ISSN:
1042-7147
Keywords:
isotactic polystyrene
;
crystallization
;
transport properties
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Films of isotactic polystyrene (iPS) were quenched at different temperatures (0, 40, 100°C). 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 dynamic-mechanical 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 140°C, investigated with different techniques, such as DSC, FTIR and polarized optical microscopy, also reveals a different behavior. The kinetics of the crystallization become faster, the higher the quenching temperature. This result suggests the presence of domains that behave as nuclei of crystallization.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
Permalink
