• 제목/요약/키워드: crosslinking

검색결과 901건 처리시간 0.029초

페놀계 고분자 LB와의 가교화에 다른 특성 (Electrical for Properties for Crosslinking of Phenolic Polymer LB Films)

  • 김경환;정상범;이준호;박재철;권영수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 D
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    • pp.1677-1679
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    • 1999
  • Crosslinked LB films of p-HP (p-hexadecoxyphenol) were produced to insulation layers of electronic devices. The fabrication and the electrical properties of LB films according to crosslinking have investigated respectively to Brewster angle microscopy (BAM), Scanning Maxwell-stress microscopy (SMM), current-voltage (I-V) properties and frequency-capacitance (C-F) characteristics. According to crosslinking, conductivity of p-HP LB films have improved and relative dielectric constant have reduced.

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BTCA를 이용한 PVA 필름의 가교에 대한 연구 (Crosslinking of PVA Films with BTCA)

  • 윤성종;허용찬;장진호
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2008년도 제38차 학술발표대회
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    • pp.135-137
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    • 2008
  • PVA films with 1,2,3,4-Butanetetracarboxylic acid(BTCA) and sodium hypophosphite monohydrate(SHM) were crosslinked via thermal curing. Different parameters affecting on the crosslinking were investigated including BTCA and SHM concentration, curing temperature and time. The cured films was extracted with boiling water and gel fraction was calculated from weight change of the PVA films. Moisture regain of the gelled films was also measured. While the gel fraction of PVA films increased with increasing curing temperature and time, moisture regain decreased. Water resistance of the crosslinked PVA films improved by the BTCA crosslinking treatment.

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Insulation resistance property of EVA (Ethylene-vinyl acetate) photovoltaic module encapsulants

  • 진가언;정태희;주영철;강기환;장효식
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.424.1-424.1
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    • 2016
  • 태양전지 모듈의 봉지재로 사용되는 EVA(Ethylene-Vinyl acetate)는 외부의 환경으로부터 태양전지를 보호해주는 역할을 한다. 하지만 frame의 실링재나 glass edge 부분의 결함으로 인해 수분이 침투되어 모듈의 내부자재에 영향을 미치게 되며, 모듈의 효율 감소나 수명 단축의 원인이 된다. 이러한 결함을 줄이기 위해서는 EVA의 crosslinking degree, 절연 저항 특성을 향상시키는 것이 중요하다. 이에 본 연구에서는 EVA의 crosslinking degree를 보기 위해 soxhlet extraction method를 이용하여 gel content를 측정하였으며, 라미네이션 과정 중 curing time에 따른 gel content 변화를 확인하였다. 또한 이 실험을 바탕으로 gel content에 따른 절연 저항을 측정하여 EVA의 crosslinking degree에 의한 절연 저항 특성을 확인하였다.

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Variations of the Electrical Treeing and Breakdown Characteristics on LDPE Due to Gamma-ray Irradiation

  • Lee, Chung;Ryu, Boo-Hyung
    • International Journal of Safety
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    • 제8권1호
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    • pp.14-17
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    • 2009
  • The $Co^{60}$ $\gamma$-ray irradiation effects on the electrical and thermal characteristics of low density polyethylene crosslinked by Dicumyl peroxide (DCP) were investigated. We experimented on electrical properties as following; electrical tree inception and growing type for applying AC step voltage, AC breakdown strength, volume resistivity with increasing dosage. Also, chemical analyses were performed TGA, gel fraction. These electrical properties changed depending upon its crosslinking degree and byproducts from crosslinking reactions. Crosslinking reactions were considered causing by $\gamma$-ray irradiation and DCP had contained in low density polyethylene.

가교가능한 유기화합물을 이용한 알루미나의 분산과 성형 (Dispersion and Forming of Alumina Powders via Crosslinkable Organic Molecules)

  • 김봉호;신평우;백운규;정연길;최성철;박철원
    • 한국세라믹학회지
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    • 제32권2호
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    • pp.217-226
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    • 1995
  • Alumina powders were dispersed using crosslinkable organic molecules by electrosteric stabilization and then consolidated by crosslinking of organic molecules. The effect of processing variables such as the physicochemical properties of both solvent media and organic molecules, the proportions of mixed organic media, etc. were studied. FT-IR was used todeduce the mechanism of organic molecules adsorption on the alumina particle surfaces. The adsorption characteristics and the electrokinetic behavior of alumina suspensions were correlated with the stability of particle in alumina suspension using rheological measurements. The green body of alumina consolidated by the chemical crosslinking of the adsorbed organic molecules after the alumina suspension had been stabilized was tough enough for green machining and the sintered alumina fabricated by this proposed process also showed a high bending strength and a homogeneous microstructure.

