Predicting the effect of dissolved carbon dioxide on the glass transition temperature of poly(acrylic acid)

✍ Scribed by Gui-Ping Cao; Tao Liu; George W. Roberts

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 251 KB
• Volume: 115
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.31278

✦ Synopsis

Abstract

The morphology and size of poly(acrylic acid) (PAA) particles produced by precipitation polymerization in supercritical CO~2~ (scCO~2~) depends on the glass transition temperature (T~g~) of the polymer at reaction conditions. In this study, the use of the Sanchez–Lacombe equation of state (SL‐EOS), in conjunction with Chow's equation, to predict the effect of CO~2~ pressure on the T~g~ of PAA was evaluated. Characteristic parameters for PAA were determined by fitting density data. Characteristic parameters for CO~2~ were determined by fitting density data in the supercritical region. When the SL‐EOS was used in a purely predictive mode, with a binary interaction parameter (ψ) of 1, the solubility of CO~2~ in PAA was underestimated and T~g~ was overestimated, although the trend of T~g~ with CO~2~ pressure was captured. When was determined by fitting the SL‐EOS to the measured sorption of scCO~2~ in PAA, the calculated T~g~'s agreed very well with measured values. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010