Sulfonated poly benzoxazole ether

Figure 5.67 Structure of sulfonated poly(benzoxazole ether ketone)s [107].

J. Li, H. Yu, Synthesis and characterization of sulfonated poly(benzoxazole ether ketone)s by direct copolymerization as novel polymers for proton-exchange membranes, J. Polym. Sci. Part A Polym. Chem. 45 (11) (2007) 2273-2286. 

Sulfonated poly(arylene ether ketone(s)) were synthesized by condensation of 2,2 -bi[2-(4-llurophenyl)benzo-xazole-6-yl]hexalluoropropane with sodium 5,5 -carbon-ylbis(2-lluorobenzosulfonate). Copolymers were soluble in polar aprotic solvents and formed tough, flexible membranes. They were resistant to oxidation and thermally stable up to 290 °C. Their proton conductivity at 80 °C depended on their composition and could be as high as 0.055 S/cm, at RH = 95%. At 120 °C, it is more than double at high benzoxazole content [133]. 

Li, J., Lee, C.H., Park, H.B., Lee, YM. (2006) Novel sulfonated poly(arylene ether ketone) containing benzoxazole membranes for proton exchange membrane fuel cell. Macromolecular Research, 14, 438—442. 

Poly(arylene ether benzoxazole)s were also synthesized from the reaction of bis[(4-hydroxyphenyl)benzoxazole]s and activated aromatic difluoro monomers as shown in Eq. (7) [28,29]. The bis[(4-hydroxyphenyl)benzoxazole]s were readily prepared by condensation of the appropriate bis(o-aminophenol) (e.g. 3,3 -dihydroxy-4,4 -diaminobiphenyl) with phenyl-4-hydroxybenzoate in diphenyl sulfone at 260°C. Under proper conditions, the less expensive 4-hydroxybenzoic acid can be used in place of the phenyl ester to provide high yields of the desired bis[(4-hydroxyphenyl)benzoxazole]s. As presented in Table 9, the hexafluoroisopropylidene (6F) containing polymers were amorphous. These polymers were prepared in DMAc. However, the polymers derived from 6,6 -bis[2-(4-hydroxyphenyl)benzoxazole] were prepared in diphenyl sul-... 

PB PBI PBMA PBO PBT(H) PBTP PC PCHMA PCTFE PDAP PDMS PE PEHD PELD PEMD PEC PEEK PEG PEI PEK PEN PEO PES PET PF PI PIB PMA PMMA PMI PMP POB POM PP PPE PPP PPPE PPQ PPS PPSU PS PSU PTFE PTMT PU PUR Poly(n.butylene) Poly(benzimidazole) Poly(n.butyl methacrylate) Poly(benzoxazole) Poly(benzthiazole) Poly(butylene glycol terephthalate) Polycarbonate Poly(cyclohexyl methacrylate) Poly(chloro-trifluoro ethylene) Poly(diallyl phthalate) Poly(dimethyl siloxane) Polyethylene High density polyethylene Low density polyethylene Medium density polyethylene Chlorinated polyethylene Poly-ether-ether ketone poly(ethylene glycol) Poly-ether-imide Poly-ether ketone Poly(ethylene-2,6-naphthalene dicarboxylate) Poly(ethylene oxide) Poly-ether sulfone Poly(ethylene terephthalate) Phenol formaldehyde resin Polyimide Polyisobutylene Poly(methyl acrylate) Poly(methyl methacrylate) Poly(methacryl imide) Poly(methylpentene) Poly(hydroxy-benzoate) Polyoxymethylene = polyacetal = polyformaldehyde Polypropylene Poly (2,6-dimethyl-l,4-phenylene ether) = Poly(phenylene oxide) Polyp araphenylene Poly(2,6-diphenyl-l,4-phenylene ether) Poly(phenyl quinoxaline) Polyphenylene sulfide, polysulfide Polyphenylene sulfone Polystyrene Polysulfone Poly(tetrafluoroethylene) Poly(tetramethylene terephthalate) Polyurethane Polyurethane rubber... 

---