• 한국환경과학회지
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• 제16권8호
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• pp.865-872
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• 2007

The waterborne perfluoroacylic polyurethane composite (WFPUC) series were prepared by the emulsion polymerization (WFPUC-E) and the physical blending (WFPUC-B). WFPUC-E was prepared by polymerizing perfluoroalkyl ethyl acrylate (FA) and waterborne polyurethane (WPU), and WFPUC-B was prepared by blending FA copolymer and WPU. The structures of the synthesized WFPUC were identified by using FT-IR-ATR. The surface and thermal properties of the synthesized WFPUC were investigated by measuring contact angle, surface energy, and TGA. The surface energy of WFPUC-E was lower than that of WFPUC-B. The thermal stability of the WFPUC-B showed better than that of the WFPUC-E.

• 한국진공학회지
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• 제14권3호
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• pp.115-118
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• 2005

모델 고분자 미셀(서로 결합하거나, 결합하지 않는 두 경우)의 구조를 분석하기 위해 중성자 소각 산란(small angle neutron scattering)법을 이용하였다. 소수성 결합체의 응집수와 농도의 증가에 따른 정렬상태의 변화를 폴리에틸렌글라이콜(PEG, 6 K나 10 K고몰 분자량) 끝에 불화알킬그룹(pefluoroalkyl groups $(-(CH_2)_2C_OnF_{2n+1}$, (n = 6, 8,혹은 10)이 붙은 고분자용액을 이용하여 분석하였다. 결합체의 응집수는 소수성 말단기의 길이에 의해서만 주로 결정이 되고, 고분자의 농도나 온도에 의해 영향을 받지 않는다. 또한, 서로 결합하는 고분자 미셀과, 서로 결합하지 않는 고분자 미셀간에도 결합수에는 차이가 없다. 이러한 모델계는 농도가 증가함에 따라서 체심 입방구조로 정렬된다.

• 한국염색가공학회지
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• 제28권3호
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• pp.134-155
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• 2016

Perfluorinated chemicals are highly diverse and widely used. More than 160 substances are pre-registered under REACH and approximately 140 substances are in the existing chemicals list of Korea from this chemical group. Chemical structures of PFCs that are globally prohibited and still in uses are identified with OECD's classification of PFCs with an overall review on their uses in consumer products including textile products. Case examples for current domestic situation on use of PFCs as a major component of water-repelling agents in textile products as well as a brief summary of eight major PFC manufacturers' situation are presented from our survey study along the supply chains and the most recent report of EPA stewardship programme, respectively.

• 한국환경과학회지
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• 제13권10호
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• pp.947-953
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• 2004

Waterborne fluorinated acrylate copolymer (WFAC) for surface modification of textile was synthesized from perfluoroalkyl ethyl acrylate, octadecyl acrylate, glycidyl methacrylate, surfactant and 3,3 methyl-methoxy butanol. The structures of the synthesized WFAC were determinated by FT-IR and $^{19}F-NMR$ analysis. The thermal stability investigated with DSC and TGA was decreased with increasing the content of fluorinated acrylate in the copolymer. However, the particle sizes of WFAC were increased with increasing the content of fluorinated acrylate in the copolymer. The surface energies calculated by contact angles of WFAC were in the range of 29.80$\~$13.41 dyne/cm. On the observing SEM of the textile surface treated with WFAC, the textile was swollen and compacted with increasing the concentration of water repellency agent. WFAC synthesized in this study showed a good water repellency.

• Environmental Analysis Health and Toxicology
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• 제25권2호
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• pp.153-159
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• 2010

Perfluorooctane sulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) are the principal chemicals known as perfluoroalkyl acids (PFAs). Despite the widespread use of these compounds, relatively little is known about their fate and effects. The purpose of this study was to determine the toxic effects of PFOS and PFOA on Daphnia magna. In the acute toxicity test, D. magna were exposed for 48 hours at concentrations of 0, 30, 45, 67.5, 101.25 and 151.88 mg/L PFOS, and 0, 100, 160, 225, 337.5 and 506.25 mg/L PFOA, respectively. In the case of chronic toxicity test, D. magna were exposed through water for 21 days at concentrations of 0, 0.375, 0.75, 1.5, 3 and 6 mg/L PFOS, and 0, 1.25, 2.5, 5, 10 and 20 mg/L PFOA, respectively. Acute toxicity was assessed on the basis of immobility, while chronic toxicity was assessed on the basis of fecundity. The acute toxicity test on PFOS and PFOA showed that the values of $EC_{50}$ were 50.90 mg/L and 253.47 mg/L, respectively. In the chronic test, fecundity was reduced significantly at 1.5 mg/L of PFOS and 10 mg/L of PFOA, respectively. These results indicated that PFOS is more toxic to zooplankton than PFOA, and both chemicals have some hazard demonstrates risk for acute or chronic toxicity to freshwater organism.

• 대한수의학회지
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• 제48권3호
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• pp.347-355
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• 2008

Perfluorooctanoic acid (PFOA), a member of the perfluoroalkyl acids that have wide commercial applications, is persistent organic pollutants widely spread throughout the environment and human population. But little is known about the adverse biological effects of the PFOA. In the present study, the toxicological effects of PFOA were investigated in rats. Sprague-Dawley rats (N = 10 in each group) were orally administered with PFOA in drinking water for 4 weeks (0, 100, 200, or 400 ppm in male, and 0, 200, 400, or 800 ppm in female). Three female rats given 800 ppm died during the study. PFOA treatment decreased the body weight gain and increased the liver weights in both genders. Serum biochemical investigations revealed significant increases in the aspartate aminotransferase, alanine transaminase, alkaline phosphatase, blood urea nitrogen, total cholesterol, and total bilirubin in male but in female. Serum estradiol (E2) levels were increased in all treated rats. Histopathologically, hepatocellular hypertrophy around central vein was noted in the liver of treated rats. No significant histopathological changes were noted in other organs. In conclusion, PFOA induced toxicological changes in the liver and increased serum E2 level which was not related to histopathological changes of endocrine and reproductive system.

