Effects of thermal treatment on the CO2 sorption of triblockcopolymers derived from polyimide and poly(methylmethacrylate)

ABA-type triblock copolymers were synthesized using 4,4-(hexafluoroisopropylidene) diphthalic anhydride-2,3,5,6-tetramethyl-1,4-phenylenediamine (6FDA-TeMPD) and poly(methyl methacrylate) (PMMA). The films were characterized by determining the effects of different content ratios and thermal decomposition of PMMA block on CO2 sorption properties. TGA results showed that a thermal labile block can be completely decomposed under a previously reported thermal condition. SEM results presented that the asperity was micro-phase separation caused by the PMMA block content rate. Numerous pores with sizes of approximately 10 to 50 nm were detected on Block(28/72) and Block(10/90). The isotherms of all films fitted the dual-mode sorption model, and CO2 sorption decreased with increased PMMA content rate. Infinite-dilution CO2 solubility depended on the Langmuir's site of each polymer because S-H0/S-0 of PI and Block(PI/PMMA) varied from 0.84 to 0.92 CO2 affinity was increased by thermal treatment as indicated by the higher b and S-0 values of thermally treated films than those of nontreated films. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42208.