Gelation of poly(vinyl alcohol)/ethylene glycol solutions and properties of gels

✍ Scribed by Kazuo Yamaura; Hiroshi Kitahara; Tetsuya Tanigami

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 174 KB
• Volume: 64
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19970516)64:7<1283::aid-app6>3.0.co;2-f

✦ Synopsis

The melting temperature of the gels of the poly(vinyl alcohol) (PVA)/ethylene glycol (EG) system was measured. It was found that the temperature was independent of the thermal hysteresis. The apparent enthalpy of the fusion of the junction, DH, was 206 kJ/mol for a high molecular weight atactic PVA (HDP a-PVA), 172 kJ/ mol for a low molecular weight syndiotacticity-rich PVA (LDP s-PVA), and 238 kJ/mol for an HDP s-PVA. The gels obtained by chilling at temperatures over 80ЊC or by gradual cooling are considered to have larger microcrystals. The Young's modulus of the HDP a-PVA drawn films were highest among the samples tested. The maximum and mean Young's moduli of the HDP a-PVA films drawn 15 times the original length were 37 and 26 GPa, respectively.