Sulfonated hyperbranched polymers

A hyperbranched polymer 47 containing Re(bipyridine)(CO)3Cl chromophores (the Re(CO)3Cl+ moiety is denoted as [Re]) linked by bipyridineethylene bridges was deposited with a sulfonated polythiophene to yield a solar energy conversion material. This displayed open-circuit voltages of 1.2 V and photocurrents of 27 iA cm 2 under solar illumination [94]. 

In general, hyperbranched polymers are obtained by the polymerization of an AB2 monomer. Thus, in the first step, the hyperbranched PES must be manufactured. For example, the synthesis of 3,5-difluoro-4 -hydroxydi-phenyl sulfone can be accomplished by the reaction of 3,5-difluorophenyl-magnesium bromide with 4-methoxyphenylsulfonyl chloride, followed by deprotection of the phenol group with HBr in acetic acid." ... 

Yan DY, Gao C (2000) Hyperbranched polymers made from A2 and BB 2 type monomers. 1. Polyaddition of l-(2-aminoethyl)piperazine to divinyl sulfone. Macromolecules 33 7693-... 

Gao C, Tang W, Yan DY, Zhu PF, Tao P (2001) Hyperbranched polymers made from A2, B2 and BB 2 type monomers, 2. Preparation of hyperbranched copoly(sulfone-amine)s by polyaddition of A-ethylethylenediamine and piperazine to divinylsulfone. Polymer 42 3437-3443... 

Abstract This chapter describes the apphcation of hyperbranched polymer-based electrolyte membranes for high temperature fuel cells. Hyperbranched polymers with a sulfonic acid group or a phosphonic acid one as a proton source were synthesized and the proton conductivity, thermal property and fuel cell performance of their polymers and crosslinked membranes were investigated. The concept of the proton conduction coupled with the polymer chain motion was proposed for high temperature fuel cells. 

Key words hyperbranched polymer, sulfonic acid group, phosphonic acid group, proton-conducting polymer, high temperature fuel cells. 

Hyperbranched polymer electrolytes with a sulfonic acid group at the periphery... 

Hyperbranched polymers (HBP) with a sulfonic acid (SA) group (HBP-SA), with an acryloyl (Ac) group (HBP-Ac), and with both sulfonic acid and acryloyl groups (HBP-SA-Ac)... 

Although low-molar-mass aliphatic polyesters and unsaturated polyesters can be synthesized without added catalyst (see Sections 2.4.1.1.1 and 2.4.2.1), the presence of a catalyst is generally required for the preparation of high-molar-mass polyesters. Strong acids are very efficient polyesterification catalysts but also catalyze a number of side reactions at elevated temperature (>160°C), leading to polymers of inferior quality. Acid catalysts are, therefore, not much used. An exception is the bulk synthesis of hyperbranched polyesters reported in Section 2.4.5.1, which is carried out at moderate temperature (140°C) under vacuum in the presence of p-toluene sulfonic acid catalyst. The use of strongly acidic oil-soluble catalysts has also been reported for the low-temperature synthesis of polyester oligomers in water-in-oil emulsions.216... 

The actual formation of hyperbranched material proceeds during the polymerization of 3,5-difluoro-4 -hydroxydiphenyl sulfone in the presence of 3,4,5-trifluorophenylsulfonyl benzene or tris(3,4,5-trifluorophenyl)phos-phine oxide as a core molecule. Cyclic oUgomers formed dining this polymerization contribute to a low-molecular-weight polymer ranging from 3400 to 8400 Dalton. A triazin-based AB2 monomer has also been described. This monomer is shown in Figure 7.8. A hyperbranched aromatic poly(ether sulfone) with sulfonyl chloride terminal groups has been prepared by the polycondensation of 4,4 -(m-phenylenedioxy)-bis-(benz-enesulfonyl chloride). The polymerization was carried out in nitrobenzene at 120°C for 3 h in the presence of a catalytic amount of FeCls. ... 

P. Himmelberg and E. Possum. Development of an efficient route to hyperbranched poly(arylene ether sulfone)s. J. Polym. ScL, Part A Polym. Chem., 43 3178-3187,2005. 

Y. Chang, Y. C. Kwon, K. Paik, and C. Kim. Hyperbranched poly(ether sulfone) with 1,3,5-i-triazine moiety. Korea Polym. J., 8 142-146,2000. 

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