| 초록 |
In this work, we designed new diamine have ether and sulfone bonds and at the same time introduce trifluoromethyl functional groups. New diamine was reacted with four tetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), 4,4'-oxydiphthalic anhydride (ODPA), cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA), and pyromellitic dianhydride (PMDA) respectively. Optical transmittance and yellowness index were measured by UV/visible spectrophotometer and colorimeter. The novel polyimides synthesized showed excellent solubility in polar aprotic solvents as well as m-cresol and dioxane. All of the PIs show the high thermal properties.: 5% weight loss at a temperature range of 406‒556 °C and glass transition temperature is above 247 °C. The PIs exhibit good optical transparency, such as cut-off wavelength in the region of 310-379 nm and above 90‒95% at 550 nm. In addition, all PIs show low refractive indices and low birefringence. |
