• Elastomers and Composites
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• 제34권1호
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• pp.31-44
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• 1999

4종류의 고무(NR, SBR, EPDM, BIMS)에 대해 완전가교 고무층과 부분가교 고무층간 계면 결합의 변화에 따른 계면 접착강도를 $30{\sim}120^{\circ}C$ 조건에서 조사하였고, 전자현미경을 이용하여 접착파단면을 조사하였다. 두 개의 완전가교 고무층간 계면에서는 물리적 결합이 계면 접착강도에 주도적인 역할을 하였고, 완전가교 고무층과 부분가교 고무층간 계면에는 물리적 결합과 화학적 결합이 공존하여 계면 접착강도에 영향을 미쳤다. 접착강도가 응집 인열강도와 유사한 수준으로 높을 때 NR은 "계면 노티인열" 형태를, EPDM은 "cross-hatched" 형태를 보였다.

• 멤브레인
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• 제6권1호
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• pp.37-43
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• 1996

키토산용액을 다공성폴리술폰 한외여과막에 코팅을 하여 투과증발용 키토산 복합막을 제조하였다. 제조한 키토산 복합막을 디알데히드를 이용하여 화학적으로 가교하여 물-에탄올 혼합물의 투과증발 분리 실험을 행하였다. 화학적가교를 위하여 사용한 알데히드는 글리옥살, 테레프탈알데히드, 글루탈알데히드였으며, 이중 글루탈알데히드가 가장 우수한 가교효과를 나타내었다. 글루알데히드로 표면가교한 키토산 복합막에 대해서 조작온도와 가교조건에 따른 투과증발 성능을 관찰하였다. ATR-FTIR을 이용하여 글루탈알데히드로 표면가교한 키토산 못합막의 가교메카니즘의 고찰과 주사각도를 변화시키면서 표면으로부터의 가교정도 및 열처리에 의한 free 알데히드의 반응을 관찰하였다. 글루탈알데히드로 표면가교를 하는 경우 가교제의 사슬이 유동성을 가지고 있어서 가교시간의 증가에 따라서 선택도는 점차로 증가하다가 감소하여 최적치를 나타내고, 투과유량은 감소하였다.

• 방사선산업학회지
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• 제5권2호
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• pp.151-157
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• 2011

Crosslinked SPEEK/PVDF membrane were prepared by EB radiation method with various contents of PVDF. The prepared membranes were subjected to a comparative study of proton exchange membranes for fuel cell appreciations. The crosslinked SPEEK/PVDF membranes were characterized by using DMA, DSC and SAXS. The DMA data indicate that the ionic modulus values and cluster $T_g$ decrease with increasing PVDF content. Thus, it was suggested that the number of clustering in the crosslinked membranes can be reduced with increasing PVDF content. The DSC results were shown that the degree of crystalline of the membrane increased with increasing PVDF content. The morphology of the crosslinkied membranes was shown that with increasing PVDF content, the number of crystalline domain of the SPEEK/PVDF membranes increased but ionic aggregation of the membranes decreased. The water uptake behavior, ionic exchange capacity (IEC) and proton conductivity were decreased with increasing PVDF content. The overall findings suggest that the crosslinked membranes offer the possibility for improving the performance of PEMFC, provided that the membranes have thermal and hydration stability.

• 방사선산업학회지
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• 제6권2호
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• pp.171-176
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• 2012

In this study, a crosslinked poly(styrene-butadiene-styrene) [SBS] block copolymers were prepared by using gamma ray irradiation method. The effects of various radiation doses on the degree of crosslinking, thermo property, and morphology of crosslinked SBS block copolymer were investigated. The degree of crosslinking of crosslinked SBS block copolymers were measured by gel-fraction and FT-IR. It was found that the degree of crosslinking of crosslinked SBS block copolymers increases with increase of the irradiation dose while the TGA result shows that the initial degradation temperature of irradiated SBS block copolymer was shifted to lower temperature with increasing irradiation dose. These results indicate that degradation reaction also occurs when SBS block copolymer is exposed to gamma ray irradiation for crosslinking reaction. The SAXS and FE-SEM results indicate that the phase separation of the styrene block and butadiene block was reduced with increasing irradiation dose.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.316-317
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• 2009

The ion-exchange membrane, Nafion, remains as the benchmark for a majority of research and development in IPMC technology. In this research, we employed a novel ionomer named by sulfonated poly(styrene-ran-ethylene) (SPSE) that is crosslinked by UV irradiation. The sulfonic acid groups were stable during the UV irradiation crosslinking process. Water uptake, ion exchange capacity, and proton conductivity are characterized for both pure SPSE and crosslinked SPSE membrane. The bending responses of SPSE actuators under both direct current (DC) and alternating current (AC) excitations were investigated. The voltage-current behaviors of the actuators under AC excitations are also measured. Results showed the crosslinked SPSE actuators have better electromechanical performance than that of pure SPSE actuator with regard to tip displacement as a novel smart material.

