• Title, Summary, Keyword: Crosslinking

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Water Tree Characteristics of XLPE/EnBA Blends as a function of Crosslinking Coagent Contents (XLPE/EnBA에서의 가교조제에 따른 수트리 특성)

  • 오우정;서광석;김종은
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.219-222
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    • 1998
  • In this study, The water tree characteristics were investigated when crosslinking coagent was added in XLPE/EnBA blends. When XLPE was blended with EnBA, there was a decrease of water tree length as an increase of nBA contents in XLPE/EnBA20 blends. The effect of crosslinking coagent. A was better than those of other crosslinking coagents B, C and D in water tree retardation. In case of XLPE/EnBA/Crosslinking coagent blends, water tree length was increased as the crosslinking coagents were increased from 0.2 to 2 phr in 2.0 phr DCP content. To clarify the effects of crosslinking coagent, the DCP contents were changed from 1.5 to 2.0 par in the same crosslinking coagent contents. Then, there was a decrease of water tree length as an increase of crosslinking coagent contents in 1.5 and 1.8 phr DCP contents.

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Study on the Crosslinking Characteristics of LDPE and LLDPE by $\gamma$-Ray Irradiation ($\gamma$-선 조사에 의한 LDPE, LLDPE의 가교특성에 관한 연구)

  • 김정일;박성현;강필현;노영창
    • Polymer Korea
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    • v.25 no.5
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    • pp.657-664
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    • 2001
  • In this study. the effects of ${\gamma}$-irradiation on the crosslinking of low density poly ethylene (LLDPE) and linear low density polyethylene (LLDPE) containing crosslinking agents were investigated to find the degree of crosslinking in the polymer. The LDPE and LLDPE specimens were prepared by blending crosslinking agents with each polymers, and by hot-press-molding into a sheet at 13$0^{\circ}C$. The ${\gamma}$-irradiation was conducted at 50 to 150 kGy in nitrogen. The crosslinking percentage in these specimens was measured in relation to the irradiation dose and the type of crosslinking agents. The mechanical properties, thermal properties and crystallinity of specimens were examined as a function of irradiation dose as well. It was found that the degree of crosslinking of the irradiated specimens was increased with increasing irradiation dose and by the addition of crosslinking agents. The mechanical properties and thermal properties of specimens were improved in proportion to an increase in the degree of crosslinking. The crystallinity of original resin was decreased with increasing crosslinking density.

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Electron Beam-induced Crosslinking and Characterization of Polycaprolactone Films in the Presence of Various Crosslinking Agents

  • Kang, Dong-Woo;Jung, Chan-Hee;Hwang, In-Tae;Choi, Jae-Hak;Nho, Young-Chang
    • Journal of Radiation Industry
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    • v.5 no.2
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    • pp.107-112
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    • 2011
  • Electron beam-induced crosslinking of polycaprolactone (PCL) films containing various crosslinking agents (CAs) was investigated in this study. PCL films containing various CAs prepared by a solution casting method were irradiated by electron beams at various absorption doses and the irradiated PCL films were investigated in terms of their crosslinking degree, thermal and mechanical properties, and biodegradability. Based on the results of the crosslinking degree measurement, triallyl isocyanurate was found to be most effective for the electron-beam induced crosslinking of PCL films. The results of the UTM, DMA, and TMA revealed that the thermal and mechanical properties of the crosslinked PCL films were greatly improved in comparison to those of the pure PCL. The results of the enzymatic degradation test revealed that the biodegradability of the crosslinked PCL films was reduced in comparison to that of the pure PCL.

Crosslinking Characteristics of Ethylene Vinyl Acetate Copolymer by the Structure of Crosslinking Agents (가교제의 화학 구조에 따른 에틸렌 비닐 아세테이트 공중합체의 가교 특성 고찰)

  • Lee, Jong-Rok;Choi, Chang-Suk;Kang, Ho-Jong
    • Polymer Korea
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    • v.33 no.2
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    • pp.131-136
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    • 2009
  • The effect of the chemical structure of the peroxide crosslinking agent on the reactive crosslinking reaction of EVA was investigated and the physical properties of the crosslinked EVA were studied as well. It was found that peroxide with one peroxy group (perbutyl peroxide) is more effective than peroxides with two peroxy group (2,5 dimethyl 2,5 di(tert-butylperoxyl) hexane and 1,1-di(tert-buthylperoxy)-3,3,5-tri-methylcyclohexane) in melt reactive crosslinking reaction of EVA. The rate of crosslinking was increased by the use of crosslinking acceleration agent but the noticeable effect on degree of crosslinking was not found. Crosslinking caused the lowering of melt flow ability of EVA but mechanical properties were enhanced by the crosslinking of EVA.

Hydrolysis of the Ester Crosslinking on Cotton Fabric Treated with Polycarboxylic Acid(I) (polycarboxylic acid 처리면포의 Ester 가교결합의 가수분해 (I))

  • 강인숙;배현숙
    • Textile Coloration and Finishing
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    • v.15 no.4
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    • pp.24-31
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    • 2003
  • In this research, we applied FT-IR spectroscopy to study the hydrolysis of the ester-crosslinking formed by various polycarboxylic acids on the cotton fabric. We observed the following; (1) the ester-crosslinking is less durable to hydrolysis than ether-crosslinking under all conditions; (2) the ester-crosslinking formed by polycarboxylic acids having more than three carboxyl groups, such as butanetetracarboxylic acid (BTCA), are substantially more durable to hydrolysis than the acids having two or three carboxyl groups, such as maleic and citric acid; (3) alkaline conditions drastically accelerate the hydrolysis of both urea- and ester-crosslinking; and (4) the ester-crosslinking formed by poly(maleic acid) is more resistant to hydrolysis at alkaline conditions than BTCA. (5) polycarboxylic acid molecules were removed from the fabric at same rate as the hydrolysis of the ester linkage. FT-IR spectroscopy has proved to be a useful analytical technique for evaluating the hydrolysis of the crosslinked cotton fabric.

