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Q & A: Polypropylene

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Most recent answer: 10/22/2007
Q:
Hello, What is polypropylene and how does it work to make gloves and other clothing warm? Thank You, Laura
- Laura Nicosia (age 50)
Dutchess Community College, Poughkeepsie, NY, USA
A:
Polypropylene is a kind of plastic. It is made of hydrogen and carbon atoms arranged in long chains. The prefix "prop" means the basic unit of these chains has three carbons in it (similar to propane and propene). The formula is (CH2 CH(CH3))-n where -n means this little unit is repeated over and over again in a long chain. The long chains make strong fibers which are useful in making synthetic insulation, thread, and rope.

Polypropylene thread is strong, lightweight, inexpensive, and resistant to chemical damage. The fibers can be fluffed up like cotton or polyester filling to make insulation. A big pile of disordered polypropylene fibers will trap air like any other insulator (a cotton ball works the same way). Trapping air prevents convection. The disordered array of fibers also prevents heat from being lost through radiation. Polypropylene fibers also are flexible, so they remain fluffy and soft so the gloves feel nice.

Tom

(published on 10/22/2007)

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