Abstract: A water absorbing particulate polymer material wherein the polymer material when in dry powder form has a particle size of about 50 .mu.m to about 500 .mu.m and wherein the particles consist of internally bonded finer particles which finer particles have a size below 50 .mu.m. The process of using the water absorbing polymer, material to convert a wet sticky mass of inorganic particulate such as coal fines into a crumbly or flowable solid. A process using a water absorbing particulate polymer material to convert a wet sticky mass of organic particulate material into a crumbly or flowable solid wherein the organic matter can be, for example, food waste or sewage.

Abstract: Particulate water-soluble or water-swellable polymeric material is provided with a substantially uninterrupted continuous coating of crystalline material. Single particles or aggregates having a size below 1 mm in size can be made by mixing the polymeric particles with a substantially saturated or supersaturated aqueous solution of crystallizable material (optionally a melt of hydrate crystallizable material) and thereby depositing it as a continuous crystalline coating on the particles.

Abstract: High molecular weight polymer that can form a viscous aqueous solution is chemically modified by mixing the previously formed polymer (as a powder, reverse phase dispersion or oil-in-water emulsion) with water and the reagent for effecting the chemical modification so as to form a viscous aqueous mixture having a viscosity of at least 1OOO cps (Brookfield RVT) and then feeding this mixture as intermittent batches into one end of a tower through which it moves with substantially plug flow and from which it is withdrawn, at the end of the reaction, as intermittent batches. The apparatus for this purpose is also novel.

Abstract: A water absorbent water insoluble polymeric element, such as a fibre, film, coating, bonding layer or foam, is made by forming a substantially linear polymer by polymerisation of water soluble ethylenically unsaturated monomer blends comprising carboxylic and hydroxylic monomers and then reacting the carboxylic and hydroxylic monomers in the linear polymer to form internal cross links within the polymer.

Abstract: Water absorbent particulate polymers and their uses are described. Friable aggregates may be made by bonding substantially dry polymer particles with an aqueous liquid and drying the aggregates. These aggregates can be broken down to the individual polymer particles upon mixing with an aqueous medium and thus can have the flow properties of relatively coarse particles and the performance properties of relatively fine particles. They may be soluble nd used as flocculants or viscosifiers or binders for, for instance, iron ore pelletisation. Alternatively they may be swellable and insoluble, for instance for converting a sticky particulate mass (such as coal fines filter cake) to a crumbly solid.

Abstract: Novel polyvinyl alcohols include, in the polymeric backbone, vinyl units containing pendant hydrophobic groups. The polymers are made by hydrolysis of corresponding polyvinyl acylates under conditions are avoid hydrolysis of the pendant hydrophobic groups from the polymer. These groups are preferably bonded into the polymer as allyl ether units. The hydrophobic units act as internal plasticizers in films or other shaped articles formed from the polymers and, in particular, gives significant benefit in viscosity and other rheology characteristics of aqueous compositions formed from the polymer.

Abstract: Particulate metal ore is pellitized by use of a novel polymeric binder that comprises aggregates of polymer particles and that have a size mainly above 100 .mu.m and the aggregates are disintegrated during the process.

Abstract: Film or fibre is made from a polymer of water soluble ethylenically unsaturated monomeric material that includes ionic monomer by extrusion and stretching, and a counterionic lubricant compound is absorbed into the surface of the fibre or film before or during the stretching. The counterionic lubricant compound is also of use for providing a lubricated film on other extruded or comminuted elements of water swellable or water soluble polymeric material.

Abstract: The invention provides a substantially dry particulate composition comprising a polyacrylamide and an amidase. An aqueous composition made by dispersing this into water will then have a satisfactorily low content of residual acrylamide even if the initial polymer was contaminated with monomer. The composition is made by blending dry polyacrylamide particles with the amidase.

Abstract: The properties of absorptive synthetic polymer particles formed by polymerisation of water soluble monomers such as sodium acrylate or acrylamide with a cross linking agent are improved, especially as regards absorptive capacity for aqueous electrolytes, by copolymerising the monomers with an ethylenically unsaturated monomer that includes a pendant group --A.sub.m B.sub.n A.sub.p R where B is ethyleneoxy, n is at least 2, A is propyleneoxy or butyleneoxy, m and p are each less than n and are preferably zero, and R is a hydrophobic group.

Abstract: A water absorbent water insoluble polymeric element, such as fibre, film, coating, bonding layer or foam, is made by forming a substantially linear polymer by polymerization of water soluble ethylenically unsaturated monomer blends comprising carboxylic and hydroxylic monomers and then reacting the carboxylic and hydroxylic monomers in the linear polymer to form internal cross links within the polymer.

Abstract: Polymer thickeners suitable for use as textile pigment print paste thickeners are particulate cross linked polymers having a particle size of below 20 .mu.m and have defined physical characterization that indicates an optimum degree of cross linking and molecular size within the polymer.

Abstract: Acrylic acid or other unsaturated carboxylic acid is made by hydrolysing the corresponding nitrile in the presence of excess sulphuric acid to form amide sulphate, adding amide in an amount such that the total amount of amide and nitrile fed to the process is greater than 1 mole per mole sulphuric acid, hydrolysing the amide sulphate and amide to the desired acid and separating the acid from the sulphate by-products.

Abstract: An intimate water soluble or water swellable blend of microbial polysaccharide and synthetic polymer derived from water soluble monomer or monomer blend is made by forming an emulsion in non-aqueous liquid of an aqueous fermentation solution of the microbial polysaccharide and the monomer or monomer blend and then polymerizing the monomer or monomer blend to form a dispersion in non-aqueous liquid of aqueous particles of the water soluble or water swellable blend. This dispersion may then be dehydrated.

Abstract: When drying an aqueous polysaccharide solution, the viscosification properties are maintained, and often improved, by including a low molecular weight electrolyte in the solution before the drying is completed, and generally before the solution is heated above 50.degree. C.

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 suspended 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: Water soluble, substantially linear, polymers having single point intrinsic viscosity above about 3 are formed from an ethylenically unsaturated monomer that includes a group --B.sub.n A.sub.m R where A is propoxy or butoxy, B is ethoxy, n is zero or an integer of 2 to 100 and m is zero or an integer less than n, and R is a hydrophobic group of at least 8 carbon atoms and comonomer selected from non-ionic monomers and dialkylamino alkyl (meth) -acrylates or -acrylamides wherein at least one of the monomers is tertiary amine acid addition or quaternary ammonium salt. The resultant water soluble, high molecular weight, cationic polymers are useful as flocculants and as viscosifiers of aqueous acid solutions such as downhole acid stimulation fluids.

Abstract: A substantially dry, particulate polyacrylamide composition having reduced acrylamide monomer content is made by mixing amidase with coarse aqueous gel polymer particles, absorbing the amidase into the particles and subsequently drying the particles.

Abstract: A particulate mass that can be dusty but is generally sticky, due to the presence of water, is coverted to an apparently dry, non-dusty granular material by polymerizing a polymerizable material within the mass and breaking the mass down to the desired granular form after the polymerization has gone sufficiently far that the mass is substantially non-sticky but before the polymerization is completed.

Abstract: A wet filter cake of coal fines or other inorganic particulate material is converted to a crumbly mass by blending with water absorbent polymer particles.