Kinetics of thermal degradation of polysulfone/polyimide blended polymeric membranes

Abstract

Flat-sheet asymmetric polysulfone (PSF)/ polyimide (PI) blended membranes were fabricated by a phase-inversion technique. The fabricated membranes were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and field emission scanning electron microscopy analyses. The kinetics of thermal degradation of the membranes were studied from thermogravimetric data following Friedman's kinetic approach. The thermal degradation process of the membranes followed first-order rate kinetics, and the activation energy of the thermal degradation process increased with increasing PI content of the membrane compositions.

Pyrolysis and hydrolysis behaviors during steam pyrolysis of polyimide

“…Interestingly, the E app values were similar while the structures of the monomer units were different [11,31], implying that the obtained E app values mainly indicated imide ring fission in the PI main chain. In addition, it is known that the pyrolysis of PI (i.e., the fission of the imide ring) commonly follows model F 1 (A 1 ) [13,31,32], suggesting that F 1 (A 1 ) was the most suitable one of the best three-fitting models. This suggested that the rate of imide ring fission is proportional to the concentration of the unreacted imide rings.…”

Enhanced gas separation performance of PSF membrane after modification to PSF/PDMS composite membrane in CO2/CH4 separation

“…The weight loss observed at the beginning of TGA cycle indicates the presence of moisture or residual solvent in the membrane. 27,28 The presence of moisture or solvent can affect the separation performance of the membrane. It also indicates that there are weak molecular interactions between polymer chains and solvent used.…”

Modelling in mixed matrix membranes for gas separation

“…These MMMs display some characteristic properties of both ceramic and organic polymers . To produce MMMs containing nanosilica, silica precursors such as tetraethyl orthosilicate (TEOS) is added due to controllable reaction rate and ease of processing . Sol–gel technique is capable of forming silica inorganic frameworks from TEOS under ambient conditions.…”

“…Polysulfone (PSF) is reported to be a suitable option that possesses good thermo‐mechanical strength, acceptable gas performance and low cost. Its high resistance to plasticization up to 30 bars pressure, makes it a appropriate for membrane development . Nevertheless, to achieve improved properties, high performance polyimide (PI) is preferred.…”

“…Several equivalent electrical and thermal conductivity models were used in earlier studies for modelling in the MMMs which are based upon the analogies . In this study, the models based upon Maxwell, Bruggeman, Pal and Lewis‐Nielsen are considered . These models assumed spherical shape of fillers which renders the particle geometry effect as insignificant.…”