Interactions between Nafion resin and protonated dodecylamine modified montmorillonite: a solid state NMR study

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Perfluorosulfonylfluoride copolymer resin (Nafion) is a key material in various applications.
• Layered montmorillonite (MMT) is a common filler for polymer composites.
• Improving the thermal stability of Nafion-based materials is crucial for enhanced performance.

Purpose of the Study:

• To prepare and characterize Nafion-MMT nanocomposites.
• To investigate the effect of dodecylamine modification on MMT and Nafion.
• To understand the interactions responsible for improved thermal stability.

Main Methods:

• Sol-gel intercalation method for nanocomposite preparation.
• Characterization using FT-IR, elemental analysis, XRD, and various solid-state NMR techniques (19F MAS, 19F NMR relaxation, 29Si MAS, 1H MAS, 1H-13C CPMAS, 1H-13C HETCOR 2D NMR).

Main Results:

• Dodecylamine modification did not significantly alter the MMT lattice structure.
• Protonated dodecylamine intercalated into MMT interlayers, while Nafion did not.
• Strong electrostatic interactions were observed between dodecylamine and Nafion.
• Moderate improvement in Nafion's thermal stability was achieved.

Conclusions:

• The improved thermal stability of Nafion-dodecylamine-MMT nanocomposites is attributed to electrostatic interactions between dodecylamine and Nafion.
• The study highlights the potential of modified MMT as a reinforcing agent for Nafion.
• The findings contribute to the development of advanced polymer nanocomposites with enhanced thermal properties.