Sulfonate thermal properties

Table 11 describes the thermal properties of polyether sulfone based on DCDPS and heteroarylenediol. The TgS range from 230 to 315°C and the decomposition temperature is higher than 450°C. Their thermal stability depends on the bisphenol and activated difluoride used in the polymer synthesis (Tables 10 and 11). 

The sulfonation of polyethylene films to produce negatively charged membranes was described above24. While adequate for many uses, these aliphatic polysulfonates lack long-term stability under adverse conditions. To improve performance, attention was directed in recent years to sulfonation of so-called engineering thermoplastics , a class of film-forming polyaromatics with improved mechanical and thermal properties. 

In the previous section it was suggested that the parent polymer structure considerably influence the physical properties of the derived polysulfonates, imparting to them some of the mechanical and thermal properties of the precursors. This trend is particularly evident in the case of the perfluorinated hydrocarbon polymers. Polymers of this kind, such as e.g., poly(tetrafluoroethylene) (PTFE) are exceptional in their inertness to offensive environment, solvent resistance and high-temperature stability. These considerations led in the sixties to the development of unique sulfonic-acid derivatives of fluorocarbon copolymers by the DuPont Company. While several compositions were disclosed in the patent literature51, the preferred composition, which is the basis for the commercial Nafion ion-exchange membrane, is a copolymer of tetrafluoroethylene with a perfluorinated vinyl ether/sulfonyl fluoride52 ... 

PESs fulfill the mechanical and thermal properties requirements and exhibit an excellent resistance to chemicals. However, a major drawback is the hydrophobicity of the membrane material, which excludes spontaneous wetting with aqueous media. PES can be hydrophilicaUy modified by sulf-onation with sulfuric acid. However, this procedure allows just a random distribution of the sulfonic acid groups in the polymer. 

There exist several reports on s5mtheses of polyarylketones, containing bisphthalasinone and methylene [361, 362], naphthalene [363-367] links containing sulfonic groups [368], carboxyl group in side chain Ref [369], fluorine [370-372] and on the basis of carbon monoxide and sty-rol or -sthylstirol [373], It is shown that methylene and bisphthalasinone links in main chain of polyketones are responsible for its good solubility in m-cresol, chloroform. The links of bisphthalasinone improve thermal property of pol mier. 

Investigation of the thermal properties of the membranes was also evaluated and the obtained data are presented in Table 12.7. The T, X, and were found to decrease with the increase in PSSA content in the membranes. The decrease in both and clearly indicates a dilution effect by the incorporation of amorphous sulfonated PS. This finding is consistent with the variation of the other properties... 

The sulfonated aliphatic-aromatic copolyesters exhibit improved thermal properties, in particular, a desirable balance of high temperature properties and improved compostabUity Sulfonated polyesters can be prepared as follows (60) ... 

Sulfonated aUphatic-aromatic copolyetheresters have advantageous thermal properties. Here, in addition, poly(alkylene ether) glycols, such as poly(ethylene glycol), poly(trimethylene ether glycol), poly(tetramethylene ether)glycol are used (61). 

The introduction of a sulfonate functionality into some polyesters has been foimd to enhance the biodegradation rate of the materials. Shaped articles produced from sulfonated aromatic copolyesters containing hydroxyalkanoic acid residues have improved thermal properties (62). 

Zhou and co-workers [27] used calcium carbonate as a reinforcing agent for sulfonated PEEK. The calcium carbonate particles were surface treated and the effect of this on the mechanical and thermal properties were determined. The modulus and yield stress of the composites increased with CaCOs particles loadings. This increase was attributed to the bonding between the particles and the PEEK matrix. DSC experiments showed that the particle content and surface properties influenced the Tg and the T of the composites. The Tg increased with the content of fillers while Tn, decreased. The treated fillers were found to give a better combination of properties, which indicated that the sulfonated PEEK played a constructive role in the calcium carbonate/PEEK composites. 

May, R. Victrex aromatic polymers for high temperature application. Proc. 7 Annu Des. Ing. Conf., Birmingham, 25-27 Sept, 1984 Kempston, 1984. P. 313-318. Shinyama, K., Fujita, S. Dielectric and thermal properties of irradiated polyetheretherketone IEEE Trans. Dielec, and Elec. Insul.. 2001. 8, N 3, c. 538-542. Hamciuc, Comeliu, Bruma, Maria, Klapper, Marcus Sulfonated poly(ether-ketone)s containing hexafluoroisopropylidene groups J. Macromol. Sci. A. 2001. 38, N 7, P. 659-671. 

Zhou et al. [173] studied the effects of surface treatment of calcium carbonate particles with sulfonated polyether ether ketone on the mechanical and thermal properties of composites with polyether ether ketone in various proportions prepared using a twin-screw extruder. These workers used tensile, impact, and flexural testing, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. The influences of filler particle, loading, and surface treatment on deformation and crystallinity of polyether ether ketone were discussed. 

M, Colonna, C. Berti, E. Binassi, M. Fiorini, S. Karanam and D. J. Brunelle, Nanocomposite of montmorillonite with telechelic sulfonated polyfbutylene terephthalate) effect of ionic groups on clay dispersion, mechanical and thermal properties, Eur. Polym. J., 46 918-927,2010. 

A poly(arylene ether sulfone) (22) containing TPD moieties was synthesized by the reaction of the corresponding bisphenol with 4,4 -difluorodiphenylsulfone [99]. The weight average molecular weight of the polymer (22) was determined to be 9300. Its thermal properties are excellent for the appKcation in electroluminescent devices as hole transport layer. The glass transition temperature of the polymer (22) is 190 °C. 

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