Tribological performance of electrically conductive and self-lubricating polypropylene-ionic-liquid composites

Area of Science:

• Materials Science
• Polymer Chemistry
• Tribology

Background:

• Polypropylene (PP) composites require enhanced tribological and electrical properties for advanced applications.
• Achieving self-lubrication and electrical conductivity simultaneously in polymer matrices is challenging.

Purpose of the Study:

• To develop self-lubricating and electrically conductive polypropylene-based composites.
• To investigate the influence of carbon black (CB) and multi-walled carbon nanotubes (MWCNTs) with ionic liquid (IL) on material properties.
• To evaluate the tribological performance and identify application limits.

Main Methods:

• Preparation of PP composites by incorporating CB, MWCNTs, and an ionic liquid (trihexyltetradecylphosphonium docusate [P66614][DOC]).
• Characterization using high-resolution surface analysis (TEM, AFM) and spectroscopy (Raman, ATR-FTIR).
• Tribological testing to determine coefficients of friction (COF) under varying conditions.

Main Results:

• Reduced COF by up to 25% compared to neat PP.
• Achieved high electrical conductivity and self-lubrication.
• Identified contact pressure as a critical factor influencing COF.
• Revealed fundamental differences in filler-IL interactions.

Conclusions:

• The developed PP composites exhibit promising self-lubricating and conductive properties.
• These materials are suitable for applications in electrically loaded tribosystems, such as 3D-printed bearings.
• Understanding filler-IL interactions and tribological limits is key for optimizing performance.