• Environmental Analysis Health and Toxicology
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• v.18 no.3
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• pp.199-208
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• 2003

A new technique was proposed for the determination of alkylphenols, chlorophenols and bisphenol A in tap water samples. The sample preparation consists of a solid phase extraction (SPE) of alkylphenols, chlorophenols and bisphenol A from a water sample with XAD-4 and subsequent conversion to isobutyloxycarbonyl (isoBOC) derivatives or tert-butyldimethylsilyl (TBDMS) derivatives for sensitive analysis with the CC/MS SIM mode. The recoveries were 86.6 ∼ 105.2％ (isoBOC derivatization) and 97.6∼484.5％ (TBDMS derivatization), respectively. The limit of quantitation of alkylphenols, chlorophenols and bisphenol h for SIM were 0.001∼0.050 $\mu\textrm{g}$/1 (isoBOC derivatization) and 0.003∼0.050 $\mu\textrm{g}$/1 (TBDMS derivatization). The SIM responses were linear with the correlation coefficient varying 0.9755∼0.9981 (isoBOC derivatization), and 0.9908∼0.9996 (TBDMS derivatization). When these methods were applied to tap water samples, the range of concentrations were 22.8∼31.3 ng/1 in 2,4-dichlorophenol, 28.6∼70.3 ng/1 in pentachlorophenol, 15.2∼17.4 ng/1 in t-butylphenol, 10.8∼13.2 ng/1 in t-octylphenol and 17.6∼36.3 ng/l in bisphenol A, respectively.

• Analytical Science and Technology
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• v.13 no.3
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• pp.282-290
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• 2000

In this study, polymer additives were extracted and separated by Soxhlet extraction method and the dissolution-precipitation method from a polycarbonate (optical grade) which completely absorbed UV light below 390 nm. Analytical techniques such as UV-Vis spectroscopy, FT-IR, and HPLC were applied to analyze additives in polycarbonate. Separated materials from the polycarbonate may be a complex mixture containing additives such as UV stabilizer, antioxidants (primary and secondary), monomers, and oligomers. Several compounds such as bisphenol A, Irganox 1010, and Cyasorb UV-5411 were identified by chromatograms and UV spectra obtained from RP HPLC analysis using Bondapak $C_{18}$ column, methanol mobile phase, and a photodiode array (PDA) detector. Also, the content of UV-5411 in the polycarbonate was about 0.12 wt% by a quantitative analysis through UV spectroscopy.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.149-154
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• 1999

FRMLs(Fiber Reinforced Metal Laminates) is a new type of hybrid materials. FRMLs consists of high strength metal and fiber which are laminated using a structural adhesive bond(epoxy resin). The effect of resin mixture ratios on the fatigue crack propagation behavior and mechanical property of Aramid fiber reinforced aluminum composites was investigated. The epoxy, diglycidylether of bisphenol A(DGEBA) was cured with methylene dianiline(MDA) with or without accelerator(K-54). Eight kinds of resin mixture ratio were tested for the experiment ; five kinds of FRMLs(1))epoxy & curing agent) and three kinds of FRMLs(2)(epoxy & curing agent & accelerator). FRMLs(2) have a more effective characteristics on the fatigue crack propagation behavior and mechanical property than FRMLs(1)

• Journal of Environmental Science International
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• v.31 no.1
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• pp.23-31
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• 2022

As a herbal supplement, Dioscorea batatas Decne (DBD) presents potent antioxidant activity and diverse health benefits. In the present study, functions of a 30 kDa glycoprotein isolated from DBD (hereafter, DBD glycoprotein) in the regulation of feed efficiency and fecal malodor in mice were explored. DBD glycoprotein produced protective effect against cytotoxicity induced by the ecotoxicological endocrine-disrupting substance bisphenol A in gastrointestinal epithelial HT-29 cells. To investigate its potential roles in the regulation of feed efficiency and fecal malodor, mice were administered an oral injection of DBD glycoprotein for 2 weeks. Compared with the control values, the weight of internal organs (liver, heart, kidney, and spleen) and levels of glutamate pyruvate transaminase, glutamate oxaloacetate transaminase, and lactic dehydrogenase were not significantly changed during DBD glycoprotein administration for 2 weeks. Interestingly, DBD glycoprotein improved feed efficiency and reduced hydrogen sulfide concentration without altering the ammonia level in mouse feces. Collectively, these results indicate that DBD glycoprotein is a functional agent that exerts gastrointestinal protective effects against ecotoxicological substances, improves feed efficiency, and reduces fecal malodor.

• Environmental Analysis Health and Toxicology
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• v.18 no.1
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• pp.45-55
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• 2003

The alkylphenols, chlorophenols and bisphenol A were determined by gas chromatography/mass spectrom-etry-selected ion monitoring (GC/MS-SIM) mode followed by two work-up methods for comparison; isoBOC derivatization method and TBDMS derivatization method. Eleven phenols in paper samples were extracted with acetonitrile. Also, solid -phase extraction (SPE) with XAD -4 and subsequent conversion to isobutoxycarbonyl derivatives or tert.-butyldimethylsilyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode. The SIM responses were linear with the correlation coefficient varying 0.9717 ∼ 0.9995 (isoBOC derivatization), and 0.9842 ∼ 0.9980 (TBDMS derivatization). The recoveries were 82.4 ∼ 108.8％) by area ratio of phenanthrene -d$\_$10/ vs bisphenol A-d$\^$l6/. (isoBOC derivatization and TBDMS derivatization) The range of concentrations was respectively, 0.95 ∼ 1.44 ng/g in 2,4-dichlorophenol, 1.01 ∼ 1.17 ng/g in t-butylphenol,2.17 ∼ 5.84 ng/g in pentachlorophenol, 12.68 ∼ 14.88 ng/g in nonylphenol and 30.84 ∼ 153.72 ng/g in bisphenol A.

