Hydrogen sorption and desorption properties in rubbery polymer

• Published in: Materials chemistry and physics 2022-03, Vol.279, p.125745, Article 125745
• Main Authors: Jung, Jae Kap, Baek, Un Bong, Nahm, Seung Hoon, Chung, Ki Soo
• Format: Article
• Language: English
• Subjects: Adsorption; Chemisorption; Desorption; Diameters; Diffusion; Diffusion coefficient; Hydrogen; Hydrogen uptake; Polymers; Propylene; Rubber; Rubbery polymer; Sorption; Sorption equilibrium; Volumetric analysis
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2022.125745

We firstly characterized the sorption and desorption properties of hydrogen gas dissolved in rubbery polymer by utilizing a newly developed volumetric analysis technique. This method was applied to spherical-shaped sealing rubber, such as ethylene propylene diene monomer. The total sorption uptake (C∞), total desorbed content (C0), sorption diffusion coefficient (Ds) and desorption diffusion coefficient (Dd) of hydrogen in rubber are quantified as a function of diameter in both adsorption and desorption processes. No diameter dependence is observed for C∞ and C0, whereas Ds and Dd is diameter-dependent. The reversibility between C∞ and C0 observed in the process of adsorption and desorption implies the occurrence of physisorption rather than chemisorption by introducing hydrogen molecules. However, the difference between the Ds and Dd values may be ascribed to two different processes. Time to reach equilibrium in both sorption and desorption processes is found to be linearly proportional to the square of sample radius. •Characterized sorption and desorption properties of hydrogen gas dissolved in rubbery polymer.•Sorption uptake(C∞), desorbed content(C0), sorbed diffusivity(Ds) and desorbed diffusivity(Dd) are obtained.•No diameter dependence is observed for C∞ and C0, whereas Ds and Dd is diameter-dependent.•The reversibility between C∞ and C0 implies physisorption.•Equilibrium time could be predicted from linear relationship between time and squared radius.