Preparation and Characterization of Electrospun Polyimide Microfibrous Mats with High Whiteness and High Thermal Stability from Organo-soluble Polyimides Containing Rigid-rod Moieties

• Published in: Fibers and polymers Vol. 19; no. 8; pp. 1706 - 1714
• Main Authors: Guo, Chen-yu, Liu, Jin-gang, Yin, Lu-meng, Huangfu, Meng-ge, Zhang, Yan, Wu, Xiao, Zhang, Xiu-min
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Fiber Society 01.08.2018; Springer Nature B.V; 한국섬유공학회
• Subjects: Aminobenzimidazole; Chemical synthesis; Chemistry; Chemistry and Materials Science; Diamines; Dianhydrides; Dimensional stability; Electrospinning; Glass transition temperature; Mats; Organic chemistry; Polyimide resins; Polymer Sciences; Polymers; Resins; Thermal expansion; Thermal stability; 섬유공학; Thermal properties; Electrospinning; Polyimide; Solubility; Whiteness
• ISSN: 1229-9197; 1875-0052
• DOI: 10.1007/s12221-018-8270-4

A series of flexible and tough polyimide (PI) microfibrous mats (PI-1~PI-4) have been prepared via the one-step electrospinning procedure with the organo-soluble PI resins as the starting materials. For this purpose, four PI resins were first synthesized by the chemical imidization reaction from 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and four aromatic diamines containing rigid-rod moieties in their molecular skeletons, respectively. The PI resins derived from 6FDA and aromatic diamines, including PI-1 from 2-(4-aminophenyl)-5-aminobenzimidazole (APBI), PI-2 from 2-(4-aminophenyl)-5-aminobenzoxazole (APBO), PI-3 from 4,4′-diaminobenzanilide (DABA), and PI-4 from 2-chloro-4,4-diaminobenzanilide (Cl-DABA) exhibited good solubility in polar aprotic solvents, such as N-methyl-2-pyrrolidone (NMP) and N,N -dimethylacetamide (DMAc). Flexible and tough microfibrous mats were successfully prepared by a one-step electrospinning procedure from the PI/DMAc solution (solid content: 15–20 wt%; absolute viscosity: 8000–10000 mPa·s). The derived PI mats exhibited good whiteness according to the CIE Lab measurements with W (whiteness) values as high as 94.31, L (lightness) values higher than 94.00, b * (yellowness) values as low as 2.98 and yellow indices (YI) as low as 4.87. In addition, the prepared PI mats exhibited excellent thermal and dimensional stability with the glass transition temperatures ( T g ) higher than 345 °C and linear coefficients of thermal expansion (CTE) as low as 27.8×10 -6 /K.