| abstract |
The present invention is concerned with a process that allows the encapsulation of a polymerization accelerator, said process comprising the steps of: a) providing a reverse emulsion containing an oil phase, a solution in water / dispersion containing a polymerization activator ; The oil phase includes a thermally curable mixture of an isocyanate and a hydroxylated polyalkyl ethane or polyol, b) pouring the inverse emulsion into a water phase to make a multiple water / oil / water emulsion, which contains activator drops as the phase of internal water and then c) heating the multiple emulsion obtained in step b) at a temperature between 50 and 95 ° C, in order to cure the polyisocyanate in polyurethane and obtain activator drops enclosed in polyurethane covers dispersed in water . The invention also concerns aqueous gelation systems comprising the polymerization accelerator encapsulated with water soluble or dispersible monomers and a polymerization initiator dispersed in said monomers, useful i.a. for sealing underground environments or consolidating a floor or sealing an underground structure. |