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키토산처리에 의한 텐셀 직물의 개질기능화(I) - 물성 변화를 중심으로 - (Modification of Tencel Fabric Treated with Chitosan ( I ) - Change of Physical Properties -)

  • 배현숙;육은영
    • 한국염색가공학회지
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    • 제14권1호
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    • pp.18-26
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    • 2002
  • Chitosan has reactive amino and hydroxyl groups which can be used to chemically alter its properties under the mild reaction conditions. Thus the cationization of Tencel with Chitosan is effective to modify the fabric. To investigate the modified properties of Tencel fabric, the tests were performed under the several finishing process with enzyme/glutaraldehyde/softener. The internal structure of Tencel which has the structure of cellulose II wasn't changed by enzyme, chitosan and crosslinking agent treatment and the thermal stability was improved by chitosan and crosslinking agent treatment. Wrinkle recovery angle under the dry condition increased highly until $0.1\textrm{mol}/\ell$ of glutaraldehyde concentration, and then decreased. Tensile strength of modified Tencel fabric decreased with increasing of weight loss, but it was improved more or less by chitosan, crosslinking agent and softener. Moisture regain was improved by enzyme and chitosan treatment. And antibacterial activity showed nearly 100% on Tencel fabric treated with 0.5% chitosan and adsorption of metal ion increased with increasing of chitosan concentration.

비스코스 레이온 직물의 방축가공 (Shrinkproof Finish of Viscose Rayon Fabric)

  • 김성동;이인열;이종렬;김민정
    • 한국염색가공학회지
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    • 제10권6호
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    • pp.20-26
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    • 1998
  • 100% viscose rayon fabric was treated with 1,2,3,4-butanetetracarboxylic acid (BTCA) by pad-dry-cure process in the presence of various catalysts. The dimensional stability, mechanical properties and hand values of fabric treated with BTCA were investigated. The ester-crosslinking reaction was influenced by the concentration of BTCA and type of catalyst. The fabric treated with BTCA was comparable or superior to that treated with conventional crosslinking agents such as dimethyloldihydroxyethyleneurea and 4,5-dihydroxy-1,3-dimethyl-2-imidazolidinone in respect of wrinkle recovery, shrinkproof property, retention of strength, and hand values. But in yellowing of fabric, the fabric treated with BTCA was inferior to that treated with conventional crosslinking agents. The fabric treated with BTCA/sodium formate was inferior to that treated with BTCA/sodium hypophosphite in respect of WRA, but had better strength retention and whiteness.

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Performance of PEG on immobilization of zero valent metallic particles on PVDF membrane for nitrate removal

  • Chan, Yi Shee;Chan, Mieow Kee;Ngien, Su Kong;Chew, Sho Yin;Teng, Yong Kang
    • Membrane and Water Treatment
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    • 제9권1호
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    • pp.1-7
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    • 2018
  • The principal objective of this study is to investigate the effect of Polyethylene Glycol (PEG) crosslinking in Polyvinylidene Fluoride (PVDF) in immobilization of Fe and bimetallic Fe/Cu and Cu/Fe zero valent particles on the membrane and its efficiency on removal of nitrate in wastewater. PVDF/PEG polymer solution of three weight compositions was prepared to manipulate the viscosity of the polymer. PEG crosslinking was indirectly controlled by the viscosity of the polymer solution. In this study, PEG was used as a modifier of PVDF membrane as well as a cross-linker for the immobilization of the zero valent particles. The result demonstrates improvement in immobilization of metallic particles with the increase in crosslinking of PEG. Nitrate removal efficiency increases too.

Effect of Glycols and Catalysts on Cotton Fabrics Treated with Glyoxal

  • Lee, Eui-So;Kim, Seung-Il
    • Fibers and Polymers
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    • 제5권3호
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    • pp.230-233
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    • 2004
  • The optimum conditions for durable press treatment of cotton fabrics using glyoxal as a nonformaldehyde crosslinking agent were investigated. Crosslinking reaction was conducted in the presence of different catalysts such as aluminum sulfate, magnesium chloride, or magnesium chloride-citric acid mixture at various mole ratios of catalyst to glyoxal. Aluminum sulfate was proven the most effective one among those used. Glycol addition into a glyoxal padding bath increased the wrinkle recovery angle(WRA) and whiteness of treated fabrics. The optimum mole ratio of glycol to glyoxal was 1:1. Diethylene glycol addition produced better overall performance to the glyoxal-crosslinked fabric compared to ethylene glycol addition.

Crosslinking Reaction of Phenolic Side Chains in Silk Fibroin by Tyrosinase

  • Kang, Gyung-Don;Lee, Ki-Hoon;Ki, Chang-Seok;Park, Young-Hwan
    • Fibers and Polymers
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    • 제5권3호
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    • pp.234-238
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    • 2004
  • Tyrosinase oxidizes the tyrosyl residues in silk fibroin (SF) with oxygen, resulting in the production of ο-quinone residues. Subsequently, the inter-or intramolecular crosslinks are formed by reaction with amino groups in through nonenzymatic process. The measurement of oxygen consumption proved that the tyrosyl residues in SF were mostly oxidized to quinone residues by tyrosinase. The reaction mechanisms were proposed in this study and the crosslinking reaction of ο-quinone residues and the enzymatic oxidation of tyrosyl residues could be confirmed by the measurements of UV, $^1$H-NMR and GFC.