On the structure, morphology and transport through limitedly flexible chain sulfonated co-polyimide

New polyimide ionomers derived from 4,4′-diamino-[1,1′-biphenyl]-2,2′-disulfonic acid for fuel cell applications

“…The maximum rate of release of absorbed water is recorded at 101.4°C, and the thermal decomposition of sulfonic groups at 361.9°C, which coincides with the data presented in the literature. 32 That is, regardless of the chemical structure of the copolymers and the number of sulfonic groups, their decomposition (according to the maximum rate of this process) practically coincides. The maximum thermal decomposition rate of the main chain of the copolymer BDSA-SPI-2 (NEt 3 ) -1 is recorded at a high temperature of 590.3°C.…”

“…To study the possible conformational features of the macromolecular chain formed by DBTA and BDSA using the GAMESS software package, we optimized the structures of model dimers consisting of two BDSA units linked by DBTA. 32 Three different conformation of the dimer were studied: cis-1, cis-2 or trans with cis-1 and trans favouring a more linear chain conformation. The structures of the dimers were optimized with a 200 step run using N31 basis.…”

Introduction of a crystalline block as a strategy to increase swelling resistance and dimensional stability of sulfonated copolyimide

“…It was previously reported that films from similar blockcopolyimide of BDSA, ODA, and DBTA (SPI-2) (Figure 7) showed lamellar-like microphase separated morphology. 5 Based on the previous data on the SPI-2-block-copolyimide having a similar structure, it was suggested that SPI-311 would demonstrate a similar tendency to form micro-phase separated morphologies as ODA and BAPB have similar reactivity. However, while leading to the blocks of close polycondensation degree, ODA and BAPB differ significantly in terms of the length of the introduced unit of the block and structural features of the DBTA chain they form.…”

Novel hydroxyl‐containing and thermo‐dehydrocyclizable polycondensation polymers for multifunctional materials: Synthesis, properties, application

“…Although at first glance these areas are not related, they all use the possibilities inherent in chemical structure of amphiphilic polymers. The most evident potential of such polymers is the possibility of formation of films with heterogeneous morphologies, which demonstrate microphase separation 1,5,6 . Due to considerable difference in affinities of various domains in these films to certain solvents, it is possible to use them in preparation of efficient membranes for selective transport of substances in liquid media.…”

“…The important features include ability of a polymer for intramolecular and intermolecular interactions (due to the presence of electron donor and electron acceptor atoms) and free volume of a polymer. The prominent examples of polymers capable of microphase separation are sulfated fluoroolefins 7–11 or polysaccharides, 12 sulfated polyimides intended for various purposes 6 . Another promising approach is the introduction of hydrophilic fragments with active hydroxyl groups into aromatic polyimides containing extended rigid hydrophobic domains, as well as heat treatment of hydroxyl‐containing polyimide materials at high temperatures, which leads to unique structural and chemical changes in the polymer backbone and side groups.…”