• Composites Research
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• 제30권1호
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• pp.41-45
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• 2017

Magnetite nanoparticles were synthesized by adding an ammonium hydroxide to a mixed solution of iron (II) and (III) chlorides. A silicon surfactant of ${\alpha},{\omega}$-(3-aminopropyl)polydimethylsiloxane was adsorbed on the particles as dispersant and a polydimethylsiloxane polymer was used to prepare ferrofluids of silicone oil base. Fluorinated surfactants of anionic ammoniated perfluoroalkyl sulfonamide and nonionic fluoroaliphatic polymeric esters were applied to the particles and a perfluoropolyether was used to prepare ferrofluids of fluorine oil base. The experimental conditions were used for preparing the ferrofluids with concentrations of 200, 300 and 400 mg/mL, and density, magnetization and viscosity of the products were characterized. The density values increased in proportion to the concentration, indicating 1.11-1.27 g/mL for silicone-oil-based fluids and 1.95-2.10 g/mL for fluorine-oil-based fluids in the range of 200-400 mg/mL. The saturation magnetization of the silicone-oil-based and fluorine-oil-based fluids indicated 14.7, 24.4, and 30.7 mT and 15.8, 23.3, and 33.7 mT for 200, 300, and 400 mg/mL, respectively, depending on the content of magnetic particles in the fluid. The viscosity of the silicone-oil-based ferrofluids was highly stable compared to that of the fluorine-oil-based with increasing temperatures. The ferrofluids are usually applied to seals and speakers with the silicone base and to seals with the fluorine base.

• 폴리머
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• 제26권1호
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• pp.9-17
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• 2002

탄화수소의 수소 부분이 불소로 치환된 과불소알킬기(perfluoro group : $CF_3(CF_2)_nCH_2CH_2$-; n=5, 7, 9, 11)를 함유하고 있는 perfluoroalkylethyl acrylate(FA)와 styrene을 bulk 상태에서 $60^{\circ}C$를 유지하며 $\alpha$, $\alpha$'-azobisisobutyronitrile(AIBN)을 개시제로 하여 각각의 단량체의 반응 몰비를 변화시키며 전환율을 10% 이내로 제한하여 공중합체를 합성하였다. 또한 반응 몰비의 변화에 따른 중합된 공중합체내의 반복단위의 함량사이의 관계와 Helen-Tudos법을 이용하여 단량체 반응성비 $r_1$, $r_2$를 구하였다. FT-IR과 $^1H-NMR$을 통해 두 단량체의 공중합 여부와 구조를 정성적으로 확인하였고 공중합체의 조성은 $^1H-NMR$분석을 통해 구하였다. 단량체의 비율에 따른 열적 특성은 DSC와 TGA를 통하여 분석하였으며 공중합체와 소량의 공중합체가 첨가된 PMMA의 접촉각을 측정하여 공중합체의 표면특성을 나타내는 표면자유에너지를 계산하였다.

• 청정기술
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• 제5권2호
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• pp.37-44
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• 1999

불소 함유 디올(diol)과 친수성기 함유 디올을 사용하여 수용성 불소계 폴리우레탄을 합성하여, 반응물의 조성이 합성된 폴리우레탄의 대표적 물성인 표면자유에너지와 수분산성에 미치는 영향을 조사하였다. 폴리올보다 이온성부여 디올이 분산성 향상에 효과적이었으며, 전체 폴리올(polyol)에 대한 이온성 친수성기 함유 디올의 몰 비가 0.3~0.7의 범위를 가질 때, 합성된 폴리우레탄의 수용액에 분산된 입자 지름이 610~310nm로 안정된 유화물을 형성하였다. 폴리우레탄내의 불소 함량이 10 wt%까지 증가함에 따라 표면자유에너지는 22.3 dyn/cm에서 12.6 dyn/cm로 급격히 감소하였으며, 수분산된 입자의 지름은 380 nm에서 860nm로 증가하였다. 그 이유는 낮은 표면에너지와 강한 소수성을 갖는 불소집합체의 표면 배열로써 분자 상호간의 결합력이 증가하기 때문이다. 과불소알킬기를 포함하는 매크로단량체(macromonomer)의 강한 소수성 때문에 수용성 폴리우레탄의 단점인 소수성 하락의 보완에 더 효과적이었다.

• Journal of Applied Biological Chemistry
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• 제63권3호
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• pp.243-248
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• 2020

The long-chained perfluoroalkyl acids (PFAAs), perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are a potential exposure risk in the environment, specifically for humans due to high levels of bioaccumulation, persistence, and toxicity. In the current study, the plant uptake factors (PUFs) of spinach and Welsh onion were investigated on the three different concentration levels of PFOA and PFOS in soil. Spinach and Welsh onion were divided into three residue groups, a control group and two levels of PFOA and PFOS. The PFAAs spiked soils were aged for six months and the extractable residue of PFOS in the aged soil was reduced to 30-59% of the initial spiked concentrations for PFOS, while PFOA showed almost the same initial spiked concentrations. The PUFs for PFOA and PFOS were 0.111-2.821 and 0.047-3.175 for spinach, and 0.203-0.738 and 0.035-0.181 for Welsh onion, respectively. The highest PUF values in both vegetable were displayed when the residual concentration of PFAAs were part-per-billion (ppb) or sub-ppb in soil.