有機導電高分子，聚3-烷基?吩(poly 3-alkylthiophenes , P3ATs)，由於具有良好的導電度及易溶於一般有機溶劑，因此在近幾年來受到許多注目及研究。加入一個長碳鏈烷基在?吩環的第三個位置上，雖然使得高分子(P3ATs)有好的溶解性。然而，側鏈基的加入卻造成P3ATs的穩定性降低，例如將P3ATs鍍成的薄膜經由FeCl3適度氧化摻雜成為氧化態時，會在大氣下，室溫時即自動還原成中性態而產生去摻雜反應，造成的原因可能是由於側鏈基擺動而使得共軛陰離子遠離高分子主鏈。因此，我們製備了一系列?吩及3-烷基?吩的共聚物，如poly(3-octylthiophene-co-thiophene)(CPOTH)、poly(thiophene-octylthiophene) (PTOT)和poly(thiophene-octylthiophene-thiophene) (PTOTT)希望此類共聚物兼具有聚3-烷基?吩之溶解性及聚?吩的穩定度。實驗結果發現所合成之共聚物可溶於一般的有機溶劑中，如氯仿和四氫?喃等。但在雜亂共聚物CPOTH中之Thiophene(TH)/octylthiophene(OT)比大於0.22時，共聚物即不溶於氯仿或四氫?喃中。TH/OT比不但影響共聚物溶解度，也影響其導電度及穩定性。這些共聚物經過氧化摻雜後，其去摻雜速率會隨著共聚物中TH/OT比愈高而愈慢，其中PTOT的去摻雜速率最慢。共聚物摻雜後的導電度也因TH/OT比愈高而有增加的趨勢。 Conducting polymers, polyalkylthiophenes(P3ATs) are attracting extensive attentions, due to their good electrical properties and processability. Enhanced solubilization can be achieved by grafting long alkyl side chains on a polyaromatic backbone as has been demonstrated in P3ATs. However, side chains also decreased the stability of doped polymer, thin films of FeCl3 doped P3ATs dedoped automatically in ambient atmosphere at room temperature. It was believed that the side chain mobility is the major reason in the dedoping reaction of polyalkylthiophene. Therefore, we prepared a series of copolymers consisting of 3-alkylthiophene and thiophene units, such as Poly(3-octylthiophene-co-thiophene)(CPOTH), Poly(3-octyl-2,2’-bithiophene) (PTOT) and Poly(3’-octyl-2,2’;5’2’’-terthiophene)(PTOTT). These copolymers have fair solubility in common solvents, such as chloroform and tetrahydrofuran although not as good as polyalkylthiophene. The mole ratio of Thiophene (TH)/ Octylthiophene (OT) in the copolymers were determined by the infrared spectroscopic and element analysis. It was found that when the TH/OT ratio of the random copolymer is higher than 0.22, the copolymer losts its solubility. The mole ratio of 3-alkylthiophene/thiophene in the backbone of copolymer affects not only its solubility, but also its stability and conductivity. We found that the dedoping rate of CPOTH decreases as the mole ratio of TH/OT increases, and the electric conductivity increases as the mole ratio of TH/OT increases.
