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)
