TY - JOUR
T1 - Alkyl-Cyclens as Effective Sulfur- and Phosphorus-Free Friction Modifiers for Boundary Lubrication
AU - Desanker, Michael
AU - He, Xingliang
AU - Lu, Jie
AU - Liu, Pinzhi
AU - Pickens, David B.
AU - Delferro, Massimiliano
AU - Marks, Tobin J.
AU - Chung, Yip Wah
AU - Wang, Q. Jane
N1 - Funding Information:
The authors gratefully acknowledge financial support from the US Department of Energy under contract DE-EE0006449. The NMR instrumentation at IMSERC was supported by the National Science Foundation under CHE-9871268, and GCMS instrumentation was supported by a donation from Pfizer. M.D. was supported by the Department of Defense (DoD) through the National Defense Science and Engineering Graduate Fellowship (NDSEG) Program. We thank Mr. Z. Liu for EHL film thickness calculation and Drs. A. Erdemir and A. Greco of Argonne National Laboratory, Drs. F. Lockwood and N. Ren of Ashland Corp., Dr. Y. He of Sinopec Corp., and Mr. B. Johnson for helpful discussions. We thank Mr. L. Kangmeng for help in disk preparation, Ms. Y. Du for help in SEM experiment, and Dr. A. Mouat for assistance with XRR data collection.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/3/15
Y1 - 2017/3/15
N2 - Modern automotive engines operate at higher power densities than ever before, driving a need for new lubricant additives capable of reducing friction and wear further than ever before while not poisoning the catalytic converter. Reported in this paper is a new class of molecular friction modifier (FM), represented by 1,4,7,10-tetradodecyl-1,4,7,10-tetraazacyclododecane (1a), designed to employ thermally stable, sulfur- and phosphorus-free alkyl-substituted nitrogen heterocycles with multiple nitrogen centers per molecule. The multiple nitrogen centers enable cooperative binding to a surface which provides strong surface adsorption and lubricant film durability in the boundary lubrication (BL) regime. A 1 wt % loading of the cyclen FM 1a in Group III base oil exhibits strong surface adsorption, leading to excellent reductions in friction (70%) and wear (95%) versus the pure Group III oil across a wide temperature range. The lubricant with the new FM additive also outperforms two commercially available noncyclic amine-based FMs and a fully formulated commercial 5W30 motor oil.
AB - Modern automotive engines operate at higher power densities than ever before, driving a need for new lubricant additives capable of reducing friction and wear further than ever before while not poisoning the catalytic converter. Reported in this paper is a new class of molecular friction modifier (FM), represented by 1,4,7,10-tetradodecyl-1,4,7,10-tetraazacyclododecane (1a), designed to employ thermally stable, sulfur- and phosphorus-free alkyl-substituted nitrogen heterocycles with multiple nitrogen centers per molecule. The multiple nitrogen centers enable cooperative binding to a surface which provides strong surface adsorption and lubricant film durability in the boundary lubrication (BL) regime. A 1 wt % loading of the cyclen FM 1a in Group III base oil exhibits strong surface adsorption, leading to excellent reductions in friction (70%) and wear (95%) versus the pure Group III oil across a wide temperature range. The lubricant with the new FM additive also outperforms two commercially available noncyclic amine-based FMs and a fully formulated commercial 5W30 motor oil.
KW - boundary lubrication
KW - friction modifier
KW - heterocyclic
KW - lubrication additive
KW - wear
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U2 - 10.1021/acsami.6b15608
DO - 10.1021/acsami.6b15608
M3 - Article
C2 - 28219241
AN - SCOPUS:85015404562
SN - 1944-8244
VL - 9
SP - 9118
EP - 9125
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
IS - 10
ER -