• 제목/요약/키워드: Cross-linking agent

검색결과 136건 처리시간 0.024초

코폴리에테르에스테르 고무 탄성체의 물성에 미치는 가교제의 효과(II) (Effect of cross-linking agents on the properties of copolyetherester elastomer(II))

  • Jang, Young-Joo;Kim, Hae-Young;Baik, Doo-Hyun
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2002년도 봄 학술발표회 논문집
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    • pp.301-304
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    • 2002
  • In the prior work,$\^$l)/ we introduced several chemical cross-linking agents in order to improve elastic recovery of copolyetheresters, but we are confronted by two difficulties. The first is that cross-linking agents interfere with crystal growth which acts as a physical interlocking. The second is that strain at breaking decreases with the amount of cross-linking agent. It is considered that the chemical interlocking parts couldn't be deformed like crystalline phase. (omitted)

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키토산과 1,2,3,4-Butanetetracarboxylic Acid, Citric Acid로 가공된 면직물의 역학적 특성과 가상 봉제 이미지 (Physical Properties and Virtual Cloth Images of Cotton Fabrics Treated with Chitosan, 1,2,3,4-Butanetetracarboxylic Acid and Citric Acid)

  • 김경선;전동원;김종준
    • 패션비즈니스
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    • 제13권1호
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    • pp.102-114
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    • 2009
  • Chitosan is a polysaccharide with cationic amino groups in its structure and has useful properties as functional materials. Various end-use developments of chitosan are in progress. When the cotton fabric is pretreated with chitosan, the hand property of cotton fabric may be improved expecially for the summer apparel. In this study, as a cross-linking agent to introduce chitosan into cotton, BTCA(butane-1,2,3,4-tetracarboxylic acid) or CA(citric acid) was added in order to prevent detachment of chitosan by the cross-linking. During the cross-linking procedure, via the padding-drying-heat setting, amino groups of chitosan and hydroxyl groups of cotton, carboxyl groups of BTCA/CA are cross-linked by forming anhydrous cyclic rings. Since BTCA has four carboxyl groups, cross-linking by thermal treatment is easy, leading to the trials in wrinkle-recovery treatment of cotton fabrics. However, the high price of the BTCA reagent has been a shortcoming in the actual application for industrial use. Therefore, in this study, we tried the application of CA having three carboxyl groups, which is relatively low priced, as the substituting cross-linking agent. The hand of the treated fabrics were evaluated by measuring physical properties. In addition, based on the physical properties, three-dimensional images were introduced by using 3D CAD systems and results were compared.

아크릴계 점착제와 초박형 웨이퍼소재와의 점착특성 - 아크릴 중합체의 측쇄의 영향 - (Adhesion Characteristics of Acrylic Pressure Sensitive Adhesives on Thin Wafer Materials - Effect of Acrylic Copolymer Side Chain -)

  • 유종민;남영희;이승현;김형일;임동혁;김현중;김경만
    • 접착 및 계면
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    • 제10권3호
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    • pp.134-140
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    • 2009
  • 분자설계를 통하여 측쇄를 변화시킨 아크릴공중합체를 합성하여 아크릴공중합체 점착제와 초박형웨이퍼와의 젖음성 및 점착물성을 조사하였다. 선형 아크릴공중합체를 에폭시계 Tetra-DX 가교제와 반응시켜 3차원 망상구조를 형성하고 가교의 영향을 조사하였다. 계면상호작용보다는 아크릴공중합체의 측쇄변화가 젖음성에 더 큰 영향을 미쳤다. 가교도가 증가할수록 probe tack, peel strength가 감소하는 경향을 나타냈다. 가교에 의해 SAFT 내열성이 증가하였지만 가교제의 함량이 증가하면 오히려 SAFT 내열성이 감소하였다.

