Jung Jae-Kap, Kim Kyu-Tae, Chung Nak-Kwan, Baek Un-Bong, Nahm Seung-Hoon
Hydrogen Energy Materials Research Center, Korea Research Institute of Standards and Science, Daejeon 34113, Korea.
Electricity and Magnetism Group, Korea Research Institute of Standards and Science, Daejeon 34113, Korea.
Polymers (Basel). 2022 Apr 4;14(7):1468. doi: 10.3390/polym14071468.
We developed a method for characterizing permeation parameters in hydrogen sorption and desorption processes in polymers using the volumetric measurement technique. The technique was utilized for three polymers: nitrile butadiene rubber (NBR), ethylene propylene diene monomer (EPDM), and fluoroelastomer (FKM). The total uptake (C∞), total desorbed content (C0), diffusivity in sorption (D), and diffusivity in desorption (D) of hydrogen in the polymers were determined versus the sample diameter used in both processes. For all the polymers, the diameter dependence was not detected for C∞ and C0. The average C∞ and C0 at 5.75 MPa were 316 wt∙ppm and 291 wt∙ppm for NBR, 270 wt∙ppm and 279 wt∙ppm for EPDM, and 102 wt∙ppm and 93 wt∙ppm for FKM. The coincidence of C∞ and C0 in the sorption and desorption process indicated physisorption upon introducing hydrogen molecules into the polymers. The larger D in the desorption process than D could be attributed to an increased amorphous phase and volume swelling after decompression. The equilibrium time to reach the saturation of the hydrogen content in both processes was experimentally confirmed as proportional to the squared radius and consistent with the COMSOL simulation. This method could be used to predict the equilibrium time of the sorption time, depending on the radius of the polymers without any measurement.
我们开发了一种利用体积测量技术表征聚合物中氢吸附和解吸过程渗透参数的方法。该技术用于三种聚合物：丁腈橡胶（NBR）、三元乙丙橡胶（EPDM）和氟橡胶（FKM）。测定了聚合物中氢的总吸收量（C∞）、总解吸量（C0）、吸附扩散系数（D）和解吸扩散系数（D）与两个过程中使用的样品直径的关系。对于所有聚合物，未检测到C∞和C0与直径的相关性。在5.75MPa下，NBR的平均C∞和C0分别为316wt∙ppm和291wt∙ppm，EPDM为270wt∙ppm和279wt∙ppm，FKM为102wt∙ppm和93wt∙ppm。吸附和解吸过程中C∞和C0的重合表明在将氢分子引入聚合物时发生了物理吸附。解吸过程中的D大于吸附过程中的D，这可能归因于减压后非晶相增加和体积膨胀。通过实验证实，两个过程中达到氢含量饱和的平衡时间与半径的平方成正比，并且与COMSOL模拟结果一致。该方法可用于预测吸附时间的平衡时间，具体取决于聚合物的半径，而无需任何测量。
