摘要 |
<p>The material is in the form of spheroidal granules, each consisting of a thermoplastic polymeric matrix (1) and of a denser adjuvant in the form of microparticles (3) dispersed in the said matrix. At the surface each granule has a porosity in the form of microcells (4) and of cationic hydrophilic sites (6) distributed over the surface. The material is manufactured by mixing an oxidisable thermoplastic resin with an adjuvant in powder form, heating the mixture to make it plastic, extruding it at a diameter corresponding to the size of the granules to be obtained, sectioning it in lengths equal to this diameter, converting the said lengths into pearls, carrying out a surface oxidation of the spheroidal granules thus obtained and then grafting a polyelectrolyte of cationic type by an ionic route at the surface of the said granules. …<IMAGE>… </p> |