• Title/Summary/Keyword: silane modification

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Modification of Cotton Fibers via In-Situ Polymerization of Silane Monomers (Sliane 중합을 통한 면섬유의 개질에 관한 연구)

  • 오경화
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.3
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    • pp.410-418
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    • 1994
  • 다양한 유기관능기를 가진 Silane가요제의 기능 양면성과 독특한 화학적 구조는 이들이 면섬유의 물성을 향상시키기 위한 in-situ 중합 및 가교처리의 단량체로 사용될 수 있는 가능성을 시사하므로, 본 연구에서는 이를 위한 기초 실험으로 수용액 상의 silane 단량체의 거동과 in-situ중합의 가능성을 조사하였다. 관능기를 달리하는 methyltriethoxysilane (MES), vinyltriethoxysilane (VES), vinyltriacetoxysilane (VAS)과 epoxy (glycidoxy) propyltrimethoxysilane (EMS) 등이 silane단량체로 선택되었다. Silane수용액의 안정성과 용해도는 단량체의 농도가 증가함에 따라 감소하였으며, pH에 의해서도 크게 영향을 받아 PH 3과 4.5사이에서 가장 안정함을 나타내었다. 10분간의 중기 고착과정에 의해서 충분한 양의 단량체가 면섬유 안으로 확산되었으며, 섬유의 방추성은 반응성이 높은 organotin촉매제를 사용하여 열처리한 후 증가되었다.

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Wear Characteristics and Thermal Stability of PA66/silane treated MoS2 Composites

  • Nam, Ki-dong;Gu, Bo-ram;Ryu, Sung-hun
    • Elastomers and Composites
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    • v.55 no.4
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    • pp.339-346
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    • 2020
  • We functionalized a wear-resistant carbon-based MoS2 filler to solve its limited wear condition problem. The filler exhibits excellent lubricative properties. The surface modification of MoS2 was carried out using a (3-glycidyloxypropyl)trimethoxysilane (GPTMS) silane coupling agent to improve the low compatibility and dispersibility of the filler that generally degrade the performance of composites. A silane coupling agent was employed for the functionalization of MoS2, and its effect on the wear resistance of MoS2/Polyamide-6,6 was investigated. The silanization of MoS2 was identified by contact angle analysis and Fourier-transform infrared, energy dispersive X-ray, and X-ray photoelectron spectroscopies. The wear resistance of the composite was found to be improved significantly by the surface functionalization of MoS2.

Mechanical Properties of Styrene-Butadiene Rubber Reinforced with Silica by in situ Tetraethoxysilane Hydrolysis over Acid Catalyst

  • Li, Qingyuan;Li, Xiangxu;Cho, Ur Ryong
    • Elastomers and Composites
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    • v.53 no.2
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    • pp.57-66
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    • 2018
  • Styrene-butadiene rubber (SBR), reinforced with different contents of silica (with or without modification using silane coupling agents), was prepared by a modified sol-gel method involving hydrolyzation of tetraethoxysilane over an acid catalyst. The structures of the as-prepared samples were characterized using various techniques, such as scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The mechanical properties of the as-prepared samples were discussed in detail. The results revealed an increasing of the storage modulus (G') with increase in the silica content without modification. In contrast, G' decreased after modification using silane coupling agents, indicating a reduction in the silica-silica interaction and improved dispersion of silica in the SBR matrix. Both tensile stress and hardness increased with increase in the silica content (with modification) in the SBR matrix, albeit with low values compared to the samples with un-modified silica, except for the case of silica modified using (3-glycidyloxypropyl) trimethoxysilane (GPTS). The latter observation can be attributed to the special structure of GPTS and the effort of oxygen atom lone-pair.

