IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Glass Ball as Bullet Solubility System: Argon with Nitrogen, Oxygen, Carbon dioxide and Poly(ethylene terephalate) (PETP)
Components:
   (1) Argon with Nitrogen, Oxygen, Carbon dioxide; Ar, N2, O2, CO2; [7440-37-1, 7727-37-9, 7782-44-7, 124-38-9]  NIST Chemistry WebBook for detail
   (2) Poly(ethylene terephthalate) (PETP); ; [25038-59-9]  NIST Chemistry WebBook for detail
Original Measurements:
   K. Toi, J. Polym. Sci., Polym. Phys. Ed. 11, 1829-39 (1973).

 Variables:
   Temperature = 288 K - 315 K
   Pressure = 288 K - 315 K

 Prepared By:
   A.K. Bokarev

 Experimental Remarks:
   Henry's law is obeyed by O2, Ar, and N2, in all samples of PETP at pressure up to 1 atm. The deviations from Henry's law were observed for CO2. The dual mode sorption model equation was follow C=[1.89p/(1 + 0.45p)] + 0.38pa, where alpha is volume fraction of amorphous phase, for CO2 / PETP systems.

Heats of sorption for CO2 in PETP-75 at 70 cm Hg gas pressure was equal to –5.37 kcal/mol.



Experimental Data:   (Subscripts 1,2,3, ..., in column headings refer to components 1,2,3, ...)
   

The solubility coefficients S/cm3(STP) cm-3 atm-1 of gases in PETP-50 at 303 K
Chemical NameKeunen coefficient, S
N20.084
O20.092
Ar0.105
CO2 (a)1.353
 Notes:
   *  PETP-75.

 Method/Apparatus/Procedure:
   Manometric method was used for the measurement of solubility. The pressure changes due to sorption were measured with a cathetometer.

 Source and Purity of Materials:
   Four samples of commercial PETP (Diafoil, Mitsubishi Plastics Ltd.) were studied: one having amorphous structure (PETP-75) and three having the degree of crystallinity of 48.0 % (PETP-50, 75, and 100, where figures are the thickness of the samples). Completely amorphous PETP-75 had density 1.331 g/cc. Other samples had ρ = 1.400 g/cc. Commercial gases were used. CO2 was purified by the sublimation method by means of liquid nitrogen.

 Estimated Errors:
   Solubility: + 3%.