Study On Synthesis And Performance Of PAMPS PEM For Fuel Cell

Synthesis of proton exchange membrane (PEM) via cheap, environmentally friendly, predominant and fluorine-free 2-acrylamido-2-methyl propane sulfonic acid (AMPS) was put forward in order to improve the performance and reduce the cost of PEM full cell. Cross-link and composite technique was applied to improve the mechanical property, the methanol permeability of PAMPS. The cross-link and composite membranes have high mechanical property, low methanol permeability. Moreover, the membranes keep high proton conductivity, absorbent performance and water retentivity.Proton transfer in perflurinated sulfonated polymer electrolyte membranes (PFSI) was analyzed, the model of proton exchange channel is thought reasonable. Therefore, the design of nano-structures (5²5nm width) of numerous aqueous channels and hydrocarbon domains, and the novelty bi-continuous phase micro-emulsion polymerization technique were put forward. This results in the fabricated micro-emulsion PEM having higher proton conductivity as compared to other current commercial membranes, and the problem of loss water, wetting tardiness will be partially solved. The AMPS/MMA porous membrane has high proton conductivity, and the model of proton exchange channel is proved reasonable. At the same time, some conclusions had been summarized as following:(1) PAMPS has better chemical stability and therm-stability than general hydrocarbon, it can fit the environment of full cell. PAMPS is super absorbent polymer (SAP), and has high absorbent velocity. Initiator has important effect on molecular weight. 50 — 55D, 0.03wt % (NH₄)₂S₂O₈, the molecular weight of PAMPS is highest(1.92×10⁴). The more molecular weight high, the more absorbent performance good. PAMPS can saturate in 50⁶0 sec, enough for proton exchanging just 2⁵ sec, it can completely solve the problem of membrane saturating slow.(2) It was found that the PAMPS membrane has high proton conductivity(0.32 S · cm^-1), but high dimensional change and low mechanical property. After cross-link, the membranes have high water content(3wt%N,N'-Methylene-bis-acrylamide (MBA),110%) and high proton conductivity(3wt%MBA, 7.62×10²S · cm^-1) , but low dimensional change and high mechanical property (3wt%MBA, 23.6 MPa). 6% l,l'-Carbonyl- diimidazole (CDI)/bis (4-aminophenyl) sulfone (BAS) membrane has 110%, 24.5MPa, 6.21 × 10^-2 S ·cm^-1 in turn. The water retentivity of the tow kind membranes is better thanNafion.(3) Poly-2-acrylamido-2-methyl propane sulfonic acid-composite-polyvinyl alcohol (PVA) membranes has high water content, excellent mechanical property and water retentivity, low methanol permeability and little dimensional change. The cross-link of sulfonic ester and dehydration of PVA come into being in composite process, these can strengthen the mechanical property and dimension stability of membrane. With the increasing of the content of PAMPS, the proton conductivity goes up, and the methanol permeability is invariable. It was found that the composite membrane with 50% PAMPS showed mechanical property of 21.8Mpa, ionic conductivity( a ) of 5.4 * 10'2 S ? cm"1 and methanol permeability(P) of 3.2 * 10'8cm2 ? S"1. The composite membranes would be better than nafion membrane, if the ratio( P = o IP) is adopted to characterize the performance of a membrane.(4)When aqueous phase fraction is 18⁸0wt%, the phase behavior is bi-continuous modality for MMA/H2O(AMPS) micro-emulsion. The rate of SDS and OP-10 has important effect on emulsifier least content. As the rate of oil and water is 1:1 and the total content is 80 g, the optimal rate of SDS and OP-10 is 55% for SDS, and the total content of emulsifier is 10.5 g. With the increase of the content of AMPS, the emulsifier content goes up, but the extent is little. Initiator KMnO4-H2C2O2 and photo-initiator benzion is better than others. The width of channels is l⁵um, the smaller width was gotten in single-step UV-initiated polymerization process.(5) The bi-continuous modality of micro-emulsion kept well after polymerization,...