Abstract: Dirt tracks and other surfaces formed of particulate material are stabilized, to suppress dust formation, by incorporating an aqueous solution of a water soluble, low molecular weight, anionic polymer.

Abstract: Solid material is ground in a grinding mill and caking of the ground particles is substantially eliminated by including particulate water absorbent polymeric material in the mill.

Abstract: Water absorbent, water insoluble, cross linked polymer fibre or film can be made by dry extrusion of a solution of a substantially linear polymer formed from a water soluble blend of monoethylenically unsaturated monomers comprising a plasticizing monomer, evaporating the solvent and forming polymeric fibre or film plasticized by an external plasticizer, stretching the fibre or film while the external plasticizer remains in the fibre or film, and then cross linking the polymer.

Abstract: A concentrate composition, that can be diluted with water to form an aqueous size for cellulosic fibres, comprises a substantially anhydrous dispersion of polyelectrolyte particles in a non-aqueous liquid comprising a reactive size, and is made by forming a dispersion in a hydrophobic liquid of the polyelectrolyte particles while they are swollen by water, azeotroping the dispersion and adding the size to the hydrophoboic liquid. If the size is a liquid size, the hydrophobic liquid may be removed from the composition. The dispersion of swollen polyelectrolyte particles in the hydrophobic liquid can be amde by dispersing a solution of polyelectrolyte in the liquid but is preferably made by reverse phase polymerization.

Abstract: A slow release composition comprises particles of a cross linked polymeric matrix in which a water soluble reagent is dispersed, and the reagent is anionic, generally being a low molecular weight anionic water soluble polymer, and the matrix is a cationic, highly cross linked, polymer formed from a water soluble monomer or monomer blend.

Abstract: A homogenous blend is formed of different water soluble polymer types, for instance of particular addition and condensation polymers, by forming one of the polymers from its monomeric starting material by polymerisation in a solution of the other polyer. The resultant solution has a concentration of above 10% but is homogenous. It can be used as a bulk solution or can be dried to powder or can be present as a reverse phase dispersion.

Abstract: When making an unsaturated amide by hydrolysis of an unsaturated nitrile in the presence of a catalyst such as Raney copper and an oxidizing agent such as copper nitrate, by-product formation is reduced by including a reagent selected from reducing agents and acids that are substantially non-oxidizing relative to the said oxidizing agent. The preferred reagents are acidic buffers, especially acetic acid and copper acetate. Washing with such a buffer a Raney catalyst or other catalyst that is to be used for catalyzing the hydrolysis of an unsaturated nitrile to an unsaturated amide reduces the temperature surge that otherwise occurs upon addition of the catalyst to the reaction mixture.

Abstract: An aqueous organic or inorganic suspension can be coagulated and then flocculated by flowing it past a shaped body comprising a mixture of water soluble multivalent metal coagulant and a water soluble organic polymeric flocculant in the form of substantially discrete particles. The surface of the shaped body is eroded by the flowing stream to form a solution of the coagulant in which the polymeric flocculant particles are entrained, and these subsequently dissolve into the suspension.

Abstract: Measurement of the ionic value X of a solution of a polyelectrolyte after shearing, for instance by a rotating blade, and/or measurement of the ionic value Y of a solution of polyelectrolyte before shearing, and especially the difference between t he values X and Y, gives a useful indication of the degree of cross linking of the polyelectrolyte and so can be utilized to control the manufacture of the polyelectrolyte, for instance drying conditions, or the storage or use of the polyelectrolyte, for instance its suitability or dosage in a flocculation process.

Abstract: Powdered polysaccharide may be made by spray drying an emulsion in a non-aqueous liquid of an aqueous solution of the polysaccharide. Spray dried polysaccharides are novel materials. At least 90% by weight of the particles may be within a size range of not more than 100 microns. The particles may have an average size between 50 and 250 microns or between 10 and 50 microns, and the finer particles can be redispersed into oil.

Abstract: A Mannich base of a high molecular weight acrylamide polymer can be made by reacting, in aqueous solution, the polymer with a Mannich base of a low molecular weight compound such as urea. A composition of the polymer and the Mannich base is preferably substantially non-aqueous.

Abstract: The clarification of a sodium aluminate liquor in the Bayer Process, especially the liquor obtained by Kelly filter filtration of the supernatant from the primary settling stage, is improved by flocculation with a polymer of the formula CH.sub.2 .dbd.C(R.sup.1)CONHR.sup.2 NR.sup.3 R.sup.4 wherein R.sup.1 is hydrogen or methyl, R.sup.2 is straight or branched chain C.sub.2-8 alkylene having at least 2 carbon atoms in the backbone and R.sup.3 and R.sup.4 are independently selected from C.sub.1-4 alkyl.

