Are Polyethylene and polypropylene made from crude oil?

NO. See Link. YES! From http://www.sustainablebusiness.com/index.cfm/go/news.feature/id/1363 Traditional foam "to-go" containers are made of polystyrene, while the clear plastic containers and bottles we see everywhere are made of polyethylene terephthalate (PET), polystyrene or polypropylene -- all petroleum-based plastic polymers. The ubiquitous paper coffee cup, and the paper take-out containers we see everywhere, also use a petroleum-based plastic coating to make them waterproof.

According to Green Seal, in 1997, 120 million pounds of foam polystyrene hinged containers were used in the U.S. food packaging industry and each American throws away an average of 100 polystyrene cups each year. Green Mountain Coffee Roasters recently estimated that last year Americans used 14.4 billion hot paper cups (placed end-to-end, this many cups would circle the world 55 times).

Not only do these plastic cups and take-out containers create garbage that ends up in the landfill for centuries to come (a polystyrene cup has an expected lifetime of over 500 years), they are made from non-renewable petrochemicals, and styrene, a key ingredient of polystyrene, is a suspected carcinogen and known hazardous substance.