Effect of Crosslinking Agents on the Morphology of Polymer Particles Produced by One-Step Seeded Polymerization

  • Kim, Dong-Hee;Lee, Do-Yang;Lee, Kang-Seok;Choe, Soon-Ja
    • Macromolecular research
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    • v.17 no.4
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    • pp.250-258
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    • 2009
  • One-step seeded polymerization was used to prepare $7{\sim}10{\mu}m$ of crosslinked monodisperse spheres with four crosslinking agents using $4.68{\mu}m$ poly(methyl methacrylate)(PMMA) seed particles in aqueous-alcoholic media in the absence of the swelling process. The crosslinking agents used were ethylene glycol dimethacrylate(EGDMA), allyl methacrylate(AMA), 1,6-hexanediol diacrylate(HDDA) and trimethylolpropane trimethacrylate(TMPTMA). The effects of the type and concentration of the crosslinking agents on the swelling, pore size, thermal property of the networks and morphology of the particles were studied. The chemical structures and concentrations of the crosslinking agents affected both the swelling ratio and the porosity of the networks. In addition, the chemistry of the reactive vinyl group and chain length of the crosslinking agents affected the stability of the monodisperse particles of the ultimate morphology.

Tensile strength and Elongation Characteristics for Insulation Crosslinking of XLPE Insulated Power cable (XLPE 절연 전력케이블의 절연체 가교도에 따른 인장강도 및 신장특성)

  • Kim, We-Young;Yun, Dae-Hyuk;Park, Tae-Gone
    • Proceedings of the KIEE Conference
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    • pp.1425-1427
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    • 2002
  • Degree of crosslinking of insulation is very important factor that is determined characteristics of XLPE insulated power cable. Increase of degree of crosslinking is closely related to increase of mechanical characteristics of XLPE insulated power cable. In this study, mechanical characteristics of XLPE insulation for degree of crosslinking was analyzed tensile strength and elongation of insulation. As the result, mechanical characteristics of insulation for degree of crosslinking was divided three cases.

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Synthesis of Crosslinked Chitosan Phosphate and Its Metal Ion Adsorption Characteristics (I)-Crosslinking and Phosphorylation of Chitosan- (인산화 가교 키토산의 합성 및 금속이온 흡착 특성(I)-키토산의 가교 및 인산화 반응-)

  • 이종순;홍성일전동원
    • Textile Science and Engineering
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    • v.31 no.12
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    • pp.966-975
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    • 1994
  • Chitosan. a natural biodegradable polymer, was crosslinked with epichlorohydrin in alkaline condition and phosphorylated with P2O5 in methanesulfonic acid to use as a chelating polymer. Insolubility of crosslinking reaction product in acidic solution confirmed that crosslinking was occurred favorably by epichlorohydrin and it was proved that a swelling ratio of crosslinked chitosan(c-chitosan) in acetic acid solution could be thought as a measure of degree of crosslinking. Crofslinking mechanism was presumed from the various crosslinking methods. The effects of crosslinking ratio and phosphorylation conditions(amount of phosphorus-pentoxide, temperature and time) on the phosphorylation of c-chitosan were investigated.

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Polymeric Reactions of Chloromethylpolystyrene(V)-Effect of Crosslinking Agent. Degree of Crosslinking on the Autocrosslinking of Chloromethylpolystyrene - (클로로메틸폴리스티렌의 고분자 반응에 관한 연구(V)-가교제의 종류와 가교도가 클로로메틸폴리스티렌의 자동가교에 미치는 영향-)

  • 전동원
    • Textile Science and Engineering
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    • v.31 no.10
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    • pp.769-779
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    • 1994
  • Autocrosslinking reaction accompanied in polymeric reactions was investigated quantitatively. The degree of autocrosslinking was measured in chloromethylation of EGD crossliilked polystyreile. The finding from this study is that, in case of crosslinked polystyrene, the rate of autocrosslinking reaction of gel-type polystyrene is faster than that of macroporous-type. And the autocrosslinking reaction is terminaled in an hour from the initial reaction. In induced autocrosslinking of chloromethylpolystyrene obtained from polymerization of chloromethylstyrene monomer, initial autocrosslinking stage governs the whole crosslinking reaction so predominantly that the DVB and EGD crosslinking do not marc much difference. It is proved that the accompanying crosslinking reaction, introduced by the autocrosslinking. has a more significant elect on the polymeric reaction than the crosslinking agent used in chloromethylpolystyrene polymerization.

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Effect of Crosslinking Agent on the Properties of Shape Memory Foam for Footwear (가교제가 운동화 인솔용 발포체의 특성에 미치는 영향)

  • Lim, Sungwook;Park, Eunyoung;Park, Chacheol
    • Textile Science and Engineering
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    • v.49 no.6
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    • pp.411-417
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    • 2012
  • To develop shape memory foam for the insole of footwear, two types of hydrogenated styrene-butadiene random copolymer(HSBR) and ethylene vinyl acetate(EVA) foams were produced, and the effects of content of crosslinking agent on both physical and shape memory properties have been studied. Expansion ratio and permanent deformation of the foams decreased with increasing content of crosslinking agent. The result showed that tear strength and resilience of the foams are independent of the amount of crosslinking agent, but rely heavily on the type of resin within the experimental range. Increasing sulfur ratio of the crosslinking agent increased the shape recovery ratio of the foam, but decreased the shape retention characteristics under compression.