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Some thermodynamic and kinetic properties of the system PETG‐CO 2 , and morphological characteristics of the CO 2 ‐blown PETG foams
Author(s) -
Paul Handa Y.,
Wong Betty,
Zhang Zhiyi,
Kumar Vipin,
Eddy Sharon,
Khemani Kishan
Publication year - 1999
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11396
Subject(s) - materials science , coalescence (physics) , solubility , blowing agent , atmospheric temperature range , diffusion , kinetic energy , thermodynamics , composite material , polyurethane , chemistry , physics , quantum mechanics , astrobiology
The solubility of CO 2 in PETG, a glycol‐modified PET, was measured at different temperatures and over a broad pressure range, and diffusion coefficients were derived at the corresponding conditions. The solubility of CO 2 is quits high. For example, almost 15 wt% CO 2 can be dissolved in PETG at 35°C and 6.0 MPa. Consequently, CO 2 is good blowing agent for PETG. Cellular foams in the density range of about 0.04 to 1.2 g/cm 3 and diameters in the range of about 10 to 150 µm were produced. The foam density and the cell size were found to depend on the foaming temperature and time, with larger cells obtained at higher temperatures or when the sample was foamed for a longer time. The foam density decreased with an increase in the foaming temperature to about 90°C, beyond which the density tended to increase slightly due to the cell collapse or coalescence. The density reduction also depended on the pressure at which the polymer was saturated with CO 2 ; the higher the saturating pressure at a given temperature, the greater the density reduction.