers were synthesized using MPEG(polyethylene glycol methyl ether methacrylate, Mn=2080) to different mole ratios of mono-carboxylic acid(AA : acylic acid). The mole ratios of AA were 2, 3, 4 and PC-type terpolymers were synthesized using mono-, dicarboxylic acid(ITA : itaconic acid MAL : maleic acid) with the same graft chain. To investigate effects of PC-type co-, ter-polymers on the hydration of cement experiments involving FT-IR, XRD, DSC, SEM have been analysed with cement paste specimens to 1, 3, 28 day. The hydration reaction rate of cement paste was slightly delayed at 1 day, due to increase in molar ratio of [AA]/[MPEG], it was recovered in the days after and the copolymer was more active than the terpolymer, because of low carboxylic acid content PC-type copolymers applied 2AA-type were fastest copolymer on hydration reaction of cement paste to 3 day and the more AA mole ratios increased, the more hydration was retarded.

• Journal of the Korean Chemical Society
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• v.45 no.6
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• pp.507-512
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• 2001

The hydrothermal reaction between lanthanum(Ⅲ) nitrate $(La(NO3)3${\cdot}$6H_2O)$ and benzene-1,3-dicarboxylic acid $(H_2BDC)$ in the presence of 1,2-bis(4-pyridyl)ethane gave a 2-D lanthnum-BDC coordination polymer with an empirical formula of $〔La_4$(BDC)_6(H_2O)_5$〕(H_2O)$ (1). X-ray structure analysis of compound 1 revealed that this polymer contains four distinct La metals. The three La metals are 7-coordinate with three different structures: a capped trigonal prism, a capped octahedron, and a pentagonal bipyramid. The remaining La metal has a 8-coordinate, square antiprismatic structure.

• Asian Journal of Atmospheric Environment
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• v.6 no.1
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• pp.67-72
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• 2012

The chemical characterization of water-soluble organic carbon in ash emitted from a coal combustion boiler has not been reported yet. A total of 5 ash samples were collected from the outlet of an electrostatic precipitator in a commercial 500 MW coal-fired power plant, with their chemical characteristics investigated. XAD7HP resin was used to quantify the hydrophilic and hydrophobic water-soluble organic carbons (WSOC), which are the fractions of WSOC that penetrate and remain on the resin column, respectively. Calibration results indicate that the hydrophilic fraction includes aliphatic dicarboxylic acids and carbonyls (<4 carbons), amines and saccharides, while the hydrophobic fraction includes aliphatic dicarboxylic acids (>4-5 carbons), phenols, aromatic acids, cyclic acid and humic acid. The average mass of the WSOC in the ash samples was found to depend on the bituminous coal type being burned, and ranged from 163 to 259 ${\mu}g$ C/g of ash, which corresponds to 59-96 mg C of WSOC/kg of coal combusted. The WSOC mass accounted for 0.02-0.03 wt% of the used ash sample mass. Based on the flow rate of flue gas produced from the combustion of the blended coals in the 500 MW coal combustion boiler, it was estimated that the WSOC particles were emitted to the atmosphere at flow rates of 4.6-7.2 g C/hr. The results also indicated that the hydrophilic WSOC fraction in the coal burned accounted for 64-82% of the total WSOC, which was 2-4 times greater than the mass of the hydrophobic WSOC fraction.