화학공학소재연구정보센터
Polymer(Korea), Vol.17, No.5, 561-568, September, 1993
Iodine-Doping에 의한 비공액계 고분자의 전도거동에 대한 치환체와 Blends의 효과
The Effect of Substituents and Blends on the Conduction Behavior of Iodine-Doped Polydienes
초록
Iodine-doping에 의한 diene계 고분자의 전도 발현에 있어 고된자의 치환체가 전도도에 미치는 영향을 고찰하여 보았다. 전자 공여성 치환체인 methyl-group을 갖는 polyisoprene(PI)과 polydimethylbutadiene(PDMBD)의 경우 iodine-doping에 의해 10-2∼10-3S/cm 정도의 전도도를 나타내었다. 또한 치환체가 없는 potybutadiene(PBD)는 약 10-7S/cm의 값을 나타내었으며, 전자 흡인성 치환체인 chloro-group을 갖는 polychloroprene(PC)은 전도도가 발현되지 않았다.. 이리한 결과는 methyl 치환체가 이중결합의 전자밀도를 높여줌으로서 고분자와 iodine 간의 착체의 형성을 용이하게 때문으로 생각된다. 고분자와 iodine간의 착체의 형성 반응에 있어 착체의 혈성효율을 알아 보고자 Benesi-Hildebrand plot을 이용하여 평형상수 값을 계산한 걸과 PI, PBD. PDMBD 및 PI/PBD copolymer가 각각 40, 31, 44.8. 37.5의 값을 나타내었다. 또한 PC/PDMBD 및 PC/PBD blends를 제조하여 각 혼합물에 있어 함량에 따른 전도도의 변화를 관찰하여. 낮은 농도의 PDMBD 및 PBD 함량에서는 전도도가 임계 percolation 농도에 의존한다는 것을 알 수 있었다.
The effect of substituents on the conductivity of the Iodine-doped polydienes such as polyisoprene(Pl), polybutadiene(PBD), polydimethylbutadiene(PDMBD) and polychloroprene(PC) was studied. PI and PDMBD having electron-releasing silbstituent(methyl-group) turned black upon doping and conductivities were in the range of 10-2 10-3/cm. The conductivity of PBD having no substituent was about 10-7S/cm and, in the case of PC having electron-withdrawing substituent(chloro-group), remained as low as it was before treatment(∼10-12S/cm). These results showed that the inductive effect of the methyl substituent on the double bond enhances the electron-releasing tendency so that the complex between polymer and iodine was formed with ease. In the reaction of complex formation, the equilibrium constant was calculated, using the Benesi-Hildebrand plots. The equilibrium constant of PI, PBD, PDMBD and PI/PBD copolymer were 40, 31, 44.8 and 37.5, respectively PC/PDMBD, PC/PBD and PI/PB blends were prepared and the conductivity was measured as a function of the component. The conductivity of blends depended on the critical percolation concentration at the low concentration of a conductive component.
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