Scopul nostru este sprijinirea şi promovarea cercetării ştiinţifice şi facilitarea comunicării între cercetătorii români din întreaga lume.
Autori: Bercea M., Morariu S., Brunchi C.-E
Editorial: Romanian Academy, Publishing House of the Romanian Academy, Revue Roumaine de Chimie, 53(9), p.769-776, 2008.
The dynamic behaviour of polyacrylonitrile solution in dimethylformamide was investigated in presence of water as non-solvent. At low temperatures, the gelation becomes faster in presence of a small content of water (up to 3%). The sol-gel transition was investigated at C in function of water concentration through the evolution of the viscoelastic parameters as a function of time. The frequency sweep tests evidenced different behaviours in the sol (at 25C) and in the gel (at C) states. An increase of the water content (> 3%) determines a phase separation due to the decrease of the polymer-solvent miscibility.
Cuvinte cheie: polyacrylonitrile, sol-gel transition, viscoelastic parameters