As oil is used in an engine, it ages, creating oligomers. Is there a way that we can separate these oligomers without affecting the additives in the oil???
This is a little nebulous since an oligomer is basically a molecule made up of a limited number of any monomers, about a few dozen, is called an oligomer. this is different than a polymer which can have an unlimited number of monomers. A monomer is a molecule that can be linked to another identical monomer, approximately 2 to 36 of these linked together is called an oligomer. Polymers make the oils viscosity happen the longer they are the thicker it is. These polymers can be cut up while flowing through the engine and if cut small enough can be considered oligomers. But that is not the only form of oligomer there is in oil since you can have contamination oxidation additives that may cause reactions and a number of other things that can also create oligomers.
Now if someone has a list of oligomers that would be bad for an engine then there could be a study on how to eliminate them. If you can figure out how to eliminate one there is lots of money waiting for you from the oil or oil additive industry.
Also not all oligomers are bad for an engine. Engine oils have many different oligomers in it either as an additive, stabilizer, cleaner, etc. and also plain old sheared up oil.