The dispersion of polymeric materials with the use of supercritical fluids

Abstract

The dispersion of polyisobutylene was studied on a Thar RESS-100-2 test bench over the temperature and pressure ranges 45–120°C and 100–350 bar; 30–1000 nm particles were obtained. Particle size could be controlled by varying process parameters. A procedure for modifying polymer particles during rapid expansion of supercritical solutions was suggested. Modification suppressed agglomeration and caused particle coating with a modifier (NaCl). The use of supercritical fluid antisolvents was shown to be promising for the dispersion of polymers to nanosized particles. An experimental bench for performing such processes was described. A procedure for trapping nanoparticles prepared using antisolvents was suggested. Particles with sizes of 10 to 150 nm were obtained in the dispersion of polystyrene in the toluene-polystyrene-supercritical carbon dioxide system at 40–150 bar and temperatures of 40 and 100°C.