Chem. J. Chinese Universities ›› 2024, Vol. 45 ›› Issue (8): 20240217.doi: 10.7503/cjcu20240217

• Polymer Chemistry • Previous Articles    

Preparation and Properties of Sulfonated Polystyrene/Sulfonated Poly(aryl ether ketone sulfone) Copolymer with Pendant Crosslinked Structure Composite Proton Exchange Membranes

CHENG Hailong(), HAN Kanghui, LI Ao, TAO Lujing, YI Feiyang, SUN Jiaojiao()   

  1. School of Materials Science and Engineering,Jilin Institute of Chemical Technology,Jilin 132022,China
  • Received:2024-04-29 Online:2024-08-10 Published:2024-06-25
  • Contact: CHENG Hailong, SUN Jiaojiao E-mail:chl_111@126.com;sjj@jlict.edu.cn
  • Supported by:
    the Research Foundation for Science and Technology of Jilin Province Department of Education, China(JJKH20220238KJ);the Natural Science Foundation of Jilin Province, China(YDZJ202301ZYTS299)

Abstract:

Balancing water absorption and dimensional stability, along with optimizing proton conduction and minimizing methanol permeation in proton exchange membranes(PEMs), has been a focal point in PEM research. In pursuit of this objective, a poly(aryl ether ketone sulfone) containing allyl group(PAEKS) was synthesized through the direct condensation polymerization. Subsequently, a series of sulfonated polystyrene/crosslinked sulfonated poly(aryl ether ketone sulfone)(cr-SPAEKS-xx stands for the content of sulfonic acid group) composite proton exchange membranes were prepared by grafting sulfonated polystyrene(SPS) and sodium styrene sulfonate onto the allyl groups in PAEKS through a radical reaction. The crosslinked composite membranes were characterized using 1H nuclear magnetic resonance(1H NMR) and Fourier transform infrared spectroscopy(FTIR). The scanning electronic microscopy(SEM) image showed that SPS and sodium styrene sulfonate distributed uniformly in the crosslinked composite membranes without any phase separation phenomenon. The crosslinked network structure enhanced the thermal stability, oxidation stability, and mechanical properties of the membranes. Simultaneously, the unique hydrophilic/hydrophobic phase separation structure and crosslinked network also effectively improve the dimensional stability and methanol resistance of the crosslinked composite membranes. At 80 ℃, the swelling rate of the cr-SPAEKS-120% membrane with the highest content of sulfonic acid group was only 20.1% with a water uptake of 63.5%. The highest methanol permeability coefficient of the crosslinked composite membrane was only 3.47×10‒7 cm2/s, significantly lower than that of Nafion117(23.80×10‒7 cm2/s). The hydrophilic/hydrophobic phase separation structure created by the unique chain structure also imparted excellent proton conductivity to the series of membranes. Specifically, the proton conductivity of cr-SPAEKS-120% achieved 0.043 S/cm and 0.113 S/cm at 20 and 80 ℃, respectively. As a result, these series of crosslinked composite membranes exhibited promising potential for applications in direct methanol fuel cells.

Key words: Sulfonated polystyrene, Sulfonated poly(aryl ether ketone sulfone) copolymer with pendant crosslinked structure, Dimensional stability, Methanol resistance, Crosslinked composite proton exchange membrane

CLC Number: 

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