Perfluorotetradecanoic acid as an additive for friction reduction in full-film EHD contacts : the role of functional group, base oil polarity, additive concentration and contact pressure

Polajnar, Marko (avtor), Požar, Tomaž (avtor), Kalin, Mitjan (avtor)

Perfluorinated tetradecanoic acid was added as an additive to a base oil and tested under full film elastohydrodynamic (EHD) contact conditions between a steel ball and a steel disc. By varying key performance parameters, we aimed to assess the feasibility and limitations of perfluorinated carboxylic acids in reducing friction in lubricated contacts. The results demonstrate that the tested perfluorinated additive is effective in reducing friction when blended with a non-polar synthetic poly-alpha-olefin oil. However, no significant friction reduction was observed when the same additive was used in a slightly polar synthetic ester. The carboxylic acid functional group plays a crucial role in the observed friction-reducing effect. Adjusting the additive concentration further plays an important role in reducing friction. A concentration of at least 0.35 wt.% is required to achieve a notable friction reduction of approximately 10%. Increasing the concentration beyond this threshold continues to improve the friction-reducing effect. Conversely, increasing the contact pressure has a detrimental impact on friction reduction. The greatest reduction in friction—over 20% compared to the base oil—was achieved at the lowest contact pressure tested (0.69 GPa).

• Jezik: Angleški jezik
• Ključne besede: additives, EHD contact, base oil, concentration, pressure
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2025
• Št. strani: 12 str.
• Številčenje: Vol. 13, issue 6, art. 263
• PID: 20.500.12556/RUL-169952
• UDK: 539.92
• ISSN pri članku: 2075-4442
• DOI: 10.3390/lubricants13060263
• COBISS.SI-ID: 240516611
• Datum objave v RUL: 26.06.2025

Gradivo je del revije

• Naslov: Lubricants
• Skrajšan naslov: Lubricants
• Založnik: MDPI
• ISSN: 2075-4442
• COBISS.SI-ID: 12353563

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: aditivi, EHD kontakt, bazno olje, koncentracija, tlak

Projekti

• Financer: ARIS - Javna agencija za znanstvenoraziskovalno in inovacijsko dejavnost Republike Slovenije
• Številka projekta: P2-0231
• Naslov: Tribologija

• Financer: ARIS - Javna agencija za znanstvenoraziskovalno in inovacijsko dejavnost Republike Slovenije
• Številka projekta: J2-60050