Potassium persulphate, preparation

A polyacrylamide with a molecular mass of 1.87 x 105 was prepared by polymerising a 5% w/v aqueous solution of acrylamide monomer in the presence of 0.15% w/w benzyl alcohol and 0.025% w/w potassium persulphate for 45 minutes at 80 °C. This product was effective in preventing the bleeding of direct dyes and hydrolysed reactive dyes from dyed cotton, which was simply dipped in a 1% solution of the polyacrylamide and dried in air [450]. 

By far the most studied PolyHIPE system is the styrene/divinylbenzene (DVB) material. This was the main subject of Barby and Haq s patent to Unilever in 1982 [128], HIPEs of an aqueous phase in a mixture of styrene, DVB and nonionic surfactant were prepared. Both water-soluble (e.g. potassium persulphate) and oil-soluble (2,2 -azo-bis-isobutyronitrile, AIBN) initiators were employed, and polymerisation was carried out by heating the emulsion in a sealed plastic container, typically for 24 hours at 50°C. This yielded a solid, crosslinked, monolithic polymer material, with the aqueous dispersed phase retained inside the porous microstructure. On exhaustive extraction of the material in a Soxhlet with a lower alcohol, followed by drying in vacuo, a low-density polystyrene foam was produced, with a permanent, macroporous, open-cellular structure of very high porosity (Fig. 11). 

Preparation of Potassium Persulphate. Assemble an apparatus shown in Fig. 74. Put 100 ml of a potassium bisulphate solution saturated at 0 °C (see Appendix 1, Table 1) into test tube 1. Immerse... 

Preparation and Properties of Bismuth (V) Compounds. 1. Precipitate bismuth(III) hydroxide in a test tube and treat it with a saturated potassium persulphate solution (2-3 ml) while heating it. What happens Write the equation of the reaction. Wash the precipitate three times with water by decantation. 

The explosive properties of peroxides have attracted attention for a long time, mainly because of their initiating properties namely, in a confined space burning readily passes into detonation. In spite of this, virtually none of the peroxides has found practical application. Some are rather unstable, others are very volatile and all are highly sensitive to friction and impact e.g. acetone peroxide, very easily prepared by the action of potassium persulphate on acetone in the presence of sulphuric acid (Baeyer and Villiger [82]) possesses, according to T. Urbanski s [83]... 

The trinitro-m-toluidine thus obtained is oxidized in sulphuric acid solution with potassium persulphate. The yield of this stage of the reaction is about 85% of theory. The tetranitrotoluene thus prepared may then be recrystallized from nitric acid of a sp. gr. of 1.40. 

II. From Per-Acids.—Another process smted to the economical preparation of hydrogen peroxide is based on the decomposition of permonosulphuric acid under the influence of water. The acid, prepared by the electrolysis of sulphuric acid or by the interaction of potassium persulphate and sulphuric acid, undergoes gradual hydrolysis according to the equation... 

Cobalto-cobaltic oxide has been prepared in three states of hydration. The trihydrate, Co304.3H20, results on warming cobaltous hydroxide with potassium persulphate and heating the resulting product to 100° C. with dilute nitric acid.1 It is also produced as a brown precipitate on boiling a solution of roseo-cobaltic sulphate. 

An elegant example of the analysis of colloid surfaces containing covalently attached hydrophilic species has been provided by Brindley et al who studied the surface chemistry of polystyrene colloids with surface grafted polyethylene glycol groups [39]. These colloids were prepared by surfactant-free copolymerization of styrene with PEG using potassium persulphate as an initiator. The XPS analysis of these microparticles is shown in Fig. 11. 

To assess the effect of an adsorbed layer of polyvinyl alcohol on the rate of polymerisation, the rates of seeded polymerisation were measured after adsorption of various grades of polyvinyl ailcohol on the seed latex. The seed latex was prepared in the same way as the latex used in the adsorption experiments. After adsorption of polyvinyl alcohol from a 0.10 % w/v solution, the concentration of the seed latex wets 0.9A5 % w/v in a 2.0 % v/v vinyl acetate solution containing 7.4 x 10" mol dm" potassium persulphate. The rates of polymerisation (the means of two to four experiments) observed at 60 C are tabulated below. 

The condensation method begins with molecular units, and the particles are built-up by a process of nucleation typical example is the preparation of polymer lattices, in which case the monomer (e.g., styrene or methylmethacrylate) is emulsified in water using an anionic or nonionic surfactant (e.g., sodium dodecyl sulphate or alcohol ethoxylate). A polymeric surfactant is also added to ensure the long-term colloid stabiHty of the resulting latex. An initiator such as potassium persulphate is then added and, when the temperature of the system has increased, initiation occurs that results in formation of the latex [polystyrene or poly(methylmethacrylate)]. 