• Textile Coloration and Finishing
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• v.24 no.1
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• pp.33-38
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• 2012

In this study, to increase flame retardation of poly(ethylene terephthalate) (PET) in burning, bisphenol A bis(diphenyl phosphate) (BDP), a well known flame retardant containing phosphorous, was reacted on end groups of PET by radical pathway. End-capping mechanism of PET with BDP was suggested and confirmed by spectroscopic and thermal analysis. From 400 MHz $^{31}P$ solid state FT-NMR spectrum of end-capped PET (PET-BDP), phosphorus spectra peak in BDP was found at ca. -20 ppm. Furthermore, P-C bond stretching vibration peaks were found ca. $600cm^{-1}$ in FT-IR spectrums of PET-BDP. These results showed that BDP can be chemically added on end groups of PET by our method. Thermal characteristics of pure PET (pPET) and PET-BDP were measured and evaluated by TGA analysis. There was not significant changes in thermal characteristics of PET-BDP compared to that of pPET.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.55-59
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• 2009

The epoxy resin without hardener can harden by a ring-opening reaction in the presence of the alkalies produced by the hydration of cement in epoxy-modified mortars and concretes. This paper investigates the effect of curing conditions on the strength improvement of polymer-modified mortars using bisphenol A-type epoxy resin without hardener. The polymer-modified mortars using epoxy resin are prepared with various polymer-cement ratios, and subjected to ideal, water, dry and heat cures. In the heat cure, the epoxy-modified mortars are sealed or unsealed with a PVDC (polyvinylidene chloride) film. The epoxy-modified mortars are tested for flexural and compressive strengths at desired curing methods. The microstructures of the epoxy-modified mortars are also observed by scanning electron microscope. The effects of curing conditions on the strength development of the epoxy-modified mortars are examined. From the test results, the marked effectiveness of the heat cure under the PVDC film sealing against the development of the strength of the epoxy-modified mortar without the hardener is recognized. The flexural and compressive strengths of 7-day-90℃ heat-cured, PVDC film-sealed epoxy-modified mortars without hardener reach 7 to 17MPa and 24 to 44MPa respectively, and are two to three times of Unmodified mortar. Such high strength development of the epoxy-modified mortars may be achieved by the dense microstructure formation by cement hydrates and the hardening of the epoxy resin in the mortars.

• Polymer(Korea)
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• v.25 no.2
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• pp.208-217
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• 2001

PET/BPA copolymer of terephthalic acid, bisphenol-A and ethylene glycol was melt-pressed and quenched in ice water. This copolymer film was drawn by capillary rheometer. Shrinkage, crystallinity, morphology, thermal, dynamic mechanical, and mechanical properties of these copolymer films were investigated. The PET/BPA copolymer film exhibited T$_{m}$ lower than that of PET film. The crystallinity and density of these drawn copolymer films increased with draw ratio and draw rate but decreased with draw temperature. The tensile strength and tensile modulus of the copolymer films increased with draw ratio but decreased with draw temperature. Shrinkage of the drawn copolymer film decreased with draw ratio and draw rate.e.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.5 no.2
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• pp.77-83
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• 1991

In this study the investigation were carried out on short-term breakdown characteristics of the compound material dependent on change of filler quantity, ambient temperature(room temperature~[$190[^{\circ}C$]) and kinds of voltage sources for the compound materials of Bisphenol- A epoxy resins filled with $SiO_2$ particles. As the results, obtained the dielectric breakdown strength generally decrease as increasing the quantity of filler and the distance, spacing of each's particles, decrease as increasing the quantity of filler, when the distance is less than [$7.5\mu\textrm{m}$], dielectric breakdown strength is nearly constant. In the case on AC voltage dielectric strength of filled epoxy resins is stronger than nonfilled epoxy resins on temperature region more than $130[^{\circ}C$].

• Journal of Environmental Health Sciences
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• v.45 no.1
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• pp.18-29
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• 2019

Objectives: The purpose of this study was to examine the relationship between urinary bisphenol A concentration and allergic diseases in children. Methods: This study was conducted in Seoul, South Korea. We collected urine samples from 231 children from a single elementary school in June 2014. Among these, 69 children with urinary creatinine levels outside the normal range were excluded. Information on allergic diseases was obtained from the parents of the children. Urinary bisphenol A was analyzed using a liquid chromatography tandem mass spectrometer. Logistic regression analysis was used to determine if allergic disease was affected by urinary bisphenol A concentration. Results: Girls had a significantly higher concentration of urinary bisphenol A than did boys (p<0.05). Children of 10-12 years old had a significantly higher concentration of urinary bisphenol A than did children 7-9 years old (p<0.01). Concentration of urinary bisphenol A was increased from underweight to overweight (p<0.05). As the concentration of urinary bisphenol A was increased by $1{\mu}g/L$ or $1{\mu}g/g$ creatinine, the risks of lifetime symptoms of atopic dermatitis in children was 1.22 times (95% CI; 1.05-1.41) or 1.08 times (95% CI; 1.01-1.15). Conclusion: Concentration of urinary bisphenol A was associated with gender, age, body mass index, and allergic disease. Particularly, urinary bisphenol A concentration was associated with lifetime symptoms of atopic dermatitis. The findings of this study could contribute to the management of health effects among sensitive groups such as children.