Flexural behavior of carbon nanotube-modified epoxy/basalt composites

  • Kim, Man-Tae;Rhee, Kyong-Yop
    • Carbon letters
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    • v.12 no.3
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    • pp.177-179
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    • 2011
  • The use of carbon nanotubes (CNTs) as a reinforcing material in a polymer matrix has increased in various industries. In this study, the flexural behavior of CNT-modified epoxy/basalt (CNT/epoxy/basalt) composites is investigated. The effects of CNT modification with silane on the flexural properties of CNT/epoxy/basalt composites were also examined. Flexural tests were performed using epoxy/basalt, oxidized CNT/epoxy/basalt, and silanized CNT/epoxy/basalt multi-scale composites. After the flexural tests, the fracture surfaces of the specimens were examined via scanning electron microscopy (SEM) to investigate the fracture mechanisms of the CNT/epoxy/basalt multi-scale composites with respect to the CNT modification process. The flexural properties of the epoxy/basalt composites were improved by the addition of CNTs. The flexural modulus and strength of the silane-treated CNT/epoxy/basalt multi-scale composites increased by approximately 54% and 34%, respectively, compared to those of epoxy/basalt composites. A SEM examination of the fracture surfaces revealed that the improvement in the flexural properties of the silane-treated CNT/epoxy/basalt multi-scale composites could be attributed to the improved dispersion of the CNTs in the epoxy.

Preparation and Physical Properties of Poly(lactic acid) Bio-Composites using Surface Modified Microfibriled Celluloses

  • Yeo, Jun-Seok;Seong, Dong-Wook;Hwang, Seok-Ho
    • Elastomers and Composites
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    • v.50 no.1
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    • pp.62-67
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    • 2015
  • The surface modification of microfibriled cellulose (MFC) was carried out through the hydrolysis-condensation reaction using (3-aminopropyl)triethoxysilane (APS) and 3-glycidyloxypropyltriethoxysilane (GPS) and then the modified cellulose was compounded with bio-degradable poly(lactic acid) (PLA). Also, pristine MFC was compounded with PLA as a control groups. The confirmation of surface modification for the pristine MFC was characterized by FT-IR and SEM/EDX. The thermal and mechanical properties of the PLA/MFC composites depended on the content of MFC and the type of silane coupling agents. From the thermal, morphological and mechanical behaviors of the PLA/MFC composites, it was found that GPS-MFC was more successful to improve the interface adhesion between PLA matrix and the surface of MFC than that of APS-MFC.

Surface Modification of Flake-Shaped Inorganic Mica and Their Cool Paint Performances (판상형 무기소재인 Mica의 표면개질 및 차열페인트의 특성 평가)

  • Park, Jeong Min;Kim, Hee Jung;Yoo, Jung Whan
    • Applied Chemistry for Engineering
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    • v.27 no.1
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    • pp.35-38
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    • 2016
  • In this study, the mica used as a thermal-insulation material was modified with a silane coupling agent, octyltriethoxysilane (OTES), to improve its hydrophobicity. The modified mica was characterized using FT-IR spectrometer, water wettability test, and water contact angle measurement. The analysis exhibits that OTES for the modified mica sample was well bonded chemically and drastically enhanced the hydrophobicity. The reflectance observed as 73.9% (mica) and 86.4% (OTES/mica), respectively, for OTES/mica was improved about 12.5% before any modifications. Also the modified mica sample showed $7.2^{\circ}C$ decrease in the thermal-insulation performance of cool paints compared to that of using unmodified mica, indicating that the modification of mica with silane coupling agents could be effective in enhancing the thermal-insulation performance of the cool paint.

Effect of surface treatment of graphene nanoplatelets for improvement of thermal and electrical properties of epoxy composites

  • Kim, Minjae;Kim, Yeongseon;Baeck, Sung Hyeon;Shim, Sang Eun
    • Carbon letters
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    • v.16 no.1
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    • pp.34-40
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    • 2015
  • In this study, in order to improve the thermal and electrical properties of epoxy/graphene nanoplatelets (GNPs), surface modifications of GNPs are conducted using silane coupling agents. Three silane coupling agents, i.e. 2-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane (ETMOS), 3-glycidoxypropyltriethoxysilane (GPTS), and 3-glycidoxypropyltrimethoxysilane (GPTMS), were used. Among theses, GPTMS exhibits the best modification performance for fabricating GNP-incorporated epoxy composites. The effect of the silanization is evaluated using transmission electron microscopy (TEM), scanning electron microscopy, thermogravimetric analysis, and energy dispersive X-ray spectroscopy. The electrical and thermal conductivities are characterized. The epoxy/silanized GNPs exhibits higher thermal and electrical properties than the epoxy/raw GNPs due to the improved dispersion state of the GNPs in the epoxy matrix. The TEM microphotographs and Turbiscan data demonstrate that the silane molecules grafted onto the GNP surface improve the GNP dispersion in the epoxy.

