TRANSPORT-PROPERTIES OF WATER IN GLASSY POLYCARBONATE FILMS - EFFECTSOF THE PROCESSING AND THICKNESS

Citation
A. Ruvolo et Mm. Murakami, TRANSPORT-PROPERTIES OF WATER IN GLASSY POLYCARBONATE FILMS - EFFECTSOF THE PROCESSING AND THICKNESS, Journal of macromolecular science. Physics, B37(5), 1998, pp. 627-643
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Polymer Sciences
ISSN journal
0022-2348
Volume
B37
Issue
5
Year of publication
1998
Pages
627 - 643
Database
ISI
SICI code
0022-2348(1998)B37:5<627:TOWIGP>2.0.ZU;2-E
Abstract
In this work, using water as an inert penetrant, it was possible to ob tain transport parameters without changing the original polymer struct ure, making possible a comparative analysis of how the methodologies o f preparation and film thickness can influence the structural organiza tion of the original polymer. A simultaneous analysis of transport and physical properties is very useful for this purpose. The water transp ort properties are of polycarbonate films, obtained via compression mo lding or solvent casting, controlling the cooling and the evaporation rates. From simultaneous analysis using wide-angle x-ray diffraction ( WAXD), differential scanning calorimetry (DSC), and apparent density m easurements, an analogy between the influence of the solvent evaporati on rate and the cooling rate on the polymer crystallization phenomena is proposed. The presence of ordered domains, dependent on the film th ickness, in the case of samples prepared by casting with low solvent e vaporation rates, was detected from the water transport properties at low vapor activity. At higher vapor activity, the water becomes permea ble through these ordered domains, and, from the point of view of the permeation experiments, the polymer matrix was homogeneous, independen t of the processing history and film thickness.