• Title/Summary/Keyword: anti-oxidation stability

Search Result 35, Processing Time 0.034 seconds

Oxidation Stability of Regenerated Lubricating Oils (Ⅰ). Properties of Regenerated Oils (潤滑再生油의 酸化安定性能 (第1報) 再生油의 性能)

  • Yun Ho Nha
    • Journal of the Korean Chemical Society
    • /
    • v.18 no.6
    • /
    • pp.443-446
    • /
    • 1974
  • The regenerated lubricating oils for an internal combustion engine, obtained from the sulfuric acid and clay treatment, showed an improved thermal oxidation stability regardless of additives, especially anti-oxidant, originally presented in the oils. It is believed that such improvement is due to the formation of anti-oxidant materials, which is observed by the in crease of 25 % of aromatic compounds.

  • PDF

Oxidation Stability of Regenerated Lubricating Oils (II) Formation of anti-Oxidant Materials (潤滑再生油의 酸化安定性能 (第2報). 抗酸化性 物質의 生成)

  • Nah Yun Ho
    • Journal of the Korean Chemical Society
    • /
    • v.19 no.1
    • /
    • pp.50-52
    • /
    • 1975
  • The oxidation stability of samples prepared by blending samples reported previously with diesel oil and diesel oil with additives(alkyl benzene and phenolic type of materials), was tested to study the mechanism of thermal oxidation stability of the regenerated lubricating oils. It was found that the improvement of thermal oxidation stability of such oils was caused by the formation of aromatic compounds, especially phenolic type of organic materials.

  • PDF

Effects of NaCl/H3PO4 Flame Retardant Treatment on Lyocell Fiber for Thermal Stability and Anti-oxidation Properties (NaCl/H3PO4 내염화 처리가 라이오셀 섬유의 열 안정 및 내산화 특성에 미치는 영향)

  • Kim, Eun Ae;Bai, Byong Chol;Jeon, Young-Pyo;Lee, Chul Wee;Lee, Young-Seak;In, Se Jin;Im, Ji Sun
    • Applied Chemistry for Engineering
    • /
    • v.25 no.4
    • /
    • pp.418-424
    • /
    • 2014
  • The improved thermal stability and anti-oxidation properties of Lyocell fiber were studied based on flame retardant treatment by using NaCl/$H_3PO_4$ solution. The optimized conditions of flame retardant treatment were studied on various maxing ratio of NaCl and $H_3PO_4$ and the mechanism was proposed through experimental results of thermal stability anti-oxidation. The IPDT (integral procedural decomposition temperature), LOI (limited oxygen index) and $E_a$ (activation energy) increased 23, 30 and 24% respectively via flame retardant treatment. It is noted that thermal stability and anti-oxidation improved based on char and carbon layer formation by dehydrogenation and dissociation of C-C bond resulting the hindrance of oxygen and heat energy into polymer resin. The optimized conditions for efficient flame retardant property of Lyocell fiber were provided using NaCl/$H_3PO_4$ solution and the mechanism was also studied based on experimental results such as IDT (initial decomposition temperature), IPDT, LOI and $E_a$.

Na3PO4 Flame Retardant Treatment on Lyocell Fiber for Thermal Stability and Anti-oxidation Properties (라이오셀의 열 안정 및 내산화 특성 향상을 위한 Na3PO4 내염화 처리)

  • Kim, Hyeong Gi;Kim, Eun Ae;Lee, Young-Seak;In, Se Jin
    • Fire Science and Engineering
    • /
    • v.29 no.2
    • /
    • pp.25-32
    • /
    • 2015
  • The improved thermal stability and anti-oxidation properties of lyocell fiber were studied based on flame retardant treatment by using $Na_3PO_4$ solution. The optimized conditions of flame retardant treatment were studied on various concentrations of $Na_3PO_4$ and the mechanism was proposed through experimental results of thermal stability and anti-oxidation. The integral procedural decomposition temperature (IPDT), limiting oxygen index (LOI) and activation energy ($E_a$) increased 30, 160% respectively via flame retardant treatment. It is noted that thermal stability and anti-oxidation improved based on char and carbon layer formation by dehydrogenation and dissociation of C-C bond resulting the hindrance of oxygen and heat energy into polymer resin. The optimized conditions for efficient flame retardant property of lyocell fiber were provided using $Na_3PO_4$ solution and the mechanism was also studied based on experimental results such as initial decomposition temperature (IDT), IPDT, LOI and $E_a$.

Anti-oxidation and Anti-atopic Dermatitis Effect of Herbal Wood Vinegar (한방목초액의 항산화 및 항 아토피 효과)

  • Kim, Tagon;Nho, Hwa Jung;Jun, Sang Hui;Kim, Kang Bae;Kim, Donguk
    • Korean Chemical Engineering Research
    • /
    • v.48 no.6
    • /
    • pp.690-694
    • /
    • 2010
  • In this study, herbal wood vinegar including Bambusoideae, Cinnamomi Cortex, Zingiberis Rhizoma was tested to see possibility for cosmetic or skin related medicine. Anti-oxidation effect of herbal wood vinegar was tested by DPPH free radical scavenging activity, and showed 97% inhibition rate at $50{\mu}g/ml$. Anti-bacterial effect was tested by disc diffusion method, and it indicated strong anti-bacterial activity against normal skin flora Staphylococcus aureus. Whitening effect was measured by tyrosinase inhibition assay, and it was lower compared with vitamin C. Stability test was done by MTT assay, and cell toxicity was relatively high. Stability was also checked, and there was not significant change in color, aroma, appearance and pH during storage. Anti-atopic dermatitis test was done by hairless mouse and herbal wood vinegar recovered damaged skin to almost normal condition after 9 days of application. IgE concentration in herbal wood vinegar treated mouse was also reduced 30% compared with control. From the study, herbal wood vinegar showed good anti-oxidation, anti-bacterial and anti-atopic dermatitis effect, and had promising application in cosmetic or skin related medicine.

