Conductive polyurethane composites containing polyaniline-coated nano-silica

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Conductive polymers like polyaniline (PANI) are crucial for advanced materials.
• Developing efficient methods to incorporate PANI into polymer matrices is essential for enhancing material properties.
• Traditional methods often face challenges in achieving uniform dispersion and optimal property enhancement.

Purpose of the Study:

• To synthesize novel conductive polyurethane (PU)-PANI-silica nanocomposites.
• To investigate the impact of a silica-PANI core-shell nanoparticle structure on the properties of PU nanocomposites.
• To explore the potential of using 1.2-Aminopropyltriethoxysilane (APTS) as a coupling agent in this synthesis.

Main Methods:

• Synthesis of silica-polyaniline (PANI) core-shell nanoparticles using APTS as a coupling agent.
• Reaction of core-shell nanoparticles and PANI oligomers with isocyanates to form PU-PANI-silica nanocomposites.
• Characterization of electrical properties (surface resistance) and mechanical properties (tensile strength, elongation).

Main Results:

• The core-shell nanoparticle structure significantly enhanced electrical properties of the PU nanocomposites.
• A reduction in surface resistance to ~10(8) Ω/sq was observed with 5 wt.% PANI in the core-shell nanocomposite, a two-order decrease compared to non-core-shell structures.
• Tensile strength and elongation increased by 3.1 and 3.8 times, respectively, compared to neat PU.

Conclusions:

• The silica-PANI core-shell structure is highly effective in improving the electrical and mechanical performance of PU nanocomposites.
• The enhanced properties are attributed to increased contact probability among PANI moieties and improved chemical bonding between nanoparticles and the PU matrix.
• This approach offers a promising route for developing high-performance conductive polymer nanocomposites with minimal conductive filler loading.