Diimide-Diacid Architecture Effect on the Synthesis of Rigid-rod Polybenzobisthiazoles

• Main Authors: Yu-Chang Yu, 余玉章
• Other Authors: Li-Fang Wang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/93304175670882019819

碩士 === 高雄醫學大學 === 藥學研究所碩士在職專班 === 93 === Three diimide diacids，including 4,4''-thiodiphenyldiimide diacid (DIDA-S)，4,4''-oxydiphenyldiimide diacid (DIDA-O)，and 4,4''-methylenediphenyldiimide diacid (DIDA-CH2)，have been synthesized with high yields in this study。 A direct polycondensation between 2,5-diamino-1,4-benzenethio- dihydrochloride (DABDT) and the synthesized diimide diacid using polyphosphoric acid as a solvent was then carried out to obtain the conjugated rigid-rod poly(benzobisthiazoles) (PBT). The PBT precursor with pendant diimide diacid groups has an inherent viscosity in the range of 1.23-1.85 dL/g。 Among the three PBTs，PBT-O shows the highest inherent viscosity and best thermal stability，this can be attributed to the higher electronegativity of the oxygen atom in PBT-O. The conductivity measurements indicate little difference between the three PBTs. However，PBT-S is a little bit higher. This may be due to an electron-containing S group and a better molecular packing and alignment to promote the electronic conductivity. On the other hand, PBT-CH2 with a larger d-spacing exhibits looser molecular packing due to the aliphatic chains. All the PBTs can dissolve in the strong solvent like MSA、 TFAA、 MSA/CH2Cl2 (80%/20%)， but are only slight soluble in the weaker solvent like DMSO and NMP.