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Development of Polymeric Blend Microspheres from Chitosan-Hydroxypropylmethyl Cellulose for Controlled Release of an Anti-Cancer Drug

  • Reddy, Lakshmi C. Narayana;Reddy, Rama Subba P.;Rao, Krishna K.S.V.;Subha, M.C.S.;Rao, Chowdoji K.
    • 대한화학회지
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    • 제57권4호
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    • pp.439-446
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    • 2013
  • Chitosan (CS) and hydroxypropylmethyl cellulose (HPMC) blend microspheres were prepared by water-in-oil emulsion technique and were loaded with an anti-cancer drug 5-fluorouracil (5-FU). CS-HPMC microspheres were characterized by Fourier transform infrared spectroscopy to confirm the cross-linking reaction. Scanning electron microscopy (SEM) was also used to assess the surface morphology of particles prepared. The quantity of release of 5-FU from the microspheres have been studied in terms of blend composition and amount of cross-linking agent. Differential scanning calorimetry and X-ray diffraction techniques indicated a uniform distribution of 5-FU particles in microspheres, whereas SEM suggested the spherical structure of the microspheres with slight rough surface. The in vitro drug release indicated that the particle size and release kinetics depend upon blend composition, amount of cross-linking agent used and amount of 5-FU present in the microspheres.

맥아와 Bacillus subtilis B-4-3의 $\beta$-Glucan 분해 효소측정을 위한 새로운 색소기질 (A New Coloured Substrate for the Determination of $\beta$-Glucan Degrading Enzyme from Malt and Bacillus subtilis K-4-3)

  • 이성택
    • 한국미생물·생명공학회지
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    • 제16권2호
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    • pp.79-84
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    • 1988
  • $\beta$-Glucan 분해효소의 간편하며 예민한 활성도 측정방법으로 $\beta$-glucan에 색소와 cross linking agent를 접합시키는 변형기질 제조시 영향을 미치는 조건을 조사하고 맥아와 세균의 $\beta$-glucan분해효소 측정에 적응시켜 활성도를 측정한 결과는 다음과 같다. 1.0g $\beta$-glucan은 0.1N NaOH용액에서 색소 cibacron blue 3 G-A 1.5g과 cross linking agent인 1,4-butanedioldiglycidyl ether 1.25 $m\ell$을 90분간 끓여서 색소 접합기질로 제조하였을 때 $\beta$-glucanase 활성도 측정에 최적조건이었다. 변형기질은 pH5.3 에서 안정성을 보였으며 Bacillus subtilis K-4-3에서 추출한 효소액에 변형기질을 반응시켰을 때 간편하고 정확한 효소활성 측정이 가능하였다. 또한 색소방법을 DNS방법과 비교한 결과 색소방법이 $\beta$-glucan 분해효소 측정에 적당한 방법이었음이 입증되었다.

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The Effect of Chemical Structure of Main Monomers and Cross-linking Monomers for Acrylic Co-polymers

  • Kang, Eun-Jin;Cheon, Ji-Yeon;Lee, Yoon-Gu;Choi, Jae-Hong
    • Elastomers and Composites
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    • 제57권2호
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    • pp.29-39
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    • 2022
  • In this research, the relationships between the chemical structures of 10 different acrylate monomers with 3 different cross-linking monomers were evaluated. The thermal stabilities of the prepared copolymers were evaluated by their weight-loss percentage through thermogravimetric analysis, and their glass-transition temperatures were analyzed using differential scanning calorimetry. Based on the results, some relationships between the chemical structures of the monomers and their properties were derived and are discussed herein.

