Poly phase-separated morphology

Because of the aqueous solubiUty of polyelectrolyte precursor polymers, another method of polymer blend formation is possible. The precursor polymer is co-dissolved with a water-soluble matrix polymer, and films of the blend are cast. With heating, the fully conjugated conducting polymer is generated to form the composite film. This technique has been used for poly(arylene vinylenes) with a variety of water-soluble matrix polymers, including polyacrjiamide, poly(ethylene oxide), polyvinylpyrroHdinone, methylceUulose, and hydroxypropylceUulose (139—141). These blends generally exhibit phase-separated morphologies. 

Crosslinked sulfonated poly(imide-siloxane) can be obtained by the radical grafting onto the silylmethyl group of poly(dimethylsiloxane) [59]. Large, well-connected hydrophilic domains have been detected by transmission electron microscopy that are responsible for the high proton conductivity of the membrane. The unique phase separated morphology of the membrane is responsible for the outstanding hydrolytic stability. 

Phase separation of poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) blends in the presence of silica nanoparticles was studied by riieological method by Jianping Gao (2012). Rheology is a frequently used method to determine the phase separation temperature. However, unlike the optical method which can show the phase-separated morphology directly, no visual informatimi can be obtained from rheology (Fig. 10.39). 

For PV application, fluorinated poly(arylene ether sulfone)s containing bulky cardo moiety and -CF3 groups have shown improvement in flux and separation factor owing to the increase in FFV and micro-phase-separated morphology allowing penetration of solvents into the membranes. However, fluorinated PAEs with various architectures need to be further explored for PV application. 

Studies on the amorphous state of 2GT have beoi restricted to Brillouin scattering and DSC studies on changes of the amorphous state afforded by heat treatment below the glass transition temperature. Broad line n.m.r. studies and dynamic mechanical behaviour of some aromatic polyesters have been reported and the data related to the transition behaviour in these systems." The thermal behaviour, mechanical properties, and supramolecular texture in polyOiexa-methylene terephthalate)-poly(oxytetramethylene) block copolymer systems has been compared to that of the homopolymers and related to composition and phase separation morphology."- ... 

The rubbery plateau also represents an indicator of miscibility (Badia et al. 2015). Linear triblock copolymers composed of poly(n-butyl acrylate) and polystyrene (PS-PBA-PS) have phase-separated morphologies exhibiting two rnbbery plateaux (Pakula et al. 2011). The first plateau lies between the Tg of the PBA blocks and the Tg of the PS blocks in this region, the glassy PS microdomains act like physical crosslinks for the flexible PBA blocks. The second rubbery plateau starts after the Tg of PS and continues until the order-disorder transition, where the microdomain strncture transforms into a disordered homogeneous phase (Han et al. 1989). The length and the storage modnlns of the rubbery plateau depend on the molecular... 

They also published their works on novel cardo poly(aryl ether sulfone)-based AEMs containing pendant quaternary ammonium groups on aliphatic side chains by direct polymerization using functionalized monomer (Figure 11.14b). TEM observation revealed that the obtained membranes exhibited a distinct phase-separated morphology comprised interconnect ionic clusters in the size of 1-2 nm. The resulting membranes with lEC of 1.44 mmol/g displayed ionic conductivities varied from 30 to 41 mS/cm at 20°C-60°C. 

---