Sorption of CO2, CH4 and Their Mixtures in Amorphous Poly(2,6-dimethyl-1,4-phenylene)oxide (PPO)

Valerio Loianno; Antonio Baldanza; Giuseppe Scherillo; Pellegrino Musto; Giuseppe Mensitieri

doi:10.3390/polym15051144

Sorption of CO₂, CH₄ and Their Mixtures in Amorphous Poly(2,6-dimethyl-1,4-phenylene)oxide (PPO)

Polymers (Basel). 2023 Feb 24;15(5):1144. doi: 10.3390/polym15051144.

Authors

Valerio Loianno¹, Antonio Baldanza¹, Giuseppe Scherillo¹, Pellegrino Musto², Giuseppe Mensitieri^{2

3}

Affiliations

¹ Department of Chemical, Materials and Production Engineering, University of Naples Federico II, Piazzale Tecchio 80, 80125 Naples, Italy.
² Institute for Polymers, Composites and Biomaterials, National Research Council of Italy, Via Campi Flegrei 34, 80078 Pozzuoli, Italy.
³ Reference Centre for Transformation Technology of Polymeric and Composite Materials, Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Piazzale Tecchio 80, 80125 Naples, Italy.

Abstract

Sorption of pure CO₂ and CH₄ and CO₂/CH₄ binary gas mixtures in amorphous glassy Poly(2,6-dimethyl-1,4-phenylene) oxide (PPO) at 35 °C up to 1000 Torr was investigated. Sorption experiments were carried out using an approach that combines barometry with FTIR spectroscopy in the transmission mode to quantify the sorption of pure and mixed gases in polymers. The pressure range was chosen to prevent any variation of the glassy polymer density. The solubility within the polymer of the CO₂ present in the gaseous binary mixtures was practically coincident with the solubility of pure gaseous CO₂, up to a total pressure of the gaseous mixtures equal to 1000 Torr and for CO₂ mole fractions of ~0.5 mol mol^-1 and ~0.3 mol mol^-1. The Non-Equilibrium Thermodynamics for Glassy Polymers (NET-GP) modelling approach has been applied to the Non-Random Hydrogen Bonding (NRHB) lattice fluid model to fit the solubility data of pure gases. We have assumed here that no specific interactions were occurring between the matrix and the absorbed gas. The same thermodynamic approach has been then used to predict the solubility of CO₂/CH₄ mixed gases in PPO, resulting in a deviation lower than 9.5% from the experimental results for CO₂ solubility.

Keywords: FTIR spectroscopy; NRHB; glassy polymers; mixed gas sorption; thermodynamic modelling.

Grants and funding

This research received no external funding.