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A commercial packing polystyrene had been modified via sulphonation process yielding an efficient ion-exchanger for softening of water . Some factors that have to do with such transformation had been followed up . It had been found that sulphonation conditions, molecular weight, residence time and additives have roles to play.

Pathological crystallization of calcium oxalate (CaOx) inside the urinary tract is called calculi or kidney stone (Urolithiasis). CaOx exhibits three crystalline types in nature: CaOx monohydrate COM, dihydrate COD and trihydrate COT. COD and COM are often found in urinary calculi, particularly COM. Langmuir monolayers, membrane vesicles, phospholipids' micelles, among others, have been adopted as simplified biomimetic template-models to study in vitro the urolithiasis through CaOx. The nucleation and crystal growth of COM on self-assembled lipid monolayers have revealed that the negatively charged phosphatidylserine interface is a strong promoter of COM. Herein, we describe the synthesis and physicochemical characterization of diazotated sulphonated polystyrene films (DSPFs), prepared from various aminocompounds varying their polarity degree i.e., polar, non-polar and acidic DSPF derivatives. We also used these DSPFs as polymeric templates in crystallization experiments of CaOx in vitro. Images obtained by optical microscopy and scanning electron microscopy confirmed the precipitation of COM crystals on the DSPF surface. The employment of functionalized polymeric films as templates for CaOx crystallization represents a viable approach for understanding inorganic mineralization. [ABSTRACT FROM AUTHOR]

Abstract: Sulphonated polystyrene butadiene rubber/carbon nanoballs (SPSBR/CNBs) composites proton exchange membrane was developed by sulphonation of polystyrene butadiene rubber using chlorosulphonic acid as the sulphonating agent. The sulphonated rubber was then blended with non-catalytic carbon nanoballs (CNBs) produced by swirled floating catalytic chemical fluid deposition (SFCCVD) method. The SPSBR/CNBs composites proton exchange membrane was characterized to determine the thermal stability, water uptake, porosity and proton conductivity. The results obtained revealed that blending of the membrane with CNBs improved the thermal stability, water uptake retention and proton conductivity of the membrane with about 50% increase in proton conductivity. The synthesized and composite membranes were sandwiched between two electrodes to produce a membrane electrode assembly (MEA). The performance of the fabricated MEA was tested in a single PEM fuel cell using hydrogen as the fuel gas and oxygen as oxidant .The results obtained revealed that the utilization of SPSBR-CNBs composite proton exchange membrane resulted in higher performance compared to Nafion 112. Nafion 112 produced a maximum power density of 66.9 mW/cm2, while the developed membrane gave a maximum power density in the range of 73.7-97.1 mW/cm2depending on the mass of CNBs. [Copyright &y& Elsevier]

Chemical modification of polymeric materials is one way of polymer waste management. In our study, expanded polystyrene waste (EPS), used as the reference material, was converted into polymeric flocculants by the sulphonation reaction. Thus, poly(styrenesulphonate) acids (EPSS) were obtained from EPS during the sulphonation process with sulphuric acid as the sulphonation agent and Ag2SO4 as the catalyst under both conventional heating and microwave conditions. At the termination of the process the products were precipitated in the form of sodium salts (NaEPSS) in the reaction with Na2CO3 and their characteristics were given. The influence of temperature and time of reaction on the properties of EPSS and NaEPSS was studied and compared with conventional and microwave conditions. The results showed that the sulphonation process performed under microwave irradiation allowed us to receive products with properties similar to the ones obtained under conventional conditions but the reaction time was substantially reduced from 1 and ½ hour to 15 min. [ABSTRACT FROM AUTHOR]

Abstract: One of the ways of polymer waste management is its chemical modification. Waste polystyrene foam (EPS) and virgin polystyrene (VPS) as a reference material were converted into polymeric flocculants by chemical reactions. Poly(styrene sulphonate) acids (EPSS and VPSS) were obtained from EPS and VPS during the sulphonation process with sulphuric acid as the sulphonating agent and Ag2SO4 as the catalyst. Products were precipitated in the form of sodium salt (NaEPSS, NaVPSS) in the reaction with Na2CO3. The influence of temperature and the time of reaction on the properties of the products were studied. Products with determined molecular weight and number of sulphonic group per monomer units were divided into several fractions by fractional precipitation with 0.5M aqueous NaOH as the solvent and 2-propanol as the precipitant. The products were successfully used as flocculants in the treatment of the waste water discharge model colloid system, iron (III) hydroxide, which is comparable with industrial waste and water from mining companies and galvanising plants. The application of the obtained products caused a significant decrease in turbidity of the studied solutions. It was also found that the effectiveness of the flocculation depends on the number of sulphonic groups per monomer unit and the molecular weight of the polyelectrolytes. [Copyright &y& Elsevier]