Influence of repetitions of the high-pressure hydrogen gas exposure on the internal damage quantity of high-density polyethylene evaluated by transmitted light digital image

A Review on Applicability, Limitations, and Improvements of Polymeric Materials in High-Pressure Hydrogen Gas Atmospheres

“…[62,66,70] During this diffusion-controlled gas desorption process, bubbles grow internally within the elastomer, which raises the stress concentration and results in irreversible damage, initiates cracks and propagates, and even develops into surface blisters, causing complete seal failure, when the stresses and strains at bubble walls surpass the tearing criteria of the polymer. [64,66,78,79] The possible phenomenology of this failure during decompression after exposure to a high-pressure gas is shown in Figure 3. If no cracks are initiated after the decompression, the formed bubbles are exterminated with the desorbing solute gas molecules.…”

“…However, it still can be catastrophic in extreme conditions. [79] Therefore, some researchers have tested elastomeric materials in high-pressure hydrogen gas conditions to gain more knowledge on the RGD phenomena and influencing parameters, as discussed below.…”

“…However, the dissolution is significantly less as the liner materials comprise high barrier and mechanical properties compared with the elastomeric materials. [79,99,100] Furthermore, the hydrogen gas molecules can penetrate through the polymer and accumulate at the interface of the liner and hosting composite Figure 5. Model of blister initiation; (a) right after decompression, (b) bubble formation by clustering supersaturated hydrogen molecules, and (c) blister initiation due to stress concentration caused by bubbles.…”

“…[101,103] The cavitation damage in liner materials as a result of RGD may also increase the probability of buckling collapse due to the degradation of the material properties. [79,99,100] Generally, HDPE is widely used as the liner material due to low gas permeability and low cost. However, PA grades are also widely used due to their low gas permeability properties.…”

“…[27,104] Similar to elastomers, in semicrystalline materials, the RGD is a diffusion-controlled phenomenon, therefore even after decompression cavitation may appear, and the cavitation is mainly dependent on the diffusivity and mechanical performance. [99] Ono et al [79] conducted tests to identify the internal damage initiation due to RGD in an HDPE grade exposed to 90 MPa of high-pressure hydrogen by analyzing transmitted light digital images. They revealed internal damage evolution quantitatively as a result of cyclic high-pressure exposure.…”