Ether sulphone, blends

Nandan, B. Kandpal, L.D. and Mathur, G.N., Poly(ether ether ketone)/poly(aryl ether sulphone) blends thermal degradation behaviour, Europ. Polym. J., 39 (l),pp. 193-198 (2003). 

Figure 3.18 shows the proton Tip relaxation for a mixture of a poly (ether sulphone) and a polyimide [20]. This relaxation rate is measured from the CPMAS signal intensity as a function of the spin-lock time after the initial build-up. The relaxation times for the homopolymers are 4.5 and 17 ms for polyimide and the poly(ether sulphone). Figure 3.18 shows that identical relaxation rates are observed for both polymers in the blend, and that the rate is a composition weighted average of the homopolymer relaxation rates. This demonstrates that the polymers are mixed on the length scale of 20 A. 

In the case of alpha-olefins, alcohols and alcohol ethoxylates high levels of decomposition products can also be present, notably high levels of 1,4-dioxane (0.5 - 1.0%) when alcohol ethers are sulphated and the residue remains in its acid form for long periods (hours). Residues from a plant running exclusively on alkylbenzene can be blended with the main production stream at a low level to meet sulphonic acid colour standards. 

Organic components can also be introduced in perfluorinated membranes, to increase the membrane selectivity. Polyvinylidene (PVDF) can effectively suppress the swelling of Nafion due to its high crystallite nature and further improve the selectivity [17]. By simple blending of PVDF with Nafion, the CE of the battery can be improved due to its higher ion selectivity, and the EE increases as well. The use of acid-base membranes such as SPEEK (sulphonated poly(ether ether ketone)), and PSf-ABIm (polysulphone-2-amide-benzimidazole) is another way to improve membrane selectivity via the interactions between sulphonated acid and amide basic groups [18,19]. 

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