Abstract: Dispersions in water-immiscible liquid of water-soluble or water-swellable polymer particles are stabilized by use of an aqueous emulsion of water insoluble viscosifying polymer particles that are swellable or soluble in the water-immiscible liquid. After adding the emulsion to the water-immiscible liquid, water is removed from around the particles of the viscosifying polymer, preferably by absorption into the water swellable or soluble polymer particles. Water-immiscible liquids in general can be thickened particularly effectively by use of an aqueous emulsion of water insoluble viscosifying polymer particles that are swellable but insoluble in the water-immiscible liquid. These insoluble particles have a dry size below 10 .mu.m and are formed from monomers of which 80 to 100% are hydrophobic, 30 to 100% are polar and hydrophobic, 0 to 20% are hydrophilic and not more than 30% by weight are aromatic.

Abstract: A cross linked high molecular weight polymer formed from a water soluble monomer or blend of monomers and which has IV and/or solubility and/or rheology properties indicating that it would be unsuitable for use as a flocculant can be used as a flocculant after shearing the polymeric material. The shearing may be applied to the polymeric material before addition to the suspension that is to be flocculated or can be applied to the suspensionthat is being flocculated. The shearing increases the intrinsic viscosity of the polymeric material and can improve its rheology and solubility. The polymeric material must be of high molecular weight.

Abstract: Polymers having recurring units derived from monomers of formula ICH.sub.2 .dbd.C(R.sup.1) CONHR.sup.2 NR.sup.3 R.sup.4 Iwherein R.sup.1 is hydrogen or methyl, R.sup.2 is straight or branched chain C.sub.2-8 alkylene having at least 2 carbon atoms in the backbone and R.sup.3 and R.sup.4 are independently selected from C.sub.1-4 alkyl, most preferably quaternized dimethylaminopropyl methacrylamide polymers, for instance copolymerized with acrylamide, are used as flocculating agents in processes where the polymer is present during part at least of the process in solution in the presence of free chlorine.

Abstract: When flocculating an aqueous suspension of suspended solids using a high molecular weight synthetic polymeric flocculant, the shear stability of the flocs is increased if the polymeric material includes polymeric particles of below 10 .mu.m dry size. The flocculated solids can therefore be subjected to shear without increasing the amount of discrete suspended solids in the aqueous medium and generally they are subjected to shear by shearing the aqueous medium containing them, either before dewatering, generally on a centrifuge, piston press or belt press, or by continuously agitating them, for instance in a chemical reaction medium. The polymeric material is generally formed by mixing into water polymeric particles made by reverse phase or emulsion polymerization in the presence of added cross linking agent. Alternatively, particles insolubilized by insoluble monomer may be used. A reverse phase dispersion of water soluble polymer may be used if the particles remain undissolved, e.g.

Abstract: A thermal energy storage composition is formed of a thermal energy storage hydrate and a solid, water swellable, thermally conducting polymer by blending particles of the polymer with the thermal energy storage hydrate.

Abstract: A soil sealing composition suitable for reducing the permeability of soil to water contaminated with electrolyte comprises an expanding lattice clay and a water soluble or water swellable polymer having a molecular weight of at least 500,000 and that is a copolymer of 2-acrylamido-2-methyl propane sulphonic acid, or certain other ethylenically unsaturated sulphonic acids, together with other ethylenically unsaturated monomer, preferably a blend of acrylamide and acrylic acid.

Abstract: Water-immiscible liquids, for example oil-based drilling fluids, are thickened by the addition of an aqueous dispersion of polymeric particles that are water-insoluble, and insoluble but swellable polymer, in the water immiscible liquid. The particles have a unswollen average diameter of less than 10 .mu.m and at least 30% by weight are preferably in the range 0.5 to 5 .mu.m. Preferred polymers are formed from more than 80% by weight hydrophobic monomers, preferably alkyl (meth) acrylates, and up to 20% hydrophilic monomers, preferably unsaturated carboxylic acids, preferably acrylic acid.

Abstract: Beads comprising a polymeric matrix containing a releasable lipophilic compound are made by precipitating the compound from solution within the matrix. Beads may be made by forming a homogeneous blend of the compound in lipophilic polymerizable material and subjecting the blend to bead polymerization while the blend is dispersed as beads in an aqueous medium containing hydrophilic polymerization stabilizer. The lipophilic compound may be a behenyl ester wax inhibitor or other reagent useful downhole or for other purposes and preferably has a relatively high melting point. The polymerizable material preferably dissolves the lipophilic compound and may include acrylic acid, methacrylic acid or other hydrophilic polymerizable material.