30. Synthesis and Properties of Cross-Linkable High Molecular Weight Fluorinated Copolyimides
作者：Hongyan Yao, Yunhe Zhang, Yu Liu, Kaiyuan You, Shanyou Liu, Baijun Liu, Shaowei Guan
關鍵字：fluorinated copolyimide,crosslinking
論文來源：期刊
具體來源：Journal of Polymer Science Part A: Polymer Chemistry, 2014, 52(3): 349-359.
發表時間：2014年
A series of novel high molecular weight fluorinated co-polyimides (Co-PIs) containing styryl side chain based on 1,3-bis(2-trifluoromethyl-4-aminophenoxy)-5-(2,3,4,5-tetrafluorophenoxy)benzene (6FTFPB) were successfully synthesized. The weight-average molecular weights (M(w)s) and polydispersities of the co-polyimides were in the range 8.93-10.81 x 10(4) and 1.33-1.82, respectively. The co-polyimide film showed excellent solubility in organic solvents, high tensile properties (tensile strength exceeded 91 MPa), excellent optical transparency (cutoff wavelength at 332-339 nm and light transparencies above 89% at a wavelength of 550 nm), and high thermal stability (5% thermal weight-loss temperature up to 510 degrees C). The casting and spinning films could be cross-linked by thermal curing. The cured films show better combination property (including excellent resistance to solvents) than that of co-polyimides. For instance, the glass transition temperature of Co-PI-1 (the molar weight ratio of 6FTFPB was 30%) increased from 217 to 271 degrees C, the tensile strength enhanced from 94 to 96 MPa, the 5% thermal weight-loss temperature improved from 514 to 525 degrees C. Moreover, after cured, Co-PI-1 film also has a coefficient of thermal expansion (CTE) value of 60.3 ppm degrees C-1, low root mean square surface roughness (R-q) at 4.130 nm and low dielectric constant of 2.60.