서지주요정보
안티몬 이온을 포함한 벤질퀴녹살리니윰 염 촉매형 에폭시 경화계의 특성에 관한 연구 = Chemo-mechanical analysis of cationic epoxy-cure system by benzylquinoxalinium salts having hexafluoroantimonate counteranions
서명 / 저자 안티몬 이온을 포함한 벤질퀴녹살리니윰 염 촉매형 에폭시 경화계의 특성에 관한 연구 = Chemo-mechanical analysis of cationic epoxy-cure system by benzylquinoxalinium salts having hexafluoroantimonate counteranions / 명인호.
저자명 명인호 ; Myung, In-Ho
발행사항 [대전 : 한국과학기술원, 1999].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8010365

소장위치/청구기호

학술문화관(문화관) 보존서고

DCHE 99030

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

The new benzylquinoxalinium salt having hexafluoroantimonate (N-BQH) was synthesized as a cationic catalyst for epoxy-cure system. The chemo-mechanical properties and volume expansion behavior of DGEBA (diglycidylether of bisphenol A)/ N-BQH system were studied for various concentration of N-BQH. This new DGEBA/ N-BQH cure system having the volume-expansion property was compared with the existed DGEBA/ amine cure system having the volume-shrinkage properties. The cure kinetics, thermal properties and rheological, mechanical, swelling behaviors were investigated by isothermal and dynamic DSC, FT-IR, TGA, TMA, DMA, rheometer, tensile and flexural test measurements. The composition of DGEBA/ N-BQH blend was varied within 99.5:0.5, 99:1, 98:2, 97:3, and 95:5 (mol%). The volume expansion rate for the various catalytic concentrations are in the range of 2.3 to 4.0%. The thermal expansion coefficient obtained by TMA increased with the increase in catalytic concentration of N-BQH until 1.0 mol%, after 2.0 mol% they decreased slightly with increasing of N-BQH concentration. The molecular weights between crosslinking points decreased linearly with the increase in the N-BQH concentration until 2.0 mol%, whereas after 3.0 mol% they increased with N-BQH concentration. The internal stress increased with the increase in N-BQH concentration. The cure reaction involves three consecutive reactions and the overall kinetic parameters for these reactions were obtained by using the isothermal DSC technique. This catalytic epoxy resin system seems to contain very complex kinetic reaction mechanisms. In this system the reaction constant k//1 and K//2 increased with increasing N-BQH concentration and curing temperature. This can be due to the good reactivity of hydroxyl group generated by the elevation of N-BQH concentration and curing temperature. The temperature dependence of the gel time is well fitted by the Arrhenius expression. The crosslinking activation energies for the various catalyst concentrations are between 56 and 57 kJ/mol; these results show that the overall curing mechanisms are nearly the same. The glass transition temperature of the 5.0 mol% sample has a lower value than 3.0 mol% sample. This result means that the excess catalyst is harmful to form fully well-developed three dimensional networks. In the dynamic mechanical analysis(DMA), one T//g were observed in all the samples. Until 2.0 mol% sample, strorage modulus and damping factor shifted to the right hand. After 3.0 mol% they shifted to the left hand. This indicates that there is optimum concentration of N-BQH. Tensile modulus behavior is similar to flexural modulus behavior and tensile strength tendency is also similar to flexural strength tendency in considering of concentration of N-BQH. The sample with 0.5 mol% has a higher value of mechanical property than the other samples. This implies that the structure of the DGEBA/ 0.5 mol% N-BQH system should have an optimally and compacted linear planar structure which has good resistance to the deformation and the crack initiation. The DGEBA/ 0.5 mol%N-BQH system for the observed concentration range has higher values of mechanical property than the DGEBA/ amine systems. The morphology of fracture surfaces was studied by SEM. The tensile fracture occurred similar to the flexural fracture. The morphology of the DGEBA/ N-BQH system showed ductile fracture property, while the morphology of the DGEBA/ amine cure system showed brittle fracture property. This catalytic epoxy cure system with 0.5 mol% concentration has lowest value of swelling degree than the other samples. This may be due to well arranged compact structure of the DGEBA/ N-BQH system like those of the density and mechanical properties of 0.5 mol% sample. The DGEBA/ N-BQH system has lower values of swelling degree than the DGEBA/ amine cure systems. The DGEBF/ amine systems have higher values of mechanical properties than the DGEBA/ amine systems. This may be due to compact structure of the DGEBF/ amine system having relatively short main and side chain length.

서지기타정보

서지기타정보
청구기호 {DCHE 99030
형태사항 xviii, 284 p. : 삽도 ; 26 cm
언어 한국어
일반주기 부록 : A, Wide angle X-ray diffraction 분석 결과. - B, Solid state NMR 분석 결과
저자명의 영문표기 : In-Ho Myung
지도교수의 한글표기 : 정인재
지도교수의 영문표기 : In-Jae Chung
학위논문 학위논문(박사) - 한국과학기술원 : 화학공학과,
서지주기 참고문헌 : p. 263-272
주제 에폭시
촉매형경화
벤질퀴녹살리니윰염
열적특성
기계적물성
Epoxy
Catalytic-cure
Benzylquinoxalinium salt
Thermal property
Mechanical-property
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