Fluoroalkenes polymerize more exothermically than normal alkenes. Unsaturated fluorocarbons have a driving force towards sp hybridization due to the electronegative fluorine atoms seeking a greater share of bonding electrons with reduced s character in orbitals. The most famous member of this class is tetrafluoroethylene, which is used to manufacture polytetrafluoroethylene (PTFE), better known under the trade name Teflon.