Are all carbon composites produced from oil?

[Armantium]

As I understand it, carbon composites are some combo of polymers and resins, which are derived from oil(black goo from the ground) as the main raw resource.

However, as this is carbon, couldn't such materials be produced also from other sources, like corpses, plants, etc? I mean, carbon is practically in all organic matter...Is the issue that oil is the most cost-effective?

 

[Borek]

Is the issue that oil is the most cost-effective?

Mostly. Still, there are polymers (which is a bit wider category than "carbon composites") that are made from plant matter. For example google for cellulose acetate and PLA.

 

[zbikraw]

Mostly. Still, there are polymers (which is a bit wider category than "carbon composites") that are made from plant matter. For example google for cellulose acetate and PLA.

Carbon composites are (or should be) designed materials in the sense they have to join permanently the filler or ceramics or polymer and the whole should demonstrate its superior properties. To meet these purposes C (mainly as C fiber) should fit into crystal or molecular structure of the remaining components. In practice most research concerns finding polymer wchich fits into C fiber.
To be useful in composite, C should be chemically homogeneous. This restriction eliminates all natural C sources expect diamonds (even graphite contain some impurities). Oil and natural gas are the only popular raw materials which gives access into high purity C on acceptable cost.
May be in the future someone designes C reffination from impure sources, but until now the most cost-effective way is burning this source and reduce resulting oxide into C.

 

[Jann Peter Simonsen]

oil(black goo from the ground) as the main raw resource.

However, as this is carbon,

Crude oil is far more complex than just being "composed of carbon" - it is a complex mixture of around 1000 different hydrocarbons and especially sulfurous-hydrocarbon compounds, as I understand it. The most "sludge like" components are tar and bitumen compounds and the more refined components are the light alkanes and alkenes (methane, ethane, methylene and acetylene (ethylene)).

Extracting the pure carbon from these substances probably in itself requires a good deal of energy and numerous complicated chemical and mechanical processes ("cracking" and fractionated destillation) and thereby a rather costly affair...but I imagine extracting pure carbon from other organic sources could be even more costly since raw organic substances are more "contaminated" with other elements and compounds.

Carbon fibre composites require a resin which is reinforced with a fibre - a bit like reinforced concrete, which is "held together" with strands of steel rod which give the overall concrete structure a stronger structure. The trick with carbon fibre composites is to find a reinforcing material which doesn't react chemically with the resin during the hardening process, as this would weaken the overall structure.

Carbon fibres are perfect for this, and especially the purer form graphite, which can be forced into a threadlike molecular crystal structure and thereby giving the fibre a high strength.
JPS

 

[zbikraw]

Oil is a mixture of compounds, not elements. So making C fibers from oil have to be a series of reactions decomposing these compounds to eliminate elements another than carbon. More important, these reactions and accompanying separation and purification stages should remove all components which would be difficult to separate from elemental C. The easiest and cheapest ways to achieve these goals starts from natural gas or petroleum, especially "sweet" brands.