Crystallization behavior of isotactic polystyrene quenched at different temperatures

✍ Scribed by E. Petrillo; G. Romano; R. Russo; V. Vittoria

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 403 KB
• Volume: 7
• Category: Article
• ISSN: 1042-7147
• DOI: 10.1002/(sici)1099-1581(199605)7:5/6<478::aid-pat508>3.0.co;2-y

✦ Synopsis

Films of isotactic polystyrene (ips) were quenched at different temperatures (0, 40, ZOOOC). Wide-angle X-ray diffractograms, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) show that the three samples are amorphous; slight differences were found in the density values and in the dynamicmechanical behavior. At variance, transport properties of methylene chloride vapor show that the higher the quenching temperature, the lower the sorption, at low vapor activity. The data are consistent with the presence, in the amorphous samples quenched at higher temperatures, of domains impermeable to vapors at low activity.

The crystallization of the three samples at Z4OoC, investigated with different techniques, such as DSC, FTIR and polarized optical microscopy, also reveals a different behavior. The kinetics of the c ystallization become faster, the higher the quenching temperature. This result suggests the presence of domains that behave as nuclei of crystallization.