Rubbery Soft Polymer Electrolyte Membrane with a Nanomatrix Channel Prepared from Natural Rubber

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Flexible fuel cells are crucial for a carbon-neutral society.
• Development of advanced polymer electrolyte membranes (PEMs) is essential for efficient fuel cell performance.
• Naturally derived materials offer sustainable alternatives for PEM fabrication.

Purpose of the Study:

• To prepare a rubbery soft PEM from deproteinized natural rubber (DPNR).
• To investigate the structure-property relationships of the novel DPNR-based PEM.
• To evaluate its potential for flexible fuel cell applications.

Main Methods:

• Graft-copolymerization of ethyl p-styrenesulfonate (SSEt) onto DPNR latex.
• Hydrolysis and cast film formation to create a nanomatrix channel.
• Characterization using 1H NMR, TEM, impedance analysis, and tensile testing.

Main Results:

• A DPNR-graft-poly(p-styrenesulfonic acid) (DPNR-graft-PSS) PEM was successfully synthesized.
• The PEM features a nanomatrix channel with well-dispersed hydrophobic rubber particles.
• Achieved a proton conductivity per unit equivalent (σ*) 1.4 times higher than Nafion117, with lower activation energy and higher tensile strength.

Conclusions:

• The DPNR-graft-PSS PEM demonstrates a promising nanomatrix channel structure.
• Its superior performance metrics make it suitable for advanced polymer electrolyte fuel cells.
• This naturally derived PEM offers a sustainable pathway for flexible energy devices.