Dipropargylgermaniums $[RR'Ge(CH_2C \equiv CH)_2$ ;R,R'=$CH_3$or Ph] were prepared by a Grignard reagent of propargylbromide with dimethyl(or diphenyl) dichloro germanium.
Polymerization was attempted by $WCl_6$ and $MoCl_5$ associated with cocatalyst such as organotin and organoaluminium compounds. A molybdenum catalyst was found to be a particularly effective catalyst for the cyclopolymerization of dipropargylgermaniums and $EtAlCl_2$ was very effective cocatalyst.
Polymerization of diphenyldipropargylgermanium (DPPGe) by various catalysts leads to a dark red solid ($\Overline{Mn}=12000$), soluble in common organic solvents. Thus, film could be obtained by solution casting. Polymerization of dimethyldipropargyl germanium (DMPGe) under the same conditions, however, gives only a partially soluble polymer.
The structure of ploymer was identified by $^1H-NMR$, $^{13}C-NMR$, IR, UV-VIS and Raman spectroscopies. From these spectroscopic results, Poly(dipropargylgermanium)s possess polyene structures having cyclic recurring units in the polymer backbone.
Poly(dipropargylgermanium)s have been investigated in terms of physical properties, thermal, oxidative stability and electrical conductivity. TGA exhibits that Poly(DMPGe) retained 95% of its original weight at 180℃ and Poly(DPPGe) retained 95% of its original weight at 350℃. Poly(DPPGe) was more stable to air oxidation than Poly(DMPGe).
Consequently, cyclopolymers having bulkier substituents have better properties such as solubility, air stability and thermal stability than those having smaller substituents. [PDMPGe < PDPPGe]
The electrical conductivity, σ, rises from the undoped level of $10^{-11} S/cm$ to a maximum value $10^{-4}S/cm$ for $I_2$ doping.
본 논문에서는 폴리다이프로파질 유도체들의 합성과 구조확인 및 그 물리적 특성에 관한연구내용을 다루었다.
DMPGe과 DPPGe은 Grignard반응을 통해 합성하였다.
$WCl_6$나 $MoCl_5$에 의해 중합을 행하였으며 유기틴계화합물과 유기알루미늄계화합물을 조촉매로 사용하였다. 다이프로파질 유도체의 중합에 있어서는 유기알루미늄계 (특히, $EtAlCl_2$)화합물이 좋은 조촉매효과를 보였다.
PDPPGe은 유기용매에 매우 잘 녹았고, PDMPGe은 거의 녹지 않았다. 중합체의 용해성이 치환기의 성질에 의해 영향을 받음을 알았다.
$^1H$-NMR과 $^{13}C$-NMR, IR, UV-VIS, Raman 스펙트럼들로 부터 합성한 중합체가 공액이중결합을 가지며 고리화된 구조를 하고 있는 것으로 추정된다.
열무게분석으로 부터 열안정성을, IR변화로 부터 산화안정성을 알아 보았다. DPPGe이 더 높은 안정성을 보여 주었다.
치환기가 큰 DPPGe이 중합수율이 높고 좋은 용해성과 열 및 산화안정성을 나타내었다.
PDPPGe의 전기전도도는 도핑하지 않았을 때 $10^{-11}$S/cm로 부터 도핑하였을 때 $10^{-4}$S/cm의 값을 나타내었다.
