Lubricant Additives

Ashless Antiwear and Extreme-Pressure Additives 233

succinic acid or anhydride have been identifi ed to be good fuel lubricity additives [84] (Structure M).
Alkyl hydrazide additives possessing two adjacent nitrogen atoms have also been claimed to exhibit
good antiwea r proper ties [85] (Str ucture N). Products of nitrogen heterocycles, such as ODZ (Tables
8.2 and 8.3 for performance evaluations), BZT, tolyltriazole (TTZ), alkyl succinhydrazide (SHDZ),
and borated hydroxypyridine (BHPD) (Structures O, P, Q, R, S, respectively), with pendant alkyl-
ates, amines or carboxylic acids have been found to be effective antiwear additives in both lubricants
and fuels [86–92]. Although triazoles are costly chemicals, they have unique geometric structures
that contribute to high surface fi lm–forming effi ciency.

RO(C 4 H 8 O)nCH 2 CH 2 CH 2 NH 2 (M)

STRUCTURE M

R 1 N

N

R 3

H

O

R 2

N

O

N

R 2

R 3

R 4

R 1 N

N

H

N

STRUCTURE N (AHDZ) STRUCTURE O (ODZ) STRUCTURE P (BZT)

TABLE 8.2

SAE 5W-20 Prototype Motor Oil Formulation

Component Formulation A (wt%)

Solvent neutral 100 22.8

Solvent neutral 150 60

Succinimide dispersant 7.5

Overbased calcium phenate detergent 2

Neutral calcium sulfonate detergent 0.5

Rust inhibitor 0.1

Antioxidant 0.5

Pour point depressant 0.1

OCP VI improver 5.5

Antiwear additivea 1

a In the case of no antiwear additive present in the formulation,

solvent neutral 100 is put in its place at 1.0 wt%.

TABLE 8.3

Four-Ball Wear Results

Compound Formulation Wear Scar Diameter (mm)

No antiwear additive A 0.73 (0.74)a

1.0 wt% ZDDP A 0.50 (0.51)

0.5 wt% ZDDP A 0.70 (0.67)

5-Heptadecenyl-1,3,4-oxadiazole A 0.38 (0.38)

5-Heptyl-1,3,4-oxadiazole A 0.54 (0.56)

5-Heptadecenyl-2,2-dimethyl-1,3,4-Oxadiazole A 0.7

5-Heptadecenyl-2-furfuryl-1,3,4-Oxadiazole A 0.38 (0.39)

a Duplicated runs.