Sulphonated styrene

Sulphonated styrene divinylbenzene cross-linked polymers are used as cation exchange resins. Disadvantages... 

The majority of kinetic studies of ester hydrolyses using this type of catalyst were performed with sulphonated styrene—divinylbenzene copolymers. Only in a few cases [476—478] was the use of phenol—formalde-... 

M 15. — — — — Solvent-modified polymer networks. Part II. Effect of structure on cation-exchange kinetics in sulphonated styrene-divinyibenzene copolymers. J. Chem. Soc.T963, 2779. 

Zeohtes also have considerable application as catalysts. Iron in the +3 oxidation state is introduced by ion-exchange methods [103]. However, attempted adsorption of Fe " " ions causes complete breakdown of the structure with any retained iron being in the +3 state. Dehydration of the zeolite causes non-reversible reduction of the iron. Adsorption of Fe salts on ion-exchange resins of the sulphonated styrene-divinyl benzene and quaternary ammonium types has httle effect on the iron resonances and indicates very weak binding of the ions to the resin [104]. Spin-relaxation effects and temperature-dependent paramagnetic hyperfine structure have been recorded and interpreted in detail for Fe ions adsorbed on exchange resins [105, 106], and a number of other recent papers have shown interest in this new field [107]. 

The proposed sulphonation reaction in radiation induced styrene grafted natural rubber, and the structure of the ionomer (zinc sulphonated styrene grafted natural rubber), are shown in Scheme 14.1 and Scheme 14.2. The... 

Butadiene-styrene 89 Disodium hydrogen phosphate Sulphonated styrene-divinyl... 

Strong acid anionic resins such as sulphonated styrene-divinyl benzene copolymers can be used to mask the taste of basic drugs with a bitter taste. They can be used almost throughout the entire physiological pH range above... 

Figure 4.29 Sulphonated styrene-divinylbenzene copolymer complex with chlorphen amine.

The diffusion of cyclohexa-amylose and cyclohepta-amylose (a- and /3-cyclodextrin) has been studied in aqueous solutions of poly(methacrylic acid), sodium poly(styrene sulphonate) and co-poly(styrene-methacrylic acid). A decrease in the diffusion coefficients of the cycloamyloses in these polymer solutions was found to be dependent on the polymer concentration, degree of sulphonation, styrene content, and degree of neutralization. The results were interpreted assuming a 1 1 complex between the cycloamylose and an appropriate residue in the polymer. 

Resins such as phenol formaldehyde and highly sulphonated styrene/divinyl benzene macroporous ion exchange resins can be pyrolysed to produce carbonaceous adsorbents which have macro-, meso- and microporosity. Surface areas may range up to 1100 m /g. These adsorbents tend to be more hydrophobic than granular activated carbon and therefore one important application is the removal of organic compounds from water. 

The benzene nucleus in polystyrene undergoes normal aromatic reactions and thus the polymer may be, for example, alkylated, halogenated, nitrated and sulphonated. A frequent practical difficulty in carrying out such reactions is one of finding a reaction medium in which the polymer is soluble also, chain scission, cross-linking and discoloration often accompany these reactions. Chemically-modified polystyrenes have found little commercial application but sulphonated styrene-divinylbenzene copolymers (which are cross-linked) find use as cationic exchange resins the nature of such resins is illustrated by the following strueture ... 

Poly(ethylene terephtlhalate) Phenol-formaldehyde Polyimide Polyisobutylene Poly(methyl methacrylate), acrylic Poly-4-methylpentene-1 Polyoxymethylene polyformaldehyde, acetal Polypropylene Polyphenylene ether Polyphenylene oxide Poly(phenylene sulphide) Poly(phenylene sulphone) Polystyrene Polysulfone Polytetrafluoroethylene Polyurethane Poly(vinyl acetate) Poly(vinyl alcohol) Poly(vinyl butyral) Poly(vinyl chloride) Poly(vinylidene chloride) Poly(vinylidene fluoride) Poly(vinyl formal) Polyvinylcarbazole Styrene Acrylonitrile Styrene butadiene rubber Styrene-butadiene-styrene Urea-formaldehyde Unsaturated polyester... 

Macroazoinimers were used in the dispersion polymerization of styrene in water without using any additional emulsifier or initiator [52,53]. Sulphonation of the styrene-PEG crosslinked block copolymer can be used... 

A widely used cation exchange resin is that obtained by the copolymerisation of styrene (A) and a small proportion of di vinyl benzene (B), followed by sulphonation it may be represented as (C) ... 

However, the discovery with the most far-reaching consequences arose from the close scrutiny of the results of Kunitake and Takarabe on the polymerisation of styrene by trifluoromethyl sulphonic acid. It became evident to the reviewer that in these reactions an important contribution to monomer consumption must have been made by the ester, and he was able to extract from the results the corresponding propagation rate-constants, kpu, for that cationoid insertion polymerisation. This became one of the most convincing supports for the author s views on cationoid insertions. 

So, the PVA/poly(sodium styrene sulphonate) [PSSNa] blend was obtained by casting aqueous solution of polymers mixture (PVA with Mw= 124,000-186,000 and HD=99% and PSSNa with Mw= 70,000). The resulted films were crosslinked with 1,2-dibromethane in gaseous phase. A semi-interpenetrating network (SIPN) in which polyelectrolyte (PSSNa) chains are trapped inside a based PVA network was obtained [44], A totally miscible blend with a very good film clarity and high mechanical resistance [44] resulted. 

In Table III the specific conductance and electro-osmotic coefficient (3) for the SPS membrane are shown together with the data for a conventional ion-exchange membrane, AMF C103 (16,17) (polyethylene-styrene graft copolymer containing sulphonic acid groups). It appears that there is a close similarity in properties of both membranes. ... 

With one exception [447], only sulphonated resins were used as catalysts in kinetic studies of esterification and transesterification, the resins being almost exclusively styrene—divinylbenzene copolymers in one case, a sulphonated phenol—formaldehyde resin was also used [433]. The main factors determining the catalytic activity are (i) the concentration of functional groups in protonated form (— S03H groups) and (ii) the degree of crosslinking of the copolymer (characterised by the divinylbenzene content). 

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