The enhancement of mechanical properties of P84 hollow fiber membranes by thermally annealing below and above Tg

Publication date: Available online 20 October 2019Source: Journal of Membrane ScienceAuthor(s): Lujie Sheng, Jizhong Ren, Kaisheng Hua, Hui Li, Yuxuan Feng, Maicun DengAbstractIn this paper, BTDA-TDI/MDI (P84) co-polyimide hollow fiber membranes (HFMs) were prepared by dry-jet wet spinning technique. The P84 HFMs were thermally annealed below and above P84 Tg (321.5 °C) to investigate their mechanical properties and gas separation properties. Thermally annealing at different temperature below and above Tg influenced the tensile strength, Young's modulus and the elongation at break significantly. Compared with the pristine P84 HFMs, the tensile strength and Young's modulus of the thermally annealed P84 HFMs decreased slightly when the thermally annealing temperature was 180, 200 and 250 °C. However, the tensile strength of the thermally annealed P84 HFMs began to increase when the thermally annealing temperature approached to its Tg (such as 300 °C), which was induced by the increased molecular weight (Mw) and CTCs (charge transfer complexes) formation. Compared with the thermally annealed P84 HFMs below Tg, the HFMs' tensile strength, Young's modulus and the elongation at break increased greatly with thermally annealing above Tg, which was due to the obvious cross-linking reaction of P84. To further understand the effect of thermally annealing below and above Tg, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) with attenuated total reflection ...
Source: Journal of Membrane Science - Category: Materials Science Source Type: research