Formaldehyde Free Cross-linking Agents Based on Maleic Anhydride Copolymers

  • Yoon, Kee-Jong;Woo, Jong-Hyung;Seo, Young-Sam
    • Fibers and Polymers
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    • 제4권4호
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    • pp.182-187
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    • 2003
  • Low molecular weight copolymers of maleic anhydride and vinyl acetate were prepared to develop formaldehyde free cross-linking agents. Since lower molecular weight is favorable for efficient penetration of the finishing agent into the cotton fibers in the padding process, the concentration of the initiator, chain transfer agent and the monomer ratios were varied to obtain copolymers of low molecular weights. The prepared polymers were characterized by GPC, $^1{H-NMR}$, FTIR, DSC and TGA. Copolymers of molecular weights of 2 000 to 10 000 were obtained and it was found that the most efficient method of controlling the molecular weight was by varying the monomer ratios. Poly(maleic anhydride-co-vinyl acetate) did not dissolve in water, but the maleic anhydride residue hydrolyzed within a few minutes to form poly(maleic acid-co-vinyl acetate) and dissolved in water. However, the maleic acid units undergo dehydration to form anhydride groups on heating above ${160}^{\circ}C$ to some extent even in the absence of catalysts. The possibility of using the copolymers as durable press finishing agent for cotton fabric was investigated. Lower molecular weight poly(maleic anhydride-co-vinyl acetate) copolymers were more efficient in introducing crease resistance, which appears to be due to the more efficient penetration of the cross-linking agent into cotton fabrics. The wrinkle recovery angles of cotton fabrics treated with poly(maleic anhydride-co-vinyl acetate) copolymers were slightly lower than those treated with DMDHEU and were higher when higher curing temperatures or higher concentrations of copolymer were used, and when catalyst, $NaH_2$$PO_2$, was added. The strength retention of the poly(maleic anhydride-co-vinyl acetate) treated cotton fabrics was excellent.

가교도가 조절된 세공충진 이온교환막의 제조 및 전기화학적 응용: Part II. 역 전기투석 (Preparation and Electrochemical Applications of Pore-filled Ion-exchange Membranes with Well-adjusted Cross-linking Degrees: Part II. Reverse Electrodialysis)

  • 송현비;문하늘;김도형;강문성
    • 멤브레인
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    • 제27권5호
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    • pp.441-448
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    • 2017
  • 본 연구에서는 다공성 폴리에틸렌 지지체를 기반으로 세 가지 가교제를 혼합 도입한 세공충진 이온교환막을 제조하고 역 전기투석에서 멤브레인의 특성이 발전성능에 미치는 영향을 고찰하였다. 실험 결과, 분자 크기가 다른 가교제를 혼합함으로써 이온교환막의 가교도 및 자유체적이 효과적으로 조절됨을 확인하였으며 상관 분석을 통해 멤브레인의 전기화학적 특성 및 이를 적용한 역 전기투석의 발전성능에 복합적인 영향을 미침을 알 수 있었다. 특히 세공충진 양이온 교환막은 최적 가교조건에서 상용막 대비 동등 이상의 발전 성능을 나타내었으며 음이온 교환막 또한 상용막에 근접하는 우수한 성능을 나타내었다.

다기능성 함불소고분자/Blocked-HMDI 블렌드계의 가교화 반응에서의 촉매 영향 (Catalyst Effects on Cross-linking of a Multi-Functional Fluoropolymer/Blocked-HMDI Blends)

  • 안원술
    • 한국산학기술학회논문지
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    • 제13권5호
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    • pp.2408-2413
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    • 2012
  • 불소를 함유하는 다기능성 함불소고분자의 가교화 반응을 위하여 페놀로 blocking된 HMDI를 사용하고 반응의 촉진을 위하여 주석계 촉매(stanous catalyst)를 사용하여 DSC 및 TGA를 사용하여 반응에 미치는 촉매의 영향을 살펴보았다. 용매 및 HMDI의 blocking제로 사용된 페놀이 약 $150^{\circ}C$에 이르기까지 해리되면서 휘발하게 되고 $230-250^{\circ}C$ 온도에서 가교 생성반응이 이루어지는 것이 관찰되었다. 촉매의 농도에 따른 반응기구의 변화는 없는 대신 촉매가 도입될 경우 100배 이상 빨라지는 급격한 반응속도의 변화가 관찰되었으며, 이에 따른 활성화 에너지는 비촉매계에 대한 81.8 kJ/mol로부터 1 phr 촉매계의 대하여 61.7 kJ/mol까지 감소하는 것이 관찰되었다.