Superhydrophobic and Hydrophobic Anodic Aluminum Anodic Oxide Layer: A Review (초발수성 및 발수성 알루미늄 양극산화피막의 최신 연구 동향)

  • Lee, Junghoon
    • Journal of Surface Science and Engineering
    • /
    • v.51 no.1
    • /
    • pp.11-20
    • /
    • 2018
  • Hydrophobic and Superhydrophobic surfaces are promising technology for the surface finishing of metallic materials due to its water-repellency. Realization of highly water-repellent surface on aluminum and its alloys provides various functionalities for real application fields. In order to realize the hydrophobic/superhydrophobic surfaces on aluminum and its alloys, various technologies have been demonstrated. Especially, traditional anodic oxidation for aluminum has been widely employed for the morphological texturing of surfaces, which is essential to enhance the hydrophobic efficiency. De-wetting superhydrophobic surface on aluminum provides various exceptional properties, such as anti-corrosion, anti-/de-icing, anti-biofouling, drag reduction, self-cleaning and liquid separation. Nevertheless, the durability and stability of superhydrophobic surfaces still remain challenges for their actual applications in engineering systems and industry. In this review, the theoretical/experimental studies and current technical limitations on the hydrophobic and superhydrophobic surface using anodic oxidation of aluminum have been summarized.

Synthesis and Evaluation of Thermo-stable Organic Solderability Preservatives Based Upon Poly(vinyl pyridine-co-methylmethacrylate) (폴리(비닐피리딘-co-메틸메타아크릴레이트) 기반 열안정성 유기솔더보존제의 합성 및 평가)

  • Bui, Tien Van;Choi, Ho-Suk;Seo, Chung-Hee;Jang, Young-Sic;Heo, Ik-Sang
    • Korean Chemical Engineering Research
    • /
    • v.49 no.2
    • /
    • pp.161-167
    • /
    • 2011
  • Recent popularity in mobile electronics requires higher standard on the mechanical strength of electronic packaging. Thus, the method of soldering between chip and substrate in electronic packaging process is changing from conventional method using intermetallic compound to a new method using organic solderability preservatives (OSP) in order to improve the stability and the reliability of final product. Since current OSPs have several serious problems like thermo-stability during packaging process, however, it is necessary to develop new OSPs having thermo-stability. The main purpose of this study is to develop various thermo-stable OSPs based upon poly(vinyl pyridine-co- methylmethacrylate) and to evaluate their anti-oxidation property protecting Cu pad, thermo-stability and solubility to acid- or alcohol-containing aqueous solution during pos-fluxing. All OSPs showed not only good anti-oxidation property, thermo-stability and solubility but also more advantages like low cost, less odor, and less hygroscopic.

Synthesis and Characteristics of Synthetic Lubricants for the Polyol ester derivatives (폴리올 에스테르 유도체에 대한 합성 윤활유의 제조 및 그의 특성)

  • Lee, Jae-Duk;Jeong, Noh-Hee
    • Journal of the Korean Applied Science and Technology
    • /
    • v.26 no.2
    • /
    • pp.213-223
    • /
    • 2009
  • Conventional additives were added to a newly synthesized base oil to create synthetic lubricants. Commercial polyol ester prepared in this laboratory were obtained as esterification of 1,1,1-trimethylol propane and respectively. This newly synthesized base oil had a variable chemical structure that could achieved the following properties; oxidation or thermal stability, low temperature fluidity, and higher flash points. When compared with commercial mineral lubricants, the synthetic lubricants show superior thermal and oxidation stability, and anti-wear properties.

Cosmetic Effect of Mixed Plant Extracts Including Saururus Chinensis, Morus Bombycis Stem and Morus Papyrifera Stem (삼백초, 뽕나무 줄기, 닥나무 줄기 등을 함유한 복합수목추출물의 화장품소재 특성)

  • Jeong, Hyang Li;Kim, Hyun Woo;Kim, Ji Hye;Kim, Jin Hong;Kim, Donguk
    • Korean Chemical Engineering Research
    • /
    • v.50 no.4
    • /
    • pp.610-613
    • /
    • 2012
  • In this study, plant extracts including 25% Saururus chinensis, 20% Morus bombycis stem and 20% Morus papyrifera stem were tested to use as possible cosmetic agent. As cosmetic effect test, cell toxicity test, elastase inhibition assay, tyrosinase inhibition assay, anti-oxidation assay and temperature stability test were done as cosmetic assays. Plant extract showed low cell toxicity, excellent elastase inhibition and anti-oxidation effect, however, tyrosinase inhibition effect was lower. Skin, lotion and essence formulation was made using plant extracts and temperature stability test was done. Skin and essence indicated good stability, however, lotion showed phase separation and severe viscosity variation, which means lotion formulation change. From the research, plant extracts including Saururus chinensis, Morus bombycis stem and Morus papyrifera stem were suitable for possible cosmetic agent.