Effect of Surface Modification of CaCO3 Nanoparticles by a Silane Coupling Agent Propyltrimethoxysilane on the Stability of Emulsion and Foam (실란 커플링제 프로필트리메톡시실란에 의해 표면 개질된 CaCO3 나노입자가 에멀젼과 기포 안정성에 미치는 영향에 관한 연구)

  • Lee, YeJin;Park, KiHo;Lim, JongChoo
    • Applied Chemistry for Engineering
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    • v.31 no.1
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    • pp.49-56
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    • 2020
  • In this study, surface modification of CaCO3 nanoparticles by a silane coupling agent propyltrimethoxysilane (PTMS) was conducted and the effect of surface hydrophobicity on the stability of foam and emulsion was studied in order to test the potential applicability as a foam stabilizer or an emulsifier. The surface modification of CaCO3 nanoparticles by PTMS was confirmed by FT-IR, DSC and TGA analysis. The atomic concentration of CaCO3 particle surface treated by PTMS has been also identified by using XRD and XPS analyses. Both floating tests and contact angle measurements were also performed to examine the effect of PTMS concentration on the surface modification of CaCO3 nanoparticles.

Improvement of Mechanical Interfacial Properties of Epoxy/Clay Nanocomposites Using Silane Intercalant (실란유기화제를 이용한 에폭시/클레이 나노복합재료의 기계적 계면 물성 향상)

  • Park, Soo-Jin;Seo, Dong-Il;Lee, Jae-Rock
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.125-128
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    • 2001
  • In this wort, the $Na^+-MMT$ has organically modified with silane intercalant to prepare the polymer/clay nanocomposites. The pH. X-ray diffraction (XRD), and contact angles were used to analyze the surface properties of clay and the exfoliation phenomenon of clay interlayer, The mechanical interfacial properties of epoxy/clay nanocomposites were investigated by three-point bending test. From the experimental results. the surface modification made by silane intercalant on clay surface leads to an increase of distance of silicate layers, surface acid value. and electron acceptor parameter of organoclay. The treatments are also necessary and useful for epoxy to intercalate into the interlayer by interacting of electron donor-accepter between basic epoxy and clay surface. The mechanical interfacial properties of the nanocomposites was improved by the presence of dispersed clay nanolayer containing low content of organoclay in comparison with the conventional, which increase the interfacial adhesion between dispersed clay and epoxy resins.

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Control of Surface Chemistry and Electrochemical Performance of Carbon-coated Silicon Anode Using Silane-based Self-Assembly for Rechargeable Lithium Batteries

  • Choi, Hyun;Nguyen, Cao Cuong;Song, Seung-Wan
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2519-2526
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    • 2010
  • Silane-based self-assembly was employed for the surface modification of carbon-coated Si electrodes and their surface chemistry and electrochemical performance in battery electrolyte depending on the molecular structure of silanes was studied. IR spectroscopic analyses revealed that siloxane formed from silane-based self-assembly possessed Si-O-Si network on the electrode surface and high surface coverage siloxane induced the formation of a stable solid-electrolyte interphase (SEI) layer that was mainly composed of organic compounds with alkyl and carboxylate metal salt functionalities, and PF-containing inorganic species. Scanning electron microscopy imaging showed that particle cracking were effectively reduced on the carbon-coated Si when having high coverage siloxane and thickened SEI layer, delivering > 1480 mAh/g over 200 cycles with enhanced capacity retention 74% of the maximum discharge capacity, in contrast to a rapid capacity fade with low coverage siloxane.