The Preparation And Charecterization Of Proton Exchange Membrane With Rubber As Substrate

Proton-exchange membrane fuel cells (PEMFCs) are considered to be a promising technology for clean and efficient power generation in the twenty-first century. Proton exchange membranes (PEMs) are the key components in a fuel cell system. The proton exchange membrane with high proton conductivity, low methanol permeability, perfect packing diffusion can be prepared successfully via an in-situ polymerization method. During the vulcanization process,-SO3H groups which functionalize rubber membranes with proton-exchange capability are introduced into the cross-linking structures of rubbers.Styrene sulfonic acid sodium (NaSS) is chosen as a kind of reaction packing, D25is taken as peroxide crosslinking agent. At the primal experiment, some kinds of rubber substrates are tried such as: chlorosulfonated polyethylene rubber (CSM) and butadieneacrylonitrile (NBR) and so on. According to the results of polarizing microscope (POM), Fourier transform infrared spectra (FT-IR) and so on, the reaction extent of NaSS is higher and homogeneous dispersion is much better in CSM comparing with the other rubber substrates, Fourier transform infrared spectra (FT-IR), XRD, scanning electron microscope (SEM) and transmission electron microscopy (TEM) are used to characterize the membranes in order to study the influence brought by the different amount of oxide initiators and NaSS on the proton conductivity, ion exchange capacity (IEC), grafting rate and methanol permeability.IEC value and proton conductivity of the CSM/NaSS membranes with8phr of D25were relatively higher than those of with14phr, which might indicate that increasing the amout of NaSS in CSM substrates can result in lower dispersion and grafting rate. When the amount of D25is8phr and14phr respectively, the proton conductivity of CSM/NaSS membranes with8and14phr of D25increase as increasing the amount of NaSS, reaching as high as2.53xl0-1S?cm-1.The membranes were prepared through the vulcanization process of rubber; the three-dimensional cross-linking structures of the membranes improve the dimensional stability, thermal stability, chemical stability and reduce methanol permeability as well. Comparing with the fluorine sulfonic acid proton exchange membrane which has been widely used recently, the advantages of this work may demonstrate is that this in-situ polymerization technique is a creative method for preparing the new proton exchange membranes with low cost, simplified production process, controllable sulfonated degree and excellent comprehensive performance.