• Title, Summary, Keyword: formaldehyde

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Modification of Soy Protein Film by Formaldehyde (Formaldehyde 처리에 의한 대두단백 필름의 물성 개선)

  • Rhim, Jong-Whan
    • Korean Journal of Food Science and Technology
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    • v.30 no.2
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    • pp.372-378
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    • 1998
  • Two types of formaldehyde-treated soy protein isolate (SPI) films, formaldehyde-incorporated and formaldehyde-adsorbed films, and control SPI films were prepared. Cross-linking effect of formaldehyde on selected film properties such as color, tensile strength (TS), elongation at break (E), water vapor permeability (WVP), and water solubility (WS) were determined. Physical properties of formaldehyde-incorporated films were not geneally different from those of control films, while almost all of those among formaldehyde-adsorbed films were significantly different. Through cross-linking development within formaldehyde-adsorbed films, WS decreased significantly (P<0.05) from 26.1% to 16.6%, and TS increased two times while E decreased two times compared with control films. This was caused by insolubilization and hardening of protein by cross-linking most likely attributed to the significant changes in properties of protein films reacted with formaldehyde.

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Isoconversional Cure Kinetics of Modified Urea-Formaldehyde Resins with Additives

  • Park, Byung-Dae
    • Current Research on Agriculture and Life Sciences
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    • v.30 no.1
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    • pp.41-50
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    • 2012
  • As a part of abating formaldehyde emission of urea-formaldehyde resin, this study was conducted to investigate the rmalcure kinetics of both neat and modified urea-formaldehyde resins using differential scanning calorimetry. Neat urea-formaldehyde resins with three different formaldehyde/urea mol ratios (1.4, 1.2 and 1.0) were modified by adding three different additives (sodium bisulfite, sodium hydrosulfite and acrylamide) at two different levels (1 and 3wt%). An isoconversional method at four different heating rates was employed to characterize thermal cure kinetics of these urea-formaldehyde resins to obtain activation energy ($E{\alpha}$) dependent on the degree of conversion (${\alpha}$). The $E{\alpha}$ values of neat urea-formaldehyde resins (formaldehyde/urea = 1.4 and 1.2) consistently changed as the ${\alpha}$ increased. Neat and modified urea-formaldehyde resins of these two F/U mol ratios did show a decrease of the $E{\alpha}$ at the final stage of the conversion while the $E{\alpha}$ of neat urea-formaldehyde resin (formaldehyde/urea = 1.0) increased as the ${\alpha}$ increased, indicating the presence of incomplete cure. However, the change of the $E{\alpha}$ values of all urea-formaldehyde resins was consistent to that of the Ea values. The isoconversional method indicated that thermal cure kinetics of neat and modified urea-formaldehyde resins showed a strong dependence on the resin viscosity as well as diffusion control reaction at the final stage of the conversion.

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Optimum Conditions of Formaldehyde Degradation by the Bacterium Pseudomonas sp. YK-32 (세균 Pseudomonas sp. YK-32 균주에 의한 Formaldehyde 분해 최적조건)

  • Kim, Young-Mog;Lee, Yun-Kyoung;Kim, Kyoung-Lan;Lee, Eun-Woo;Lee, Myung-Suk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.2
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    • pp.102-106
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    • 2008
  • Formaldehyde, an indoor volatile organic compound, is considered toxic due to its carcinogenic risk. Recently, we isolated a formaldehyde-degrading bacterium Pseudomonas sp. YK-32. A crude enzyme prepared from YK-32 also degraded formaldehyde, suggesting that YK-32 cells have formaldehyde hydrogenase activity which is one of the important factors in formaldehyde degradation. The formaldehyde hydrogenase activity was increased 1.25 fold by adding 0.1 % glucose and formaldehyde to the culture medium. In addition, treatment with 1 mM EDTA as a permeabilizer promoted the degradation of formaldehyde and increased the enzymatic activity.

