SYNTHESIS OF CRITICALLY CROSS-LINKED MICROGELS BY DISPERSION POLYMERIZATION

Microgels with cross-link densities close to the critical value of gel transition are synthesized via polymerization in microemulsion stabil ized with a polymeric surfactant. The resulting structures are charact erized by static and dynamic light scattering, viscometry, small angle neutron scattering and dynamic-mechanical shear experiments. The prox imity of the gel point influences the different properties in a differ ent way. Global properties such as particle shape are closely connecte d with the gel point whereas the local structure and relaxation show c ritical behavior even quite far from the gel point.