Synthetic linear alkylates HF catalyzed appear more adapted to enhance the neutralization speed than natural alkylates. Additionnaly, a blend of synthetic and natural alkylates might be preferred.
The observations related to the soap content have been confirmed when studying the overbased phenate type additives, as the variations on the basic detergent are much less important than with the sulfonates. The overbased salicylate type additives can be compared to the phenates with respect to their surfactant properties, but data have shown some inconsistencies which limit the discussions on the observed varlations of the neutralization speed.
Apart from the neutralization ability characteristics of single detergents it has been shown that other parameters related to the formulation of marine lubricants can greatly influence the neutralization speed. For example, base oils and dispersants provide a neutralization speed variation of about 30% to more than 100%.
The general conclusron is that rt has been shown that selecting the "best" overbased detergent is not the best way to optimize the neutralization ability of a marine lubricant. The neutralization ability is a result of complex interactions between all the components that influence the surfactant properties and the global physico-chemical characteristics of the lubricant, which themselves govern the kinetics of the reaction between the acid and the base species. The formulation technique appears obviously to be the best way to find the compromise between all parameters, in order to optimize the neutralization ability.
6. AKNOWLEDGEMENTS
The author thanks very much Ronald J. Muir from CROMPTON CORPORATION for his valuable advice and for providing him specifically designed products. Some special thanks also to John D. Dennerlein who made possible this collaboration between CROMPTON CORPORATION and ELF-ANTAR France.
7. REFERENCES
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[2] Van Helden, A. K., CIMAC Report D-9 (1987)
[3] Davis, F. A., Moore, A. J. and Pridmore, S., CIMAC Report D-82 (1993)
[4] Roman, JP., Patent EP 000930503
[5] Roman, JP., Proceedings ofthe 22nd CIMAC International Congress on Combustion Engines, Copenhagen 18-21 May 1998, Vol.4, p 913
[6] Wu, R. C., Papadopoulos, D., Campbell, B., AIChE Journal, Vol. 45, No. 9 (September 1999), p 201
[7] Muir, R. J., CROMPTON CORPORATION, personal communication
