Abstract: A process of preparing water soluble or water swellable polymer comprising the steps: a) forming an aqueous mixture comprising, i) a water soluble ethylenically unsaturated monomer or blend of monomers and, ii) at least one first ultra-violet initiator, iii) at least one second ultra-violet initiator; b) effecting polymerisation by subjecting the aqueous mixture formed in step (a) to irradiation by ultraviolet light at an intensity of up to 1,000 &mgr;Wcm−2; subjecting the product of step (b) to irradiation by ultraviolet light of greater than 1,000 &mgr;Wcm−2, characterised in that a significant amount of the first initiator(s) is/are activated in step (b) and a significant amount of the second initiator(s) is/are activated in step (c). The process is particularly suitable for making highly effective water soluble and water swellable polymers useful as flocculants, coagulants, rheology modifiers, dispersants, superabsorbents and binders etc.

Abstract: Beads are made from water-soluble monomer or monomer blend by reverse phase bead polymerization by extruding aqueous monomer beads into or onto the top of an upflowing column of non-aqueous liquid and the beads polymerise as they float downwardly through the column during a period of at least ½ minute. The resultant beads can have a very narrow particle size distribution.

Abstract: Reverse phase polymer particles having a size below 10 .mu.m are provided as a solid product comprising a solid dispersion of the particles in a wax matrix which is solid at 20.degree. C. and which melts below 250.degree. C. The product may be made by dissolving the wax into the organic liquid phase of the product of a reverse phase emulsion polymerisation process followed by distillation of the organic liquid and cooling of the resultant product. The product is generally in particulate form and can be used as a flocculant or viscosifier, especially as a textile print paste thickener.

Abstract: A flocculant, viscosifier or other water soluble or water swellable particulate polymer is formulated as a block having a dimension of at least 10 mm and which comprises a wax matrix in which the polymer particles are dispersed. The block can be made by blending polymer powder with the molten wax matrix and cooling and solidifying it. The block is of particular value for releasing flocculant into a flowing stream of suspension.