Indoor and Outdoor Formaldehyde Concentrations in Underground Environments (실내외 포름안데히드 농도에 관한 조사연구)

  • 김윤신;김미경
    • Journal of Environmental Health Sciences
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    • v.15 no.2
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    • pp.1-9
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    • 1989
  • A pilot study was conducted in order to measure indoor and outdoor formaldehyde levels during August 3 - 22, 1988 in several underground spaces in Seoul. Formaldehyde concentrations were monitored during 1 week in selected sampling areas (subway station, underground shopping center, underpass, tunnel, underground parking lot) using passive formaldehyde monitors. In order to investigate a relationship between respiratory prevalence and levels of formaldehyde, each subject was asked to answer respiratory questions. The mean formaldehyde concentrations were 60.1 ppb in subway station, 122.2 ppb in underground shopping stores, 72.1 ppb in underpasses, 39.7 ppb in tunnel, and 75.9 ppb in underground parking lots, respectively. The mean indoor formaldehyde concentrations in underground environments varied from 28.6 ppb to 118.7 ppb. Generally, the mean formaldehyde concentrations in ticketing office in subway stations appeared higher than those level measured in platform. The mean formaldehyde concentrations of underground shopping center in Gangnam Terminal were higher than any other areas and it exceeded 100 ppb of the American Ambient Air Quality Standards of formaldehyde. Prevalence rates of respiratory symptoms of dwellers seemed to be related to higher indoor formaldehyde levels.

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Properties of Urea-Formaldehyde Resin Adhesives with Different Formaldehyde to Urea Mole Ratios

  • Park, Byung-Dae
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.5
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    • pp.67-75
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    • 2007
  • As a part of abating the formaldehyde emission of urea-formaldehyde (UF) resin adhesive by lowering formaldehyde to urea (F/U) mole ratio, this study was conducted to investigate properties of UF resin adhesive with different F/U mole ratios. UF resin adhesives were synthesized at different F/U mole ratios of 1.6, 1.4, 1.2, and 1.0. Properties of UF resin adhesives measured were non-volatile solids content, pH level, viscosity, water tolerance, specific gravity, gel time and free formaldehyde content. In addition, a linear relationship between non-volatile solids content and sucrose concentration measured by a refractometer was established for a faster determination of the non-volatile solids content of UF resin. As F/U mole ratio was lowered, non-volatile solids content, pH, specific gravity, water tolerance, and gel time increased while free formaldehyde content and viscosity were decreased. These results suggested that the amount of free formaldehyde strongly affected the reactivity of UF resin. Lowering F/U mole ratio of UF resin as a way of abating formaldehyde emission consequently requires improving its reactivity.

A Study on Free-formaldehyde in the Resin Finished cotton Fabric (III) -Extraction of Free-formaldehyde in the Urea-formaldehyde Resin-finished cotton fabric- (수지가공포의 유리 Formaldehyde에 관한 연구(III) -Urea Formaldehyde 수지가공포중의 유리 Formaldehyde 추출-)

  • Cho Soon Chae;Rhie Jeon Sook;Rhee Jong Mun;Shin Sang Jin
    • Journal of the Korean Society of Clothing and Textiles
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    • v.5 no.1
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    • pp.23-26
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    • 1981
  • In this paper, the extraction mechanism of free formaldehyde in the urea formaldehyde resin finished cotton fabric is discussed. An empirical equation for formaldehyde release has been formulated. $$F=3.7\times10^{-3}\;H\;T^{2.2326}+440$$ in which, F: the amount of free formaldehyde extracted ($\mu$g/g) H: extraction time (min) T: extraction temperature ($^{\circ}C$)

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Characterization of Formaldehyde-degrading Bacteria Isolated from River Sediment (하천 저질에서 분리한 Formaldehyde 분해 미생물의 특징)

  • Kim, Young-Mog;Lee, Eun-Woo;Kim, Su-Jeung;Lee, Myung-Suk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.2
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    • pp.84-88
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    • 2008
  • A bacterium growing on formaldehyde as a sole carbon source was isolated by the dilution method from an enrichment culture containing formaldehyde. The isolated strain, YK-32, was identified as Pseudomonas sp. by morphological, biochemical, and genetic analyses. Pseudomonas sp. YK-32 completely degraded 0.05% formaldehyde within 24 hrs. The isolated strain had a high level of formaldehyde dehydrogenase activity, which is thought to be one of the important factors for formaldehyde degradation, when cells were cultivated in the presence of formaldehyde.

