Vitrification Phenomena in Polysulfone/NMP/Water System

摘要

The vitrification line for the ternary system of polysulfone (PSf)/N-methyl-2-pyrrolidinone (NMP)/water was determined by differential scanning calorimeter (DSC) measurements with varying compositions.Pure PSf showed both #alpha#-and #beta#-tran-sition temperatures (T_G,#alpha#=187.5degC,T_g,#beta#=-21.4degC).The T_g,#alpha# of PSf decreased with increasing solvent concentration.The T_g,#alpha# of PSf decreased linearly with the addition of NMP in the concentration range of 70-90 wt % polymer.The vitrification line was indicated in the phase diagram for the ternary system of PSf/NMP/water at 15 and 60degC.A s the temperature is increased,a high polymer concentration was needed to reach the vitrification condition.The vitrification composition of the polymer in the binary system of PSf and NMP was 72.0 wt % at 15degC and 79.8 wt % at 60degC.We also found that the slope of the vitrification line changed with the temperature and that a small amount of water(10-20 wt %) can induce the vitrification of the polymer solution in the PSf/NMP/water system at 15deg .