Vitrification phenomena in polysulfone/NMP/water system

✍ Scribed by Je Young Kim; Young Duk Kim; Toshiyuki Kanamori; Hwan Kwang Lee; Ki-Jun Baik; Sung Chul Kim

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 166 KB
• Volume: 71
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19990118)71:3<431::aid-app9>3.0.co;2-2

✦ Synopsis

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 ␣and ␤-transition temperatures (T g,␣ ϭ 187.5°C, T g,␤ ϭ Ϫ21.4°C). The T g,␣ of PSf decreased with increasing solvent concentration. The T g,␣ 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 60°C. As 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 15°C and 79.8 wt % at 60°C. 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 15°C.