Sulfonyl polymers

The sulfonylated and acylated PPO presents solubility characteristics which are completely different from those of the parent PPO. Table V presents the solubility of some modified structures compared to those of unmodified PPO. It is very important to note that, after sulfonylation, most of the polymers become soluble in dipolar aprotic solvents like dimethyl sulfoxide (DMSO), N,N— dimethylformamide (DMF) and N,N-dimethylacetamide (DMAC). At the same time it is interesting to mention that, while PPO crystallizes from methylene chloride solution, all the sulfonylated polymers do not crystallize and form indefinitely stable solutions in methylene chloride. Only some of the acetylated polymers become soluble in DMF and DMAC, and none are soluble in DMSO. The polymers acetylated with aliphatic acid chlorides such as propionyl chloride are also soluble in acetone. 

Chlorosulfonic acid is employed in the manufacture of synthetic detergents such as sulfates of alkenes or unsaturated oils, polyoxypropylene glycol, long chain alcohols, alkylarenes or alkyl diphenyl ethers. It is also extensively used in the manufacture of sulfonamide antibacterials (sulfa dmgs), diuretics and other pharmaceuticals, pesticides, artificial sweeteners (saccharin), disinfectants (chloramine and dichloramine T), plasticizers, dyes and pigments, sulfonyl polymers as plastics, and ion exchange resins. Chlorosulfonic acid is an oxidizing and... 

PoIysuIfonyIa.tlon, The polysulfonylation route to aromatic sulfone polymers was developed independendy by Minnesota Mining and Manufacturing (3M) and by Imperial Chemical Industries (ICI) at about the same time (81). In the polymerisation step, sulfone links are formed by reaction of an aromatic sulfonyl chloride with a second aromatic ring. The reaction is similar to the Friedel-Crafts acylation reaction. The key to development of sulfonylation as a polymerisation process was the discovery that, unlike the acylation reaction which requires equimolar amounts of aluminum chloride or other strong Lewis acids, sulfonylation can be accompHshed with only catalytic amounts of certain haUdes, eg, FeCl, SbCl, and InCl. The reaction is a typical electrophilic substitution by an arylsulfonium cation (eq. 13). 

The single-monomer route (eq. 5) is preferred as it proves to give more linear and para-linked repeat unit stmctures than the two-monomer route. Other sulfone-based polymers can be similarly produced from sulfonyl haUdes with aromatic hydrocarbons. The key step in these polymerisations is the formation of the carbon—sulfur bond. High polymers are achievable via this synthesis route although the resulting polymers are not always completely linear. 

The distribution of chlorine atoms along the polymer chain has been studied in great detail. The distribution in various functional types is shown in Table 4 (18). High density polyethylene chlorosulfonated to 35% G1 and 1% S has been found to contain only 1.7% highly active chlorines, ie, reactive to weak bases. AH of these are attributed to the chlorine in the sulfonyl chloride group and those in beta position to SO2GI. No vicinal chlorides groups were found (19). 

Chlorination of thiiranes in hydroxylic solvents gives /3-chloroethylsulfonyl chlorides due to further oxidation of the intermediate sulfenyl chloride by chlorine or hypochlorous acid (Scheme 40). Polymer is usually obtained also unless the reaction is done in concentrated hydrochloric acid, which causes rapid ring cleavage to 2-chloroethylthiols which are subsequently oxidized to the sulfonyl chlorides. An 85% yield of (37) is obtained in concentrated hydrochloric acid-HCl(g) whereas only a 15% yield is obtained in CCI4-H2O. 

Styryl sulfonyl chloride Friedel-Crafts cyclization benzo[h]thiophenes from, 4, 873 Succinic anhydrides polymers, I, 277 mass spectrometry, 4, 585 structure, 4, 552... 

The nucleophilic aromatic substitution reaction for the synthesis of poly(arylene ether ketone)s is similar to that of polysulfone, involving aromatic dihalides and aromatic diphenolates. Since carbonyl is a weaker electron-withdrawing group titan sulfonyl, in most cases, difluorides need to be used to afford high-molecular-weight polymers. Typically potassium carbonate is used as a base to avoid the... 

AABB polyimides, synthesis of, 300-302 AA-BB-type polymers, 135 AA-BB-type sulfonylation, 330 AA monomers, 11-12 A-B-A triblock copolymers, 7 A-B copolymers, 7 AxBy monomers, 8 AB polyamides, 173-180 AB polyimides, 304-307 syntheses of, 306 Abrasion resistance test, 243-244 ABS. See Acrylonitrile-... 

A catch and release synthesis of tetrazoles and cyclic amidines has been reported making use of solid-supported oximes [94]. When bound sulpho-nyloximes, obtained by reacting polymer supported sulfonyl chloride with oximes, were reacted with nucleophiles, tetrazoles or cychc amidines were obtained (Scheme 19). Alternatively, the use of TMS-CN affords imino nitriles, which have been used as intermediates for the preparation of indoles, 1,2,3,4-tetrahydropyridines, quinoxalines and benzimidazoles. 

Besides short ELPS, longer ELPs have also been conjugated to synthetic polymers. In one approach, Cu(I)-catalyzed azide-alkyne cycloaddition click chemistry was applied. For this purpose, ELPs were functionalized with azides or alkynes via incorporation of azidohomoalanine and homopropargyl glycine, respectively, using residue-specific replacement of methionine in ELP via bacterial expression [133]. More recently, an alternative way to site-selectively introduce azides into ELPs was developed. Here, an aqueous diazotransfer reaction was performed directly onto ELP[V5L2G3-90] using imidazole-1-sulfonyl azide [134]. 

The chemical modification of poly (2,6-dimethyl-l,4-phenylene oxide) (PPO) by several polymer analogous reactions is presented. The chemical modification was accomplished by the electrophilic substitution reactions such as bromination, sulfonylation and acylation. The permeability to gases of the PPO and of the resulting modified polymers is discussed. Very good permeation properties to gases, better than for PPO were obtained for the modified structures. The thermal behavior of the substituted polymers resembled more or less the properties of the parent polymer while their solution behavior exhibited considerable differences. 

In our research, three chemical modification approaches were investigated bromination, sulfonylation, and acylation on the aromatic ring. The specific objective of this paper is to present the chemical modification on the PPO backbone by a variety of electrophilic substitution reactions and to examine the features that distinguish modified PPO from unmodified PPO with respect to gas permeation properties, polymer solubility and thermal behavior. 

Materials. The starting PPO was purchased from Aldrich Chemical Co. Two reprecipitations from chloroform into methanol served to purify the polymer. The bromine, chlorosulfonic acid, sulfonyl chlorides, acid chlorides as well as all other reagents and solvents were purchased from Aldrich Chemical Co. and were used without further purification. 

---