Additives IV-Performance Additive

[MolaKule]

These additives fall into the Performance Additive classification.

See: http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=21;t=000023

First developed in 1953, this additive, called Polymethylacrylate or PMA, reduces viscosity change at low temperatures.

In the 1960's, Olefin CoPolymers or OCP's, were developed for the mineral oils of the day.

(Alkylated) Styrene esters are used for Automatic Transmission Fluids (ATF's), hydraulic fluids, and farm tractor fluids. Adding alkyl groups enhances its low temperature operation.

Hydrogentated Styrene-Diene CoPolymers were developed in the 1970's for the newly emerging class of synthetic fluids such as the di-esters, polyol esters, and PAO fluids. It is today one of the most widely used additives for the Group III fluids.

For gear oils, the synthetic hydrocarbons, PolyIsoButylenes or PIB's, fluids are used to enhace thermal and shear stability in gear lubes.

Since some of these same fluids are multifunctional, they also reduce friction and act as Friction Reduction agents, or FM's.

For some fully synthetic base oils, little of this additive is needed to stabilize the oil.

What is this additive and how does it function?

[ July 21, 2003, 07:23 PM: Message edited by: Patman ]

 

[Pablo]

Viscosity Index improvers.

 

[G-MAN]

VI improvers and (for mineral base oils) pour point depressants.

 

[MolaKule]

Well, all of you were correct, but G-Man was closest.

The PMA is a pour-point depressant for conventional oils, but also is a VII.

Although most of the wax is removed during refining of petroleum oils, enough remains to impede the flow of the oil when it separates at low temperatures as wax crystals. The PPD action is to block the normal crystallization of these waxes by "de-densifying" those crystals, i.e., PPD's reduce the density of the remaining wax when it attempts to form. Low molecular weight polymers accomplish this density reduction.

For other conventional oils, PAO's and esters are used as well to depress or "lower" the pour point.

How do VII's work? The simplest answer is that they cause the viscocsity of the total oil package to increase in viscosity as the temperature rises, and effect the oil very little at lower temperatures, thus preventing the oil from thinning out of its multiviscosity grade when temps rise.

In the molecular sense, these heavy-weight molecules coil at low temps and uncoil at high temps, thereby increasing the resistance to flow, which we define as an increase in viscosity. For conventional oils, one can start the formulation with a light viscosity oil, and make it perform as a higher viscosity oil at higher temperatures.

There are Viscosity Index Improvers which exhibit Dispersant properties as well, and are denoted as "Dispersant Viscosity Index Improvers." These are the Styrene-Based Polyesters, the Mixed Alkyl-Methacrylate-Vinyl Pyrrolidone's, and the Aminated Ethylene-Propylene VII's.

For synthetic oils, little if any of the VII is required, except for those oils who have a large viscosity grade span, such as 10W40, 10W50's, etc.

If you look at Redline's data, their single grade racing oils have a wide inherent viscosity range by just using the proper viscosity mix of PAO's and esters. However, since these racing oils have little detergency, they are only used for racing, and not for daily driver street cars.

[ June 05, 2003, 02:17 PM: Message edited by: MolaKule ]

 

[Robbie Alexander]

quote:

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Originally posted by MolaKule:
These additives fall into the Performance Additive classification.
--snip

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What additives would be:
1. Strictly Dino based if any
2. Strictly "SYNTHETIC"
3. Hybirds

Or are most either Hybirds or Syn's?

 

[MolaKule]

Here are texts on polymer chemistry for those interested:

P. J. Flory, "Principles of Polymer Chemistry", Cornell University Press (1953), Chapter VII, pp 266-316, and

"Macromolecules, an Introduction to Polymer Science", F. A. Bovey and F. H. Winslow, Editors, Academic Press (1979), pp 296-312.