Abstract: A polymeric bead has now been developed to act as a support for other entities having a volume mean diameter of up to 250 microns and having a surface provided with pores which form at least 10% by area of the surface. At least one third of the total area of the pores is provided by pores having a larger size of at least 0.4 micron. A method for the manufacture of such polymeric beads involves using a water-in-oil-in-water emulsion technique in which the amount of water used in the preparation of the aqueous phase is not greater than 125 parts by weight per 265 parts by weight of the mixture of the polyester resin and monomer which is used.The porous beads provide an excellent base for carrying enzymes, bacteria and catalysts species useful in a wide range of applications.

Abstract: A process for the preparation of rigid beads, of cross-linked polyester resin which beads may be solid or vesiculated, by forming an oil-in-water or a water-in-oil-in-water emulsion in which the oil phase contains an unsaturated polyester resin and an unsaturated organic monomer to provide said cross-linking and thereafter heating the emulsion to a temperature of at least 45.degree. C. before initiating polymerization of the oil phase by the introduction into the system of a polymerization initiator, and promoter system, if the latter is not already present in the emulsion.