A novel graft copolymer of hydrophobically modified inuhn (INUTEC SPl) has been used in the emulsion polymerisation of styrene, MMA, butyl acrylate, and several other monomers [8]. All lattices were prepared by emulsion polymerisation, using potassium persulphate as initiator, and the z-average particle size was determined using PCS electron micrographs were also recorded. 

SiUcone-modified styrene-butyl acrylate copolymer latex was synthesised by emulsion copolymerisation using octamethylcyclotetrasiloxane(D4), styrene and butyl acrylate as raw materials, potassium persulphate as initiator and propylmethacrylate triethoxysilane as crosslinking agent. The IR spectroscopic studies showed that the vinyl monomers were completely copolymerised with D4. The prepared silicone-modified copolymer latex with the IPNs tended to have higher stability and better toluene and water resistance than styrene-butyl acrylate copolymer latex. The glossiness of coated paper was improved with silicone-modified copolymer latex and it was at a maximum when D4 was about 3% of total monomers. 16 refs. 

Details are given of the preparation of SAN latexes by micro-emulsion polymerisation using sodium dodecyl sulphate as an anionic surfactant. Kinetics of copolymerisation was studied at different temperatures using different concentrations of potassium persulphate and hydrogen peroxide/ascorbic acid. The latexes were characterised for particle size and number of particles by dynamic light scattering and TEM. Products were examined using NMR and thermal analysis. 20 refs. INDIA... 

The above latices were prepared by batch precipitation polymerisation of N-isopropylmethacrylamide using methylenebisacrylamide, as crosslinker, and potassium persulphate, as polymerisation initiator. The effect of the crosslinker on total conversion of polymer, latex particle size and morphological properties and colloidal properties of the final microgel particles were investigated. The relationship between the amount of water-soluble polymer and amount of crosslinker and the influence of temperature on the electrophoretic mobility of the latex are considered. 11 refs. 

Details are given of the preparation of pH sensitive hydroxyethyl methacrylate-dimethylaminoethyl methacrylate copolymer hydrogels initiated by potassium persulphate in an aqueous medium. Data are given for morphology and swelling in water. 22 refs. 

Copolymer latices of styrene and acrylates (mainly butyl acrylate) were synthesised. Sodium dodecyl sulphate and ethoxylated nonyl phenol containing ten ethylene oxide units were used as surfactants and potassium persulphate as initiator. A coating for paper was made on the basis of the copolymer latices and white pigments. The performance of the coated paper was measured. By varying experimental conditions such as comonomer proportion and amounts of emulsifiers and of initiator, a copolymer latex suitable for paper coating was prepared. Paper coated with latex showed satisfactory properties in... 

The annlsion polymerisation is described of styrene-vinyl acetate with different molar ratios using a redox initiator system (potassium persulphate/sodium bisulphite) and their film forming was investigated. Latices were prepared with high solids content having good properties for nse in snrface coatings as interior and exterior paints. 13 refs. 

Heterogeneous latices were prepared by a two-stage seeded emulsion polymerisation process at 80C using potassium persulphate as initiator and sodium dodecyl sulphate as emulsifier. Styrene-methacrylic acid (MAA) copolymer latices containing varying amounts of MAA were used as seeds. The second stage polymerisation was performed either as a seeded batch process or as a seeded... 

Conventional free radical techniques are applicable and conunonly solution polymerization is carried out, using water as the solvent. In a typical process a water-soluble initiator such as potassium persulphate is added to an aqueous solution of the acid together with an activator, e.g., sodium thiosulphate, and a transfer agent, e.g., mercaptosuccinic acid a reaction temperature of 50 100°C is used. Alternatively, if solid polymer is required, it is convenient to conduct the polymerization in a solvent such as benzene in which the polymer is insoluble in this case benzoyl peroxide is a suitable initiator. Salts of acrylic and methacrylic acids may also be polymerized in aqueous solution by treatment with free radical initiators. In addition to the polymerization of the appropriate monomer, the hydrolysis of a suitable polymer represents a further method of preparation of polymeric acids and salts. (See Sections 6.4,6.6.3 and 6.7.)... 

Primary alcohols and aldehydes can also be eflBciently oxidized to acids by catalytic amounts of potassium ruthenate (K2[Ru04]) in the presence of potassium persulphate and aqueous alkali. This method is amenable to large-scale reactions, and seems especially suitable for the preparation of unsaturated and aromatic acids. 

Using purest potassium or ammonium persulphate prepare 0.03 M solution. Pipette 25.0 cm of the solution into a 250 cm conical flask, add 3 cm of H3PO4 (syrupy), 10 cm dil. H2SO4 and 25.0 cm of 0.100 mol dm of iron(II) solution. After 5 minutes, titrate the excess Fe(II) with 0.02M KMn04 solution to the first permanent faint pink colour. Repeat to obtain concordant results. 

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