PROCESS TO PREPARE LOW DENSITY POROUS CROSS-LINKED POLYMERIC MATERIALS

摘要

Stable high internal phase water-in-oil emulsions containing polymerizable vinyl monomers, cross-linking monomers and initiators are obtained useful in producing low density porous cross-linked polymeric materials by using a surfactant system containing (a) one or more sorbitan fatty acid esters or saccharide fatty acid esters or mixtures thereof and (b) one or more quaternary salts having one or more greater than or equal to 8 carbon atom hydrocarbon groups. A water-in-oil emulsion can be formed with lower surfactant concentration than sorbitan fatty acid ester alone and improved surfactant performance at elevated temperatures is obtained. Sludge formation otherwise observed with the use of sorbitan fatty acid ester surfactants is also reduced or eliminated.