KINETICS OF GEL FORMATION IN THE POLYACRY LONITRILE-PROPYLENE CARBONATE SYSTEM

The kinetic features af phase transformations leading to the formation of thermoreversible gels were studied in the system composed of a hig h-molecular-mass polyacrylonitrile (M-eta = 2.5 x 10(6)) and propylene carbonate. The time scale of the isothermal and nonisothermal process es of Formation and melting the of gels is established. It was shown t hat the thermal prehistory of a sample affects the pattern of gel melt ing in the systems containing 1.0, 2.5, and 5.0 wt % of polyacrylonitr ile. The mean pore radii were estimated for the gels prepared under di fferent conditions.