A Study on the Disposable Diapers for Formaldehyde Content and its Recognizability and Consumer's Attitudes toward the Products (일회용 기저귀의 Formaldehyde 함량과 인지도 및 소비실태에 관한 연구)

  • Nam Sang Woo;Lee Sun Young
    • Journal of the Korean Society of Clothing and Textiles
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    • v.11 no.3
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    • pp.101-109
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    • 1987
  • This study was designed to measure the amount of formaldehyde in the disposable diapers of seven different products. It was aimed to investigate the actual situation of the diaper consumption and to relate it to the amount of formaldehyde measured. The degree of recognizability on the harmfulness of formaldehyde was also studied. The amount of formaldehyde was measured by means of the Acetyl Acetone method. The a ual situation of consumption and the recognizability of the formaldehyde were investigated by questionnaire. In the survey, the subjects had their babies aged from 0$\~$3 years and lived in Seoul. The statistical methods used were simple frequency and chi-square. The results obtained from this study were as follows; 1) Among seven (7) different disposable diapers, two were found to have less amount of formaldehyde than the Japanese regulation. 2) From the survey on the actual situation of consumption most respondents ($53.7\%$) experienced the dermatological problem after using the disposable diapers. Actually for the diapers which had a lot of formaldehyde, the respondents experienced the problems more severely. 3) The recognizability of formaldehyde was very low. The recognizability on the harnfulness of formaldehyde was lower, which represented the consumers had least or no knowledge about the formaldehyde release problem.

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Effect of Resorcinol as Free Formaldehyde Scavenger for Fabric Finished with Urea-formaldehyde Precondensate. (Urea-Formaldehyde 수지가공포에 있어 Resorcinol의 유리 Formaldehyde 포착효과)

  • Kang, In-Sook;Kim, Sung-Reon
    • Textile Coloration and Finishing
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    • v.9 no.2
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    • pp.41-49
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    • 1997
  • To control free formaldehyde release from fabric finished with N-methylol compounds, resin finished cotton fabric was treated with resorcinol solution, dried and cured. Factors affecting to control formaldehyde release have been investigated. It was shown that the aftertreatment with resorcinol greatly suppressed the free formaldehyde release. Up to concentration of about 5% of resorcinol, the concentration of resorcinol effected on the control of free and evolved formaldehyde. And at high concentration of resorcinol, however, the concentration became rather insensitive to contol formaldehyde release. Addition of some salt catalysts such as ammonium chloride, zinc nitrate, sodium acetate and ammonium acetate, was effective in decreasing formaldehyde release. Considering the effect on the control of formaldehyde and crease recovery, ammonium acetate was concidered to be the best catalyst. It was observed that the optimum curing temperature for the resorcinol treatment was about 15$0^{\circ}C$, and that the curing time did not affected formaldehyde release over three minutes. Although the treatment of resorcinol had a little adverse effect on crease recovery of resin finished fabric, this effect could be negligible.

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Physicochemical Properties of Non-Formaldehyde Resin Finished Cotton Fabric and their Optimal Treatment Condition (비포름알데하이드계 수지 가공제 처리한 면직물의 물리화학적 특성 변화와 최적 처리 조건에 관한 연구)

  • Kim, Han-Gi;Yoon, Nam-Sik;Huh, Man-Woo;Kim, Ick-Soo
    • Textile Coloration and Finishing
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    • v.24 no.2
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    • pp.121-130
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    • 2012
  • Cotton fabrics were treated with some commercial non-formaldehyde and low-formaldehyde resins, and then their effect on the physicochemical properties were respectively investigated including formaldehyde release, tear strength, shrinkage, and wrinkle recovery. Formaldehyde release less than 10ppm was obtained only by non-formaldehyde resin. Considering other factors, the optimal concentration of non-formaldehyde resin was shown to be 9-11%. In case of low-formaldehyde type, 5-7% resin concentration and curing temperature of $160{\sim}170^{\circ}C$ were recommended for optimal finishing condition. The choice and combination of resins and catalysts were also important factors, and preliminary considerations before treating cotton fabrics with resins used in this study are also important to get much better results.