Sulfonation graft copolymer

Poly (ary lene ether sulfone)s and poly(arylene ether ketone) have been employed to prepare block and graft copolymers. Generally, the block copolymers can be prepared by reacting functional-group-terminated oligomers with other functional oligomers and monomers. 

Styrenic-siloxane block and graft copolymers, Tg dependence on architecture and molecular weight, 95,95/ Styrenic-siloxane block copolymers, 86 Substrate catalyst ratio, chloromethylation, 18 Sulfonation, instability of sulfonated PPO, improvement, 6 Surface grafting... 

Strongly anionic, highly water-soluble, graft copolymers of starch can be made by adding 2-propenamide and sodium 2,2-dimethyl-3-imino-4-oxohex-5-ene-1-sulfonate (Na DMIH) to the polymerization reactions. See references 43 and 56 for a discussion of these polymers. 

The catalysis of this reaction by grafted copolymer in comparison with well-known catalysts such as /(-toluene sulfoacid, and cross-linked sulfonated polystyrene was investigated. The yield of mono- and disubstituted products is shown in Table 7.2. The specific catalytic activity of grafted copolymers is 100 times or even higher than the same values for the other catalysts. This also can be related to the much higher level of acidity of perfluoroalkyl sulfoacid. 

Block and graft copolymers are composed of significant sequences of different monomer units, normally in a nonstatistical fashion. For block copolymers, these sequences are assembled in a linear fashion whereas in the case of graft copolymers, blocks are grown from or attached to the backbone of another block as branches. In the case of block and graft copolymer PEMs, these sequences may be composed of significantly different chemical units or units that are chemically identical except that one block is sulfonated and the other is not. 

HorsfaU, J. A. and LoveU, K. V. 2002. Comparison of fuel cell performance of selected fluoropolymer and hydrocarbon based grafted copolymers incorporating acrylic acid and styrene sulfonic acid. Polymers for Advanced Technologies 13 381-390. 

The emulsion polymerization process involves the polymerization of liquid monomers that are dispersed in an aqueous surfactant micelle-containing solution. The monomers are solubilized in the surfactant micelles. A water-soluble initiator catalyst, such as sodium persulfate, is added to the aqueous phase. The free radicals generated cause the dispersed monomers to react to produce polymer molecules within the micellar environment. The surfactant plays an additional role in stabilizing dispersion of the produced polymer particles. Thus, the surfactants used both provide micelles to house the monomers and macroradicals, and also stabilize the produced polymer particles [193,790], Anionic surfactants, such as dodecylbenzene sulfonates, are commonly used to provide electrostatic stabilization [193], These tend to cause production of polymer particles having diameters of about 0.1-0.3 pm, whereas when steric stabilization is provided by, for example, graft copolymers, then diameters of about 0.1-10 pm tend to be produced [790,791]. 

Polymeric carbon nanocomposites are often functionalized with matrix polymers. An example is the functionalization of SWNTs and MWNTs with poly(vinyl alcohol) using a carbodiimide mediated esterification reaction. Also, poly(ethylene-co-vinyl alcohol) is used for this purpose to produce DMSO soluble functionalized SWNTs. In a similar manner poly(m-aminobenzene sulfonic acid) is covalently bonded to SWNTs to form water soluble graft copolymers. ... 

Eisenberg and coworkers have employed acid-base interactions to improve the miscibility of a number of polymer-polymer pairs. Miscible blends were prepared using acid-base interactions, e.g., with SPS (acid derivative) and poly (ethylacrylate-co-4-vinylpyrldine) (91), sulfonated polyisoprene and poly (styrene-co-4-vinylpyridine) (92), and using ion-dipole interactions, e.g., poly (styrene-co-llthium methacrylate) and poly (ethylene oxide) (93). Similarly, Weiss et al. (94) prepared miscible blends of SPS(acid) and amino-terminated poly (alkylene oxide). In addition to miscibility improvements, the interactions between two functionalized polymers offers the possibility for achieving unique molecular architecture with a polymer blend. Sen and Weiss describe the preparation of graft-copolymers by transition metal complexation of two functionalized polymers in another chapter. 

Sulfonation of Graft Copolymer, Styrene graft copolymers (lOg) were sulfonated in concentrated sulfuric acid (90 ml) at various temperatures (60, 70, 80 and 90 C) for 45 minutes. In separate experiments, the graft copolymers (lOg) were sulfonated at 90 for different periods of time (20, 30, 45, 55 and 65 minutes), the mixtures being stirred continuously during reaction. At the conclusion of the sulfonation, the mixtures were cooled to 0-5 C and distilled water added slowly until the concentration was 5M. The sulfonated product was filtered and washed successively with dilute sulfuric acid (2M, 500 ml), water (500 ml), sodium hydroxide (IM, 250 ml), water (500 ml), hydrochloric acid (IM,... 

The product was dried in a vacuum dessicator over silica gel to constant weight. After optimisation of sulfonation conditions, all graft copolymers for ion exchange experiments were sulfonated at 90 for 45 minutes. 

Sulfonic Acid Exchange Resins from Graft Copolymers... 

Table V. Effect of Temperature on Sulfonation of Styrene-Polypropylene Graft Copolymers as Measured by Capacities of...

A latex-supported catalyst has been used to isolate sites. Styrene has been polymerized in the presence of an ionene diblock copolymer (a water-soluble cationic copolymer) to form a graft copolymer latex.31 The cobalt phthalocyanine sulfonate catalyst [CoPc(S03 Na+])4 was added and became attached to the cationic polymer. When this catalyst was used for the oxidation of thiols to disulfides by oxygen, the activity was 15 times that in a polymer-free system. 

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