Polypropylene (PP) plastic code 5
It is the second most important plastic after polyethylene.
It is a thermoplastic polymer that is rugged and unusually resistant to many chemical solvents, bases and acids.
It is used to make soup pots, margarine tubs, most bottle tops, waterproof clothing, carrier bags, ropes, non woven fibre products like the fluffy cottonwool type stuff used in tampons and nappies.
Does not biodegrade.
UK Collection Rates for recycling.Not generally collected for household recycling, although it has good potential.However, mixed plastic recycling is expected to be under way within five years. (please note this information is always changing. Updates will be posted here first so you may wish to double check.)
It is expected to net US$145 billion by 2019 and the sales of this material are forecast to grow at a rate of 5.8% per year until 2021.
In 2013, the global market for polypropylene was about 55 million metric tons. Wikkipedia.
Polypropylene is made from propylene. This in turn is made from propane.
Propane is derived from hydrocarbons
Hydrocarbon chains are refined by cracking and polymerising.
Very basically cracking breaks the existing chains and polymerisation is remixing them into something new.
Using high-temperature furnaces, propane is cracked into propylene,
Using a catalyst, a reactor and some heat propylene joins together to create a polymer called polypropylene.
Propane can be derived from Naptha ( which is distilled from crude oil)
90% of propylene is made from oil though that figure is rapidly changing as more is made from shale gas as a result of fracking.
“North America plans to build 6 new plants to to make “on purpose” propylene from propane “In the past the price of propylene and propane were so close in the U.S. that it wasn’t cost effective to dehydrogenate propane, but now with low cost propane from shale gas, it is. “
Polypropylene was discovered in 1951 by two chemists working for Phillips Petroleum Company.