Specialty Chemistry Forums > Citizen Chemist

Can a synthetic oil behave as a dry lubricant?

<< < (2/2)

xchcui:
Hi Enthalpy.
Thank you very much for your help.
Although your answer,as you said about the solid long paraffins,is just a hypothesis,your explanation is very helpful to
understand the issue.
In regards to the test,i guess i can use a cotton balls or
a piece of 100% cotton shirt instead of a candle wick(as i don't have separated candle wick).
This test sound as a simple and effective test,which
can solve my doubts.
Thanks again for your advice an your help. :)

Enthalpy:
Make any cotton very compact before lighting it, or it will burn in less than a second and you'll observe no effect by the paraffin. And keep your fingers away. Or use a piece of cloth, of paper - anything easily impregnated, usually a bunch of fibers. I used glass fibers for a huge wick.

==========

I can't resist exposing a similarity with rocket fuels...

"Simple" fuels, as were obtained long ago from refineries, were only separated by distillation. This did not suffice for airplanes and rockets, where the fuel can get really cold, and where it passes through injectors at the combustor. Airplanes needed to remove the water and the "paraffins", understood as dissolved long molecules that precipitate when the fuel is cold and clog the injectors.

Rockets added more requirements because the fuel gets hot in the engine's cooling jacket: lighter components that make bubbles and create badly cooled "hot spots" causing local thermal runaways were banned, as well as multiple bonds that polymerize at heat and have the same effect: boom.

So rockets asked the refineries for a fuel that is especially clean in these aspects. Someone called it wrongly "kerosene" despite the US Rp-1 is close to a Diesel fuel, not to jet fuel, and the Soviet Rg-1 is even denser but some 2s less efficient - more in the direction of boat fuel. Still today, most people repeat without checking that rocket Rp-1 is an aviation kerosene with narrower specs, which is wrong.

xchcui:
Thank you for your tips about the test options.
And while i am knowing now the chemistry of the long paraffins that are dissolved in shorter paraffin(as you explained before),it was easier to understand your explanation regarding the chemistry of the fuel and its suitability for different aircraft.
Besides that airplanes,rocket and explosions
are always interesting :)
Thanks,again,for the additional information.

Navigation

[0] Message Index

[*] Previous page

Go to full version