• 한국염색가공학회지
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• 제9권3호
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• pp.27-32
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• 1997

Two poly(4-vinylpyridines) having different degree of crosslinking were prepared by radical copolymerization of 4-vinylpyridine with N, N'-tetramethylenebis-acrylamide as a crosslinker. The abilities of these crosslinked polymers to bind acid dyes (methyl orange, ethyl orange, and propyl orange) were investigated at various temperatures in ethylene glycol as the binding medium. From the equilibrium amounts, the first binding constants and thermodynamic parameters for the bindings were evaluated. The first binding constants and thermodynamic parameters were not varied with these dyes. This result indicates that there is no hydrophobic interaction between the crosslinked polymers and the dyes in ethylene glycol. However, the first binding constants showed bell-shaped curves againtst the binding temperatures. This result could be explained in terms of the crosslinked hole size with temperature variation.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.871-874
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• 2014

Monodispersed carbon nanospheres (CNSs) were fabricated by a novel method and their structural properties were investigated. CNSs were prepared by the pyrolysis of nanospherical polystyrenes (PS). With the coating of $SiO_2$ shell, PS particles were effectively separated during pyrolysis process which resulted to CNSs with an average diameter of 40 nm. Moreover, CNSs could be crosslinked with each other through the bondings between the functional groups on their surfaces. Morphology of the fabricated carbon spheres and their crosslinked form were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and fourier transform infrared spectroscopy (FT-IR).

• 전기학회논문지
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• 제61권6호
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• pp.827-832
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• 2012

The crosslinked polyethylene (XLPE) is the most widely used insulating material for power cable. Due to its thermosetting characteristics, the XLPE can not be recycled, while the needs for the environmental friendly and recyclable insulator is rapidly increasing. In this paper, some important and basic electrical properties of non-crosslinked polyethylene such as conduction current characteristics, water the tree characteristics, AC breakdown test were experimentally investigated. It was shown that some of the tested samples had better performances from the application point of view for replacing current XLPE.

• 대한의용생체공학회:의공학회지
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• 제8권1호
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• pp.13-28
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• 1987

Crosslinked poly(2-hydroxyethylmethacrylate) has been prepared by polymerizing 2-hydroxyethyl methacrylate(HEMA) with crosslinkers such as ehyleng glycol dime- thacrylate(EGDMA), tetraethylene glycol dimethacrylate(TEGDMA), tetraethylene glycol diacrylate(TEGDA), divinyl benzene(DVB), and N, N-methylenebisacry- lamide(MAB) in the presence of initiator $\alpha$ , $\alpha$ -azobisisobutyronitrile at 60。C, The synthesized copolymers were identified by FT-lR spectrophotomether. The swelling properties of the crosslinked copolymers in various solvents such as water, methanol, ethanol, n-propanol, and n-butanol were investigated at different temperatures. The thermal properties of the crosslinked coplymers were also measured by differential scanning calorimetry(DSC) and thermogravimetry(TG)

• 한국막학회:학술대회논문집
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• 한국막학회 1994년도 추계 총회 및 학술발표회
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• pp.32-33
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• 1994

Poly(vinyl alcohol)(PVA) membranes crosslinked with Glutaraldehyde (GA) were prepared for the separation of acetic acid-water mixtures. For the preparation of the crosslinked membranes, dry PVA films were immersed for 2 days at 40$\circ$C in reaction solutions which contain different content of GA solution(25% GA in water), aceton and a catalyst, HCl. IR spectroscopy was employed to characterize the crosslinking reaction between hydroxyl groups in PVA and aldehyde groups in GA. Swelling measurements of the crosslinked membranes were carried out in both water and acetic acid to investigate the crosslinking density and swelling behaviour of the membranes.