Does anyone know for sure what plastic is made of?

Question

I've been asking people for years and nobody seems to know. I've heard a really good theory but I want to know if anyone really knows. Don't just say chemicals. Chemicals from what?

Answer 1

chemicals from petroleum mostly!  

Answer 2

Large part oil product, but they vary from item to item.  Look at the recycle triangle and note the number inside.  Each number denotes a different type of plastic, which in turn would be different chemical composition.    

Answer 3

I worked in plastics for 5 yrs and found that most of the basic types are a mix of powdered polymers and a special type of oil yechhhhh. so dont chew on any plastic.

Answer 4

I do this in my chem class!

You break down crude oil (or petroleum, whatev) into its parts.

Then, you take the ethene (in the industry, it is called ethylene), as monomers (molecules by themselves) and 'crack' them, usually via thermal cracking, where the ethylene is heated with a suitable catalyst (Zieger catalyst, I think) and the theylene goes from this CH2=CH2

to  n-CH2-CH2-n  where n is a number of other monomers, attached to each other, and can be thousands of links long.

Now you have polyethylene, which can be used to create plastics, or if changed from ethylene before cracking, it can be used to make Poly Vinyl Chloride (PVC) which is generally used in pipes.

Any questions? This is just a brief overview.