material, materiel

Material or material means the substance out of which something is made, physically or intellectually--
The new factory will be used to process the raw material into fiber for clothing.
He is looking for material for a new book.

Material also means pertaining to the physical or financial, instead of the spiritual or intellectual--
She thinks only of material gain, while he thinks about religion.

Material may also mean likely to make a difference in the outcome of a case; essential--
He has been summoned as a material witness.

Materiel or materiel ( from the French, also spelled matériel ), when used in English, means war supplies; arms, ammunition, and equipment--
The troops can walk; we need a plan to move the materiel.
Our army will confiscate all war materiel.

Now that you know that, you can say--
"We need oil to use as raw material for plastic, which we need for war materiel."