Effects of hydrogen-rich environment on the tensile properties of thermoplastics for liquid hydrogen service

Abstract Thermoplastic polymers can provide solutions for many liquid hydrogen storage and distribution applications, especially for weight sensitive applications. However, it remains unclear whether thermoplastics can operate consistently at cryogenic temperatures particularly after long term exposure to hydrogen-rich environments. This study measured the mechanical behaviours of three thermoplastics at room and cryogenic temperatures (77 K and 20 K), and compared the results of hydrogen charged and uncharged samples. All materials showed increased ultimate tensile strengths and reduced ductility at cryogenic temperatures compared to results at room temperature. The amount of hydrogen absorbed may have a positive correlation to their molecular weight. However, the method of hydrogen charging applied in this work appear to have marginal effects on the thermoplastics. Further chemical examinations is in progress to reinforce.