Commercial Uses of Propylene CH3 H polymerize HC-CH一CH3 C-C Ag cat. H H H H propylene oxide propylene polypropylene H+ HO JHO catalyst CH2-CH-CH3 CH3-CH-CH3 cat. CH3-C-CH3 OH OH OH 0 propylene glycol isopropyl alcohol acetone Copyright 2010 Pearson Prentice Hall,Inc. Chapter 7 11
Chapter 7 11 Commercial Uses of Propylene =>
Addition Polymers HCH「H CH3 H CH3 CH3 c间 polymerize C-C- -C -C-C-C- H propylene (monomer) polypropylene (polymer) H CI H H CI H CI polymerize H H H H LH HH H vinyl chloride poly(vinyl chloride) PVC,“vinyl' polymerize F tetrafluoroethylene poly(tetrafluoroethylene) PTFE,Teflon Copyright 2010 Pearson Prentice Hall,Inc. Chapter 7 12
Chapter 7 12 Addition Polymers
Physical Properties Low boiling points,increasing with mass. Branched alkenes have lower boiling points. Less dense than water. Slightly polar -Pi bond is polarizable,so instantaneous dipole- dipole interactions occur. -Alkyl groups are electron-donating toward the pi bond,so may have a small dipole moment
Physical Properties Low boiling points, increasing with mass. Branched alkenes have lower boiling points. Less dense than water. Slightly polar Pi bond is polarizable, so instantaneous dipoledipole interactions occur. Alkyl groups are electron-donating toward the pi bond, so may have a small dipole moment
Physical Properties Polarity Similar to alkanes,haloalkanes. H CH3 4=0.33D 4=0 cis-2-butene,.bp4°C tras-2-butene,.bp1°C H H u=1.7D H=0D b.p.=60°c b.p.=48°c
Physical Properties Similar to alkanes, haloalkanes. Cl C H C H Cl Cl C H C Cl H = 1.7 D b.p. = 60ºc = 0 D b.p. = 48ºc Polarity = 0.33 D cis-2-butene, bp 4 ° C C C H H 3 C H CH 3 = 0 trans-2-butene, bp 1 ° C C C H H H 3 C CH3
Stability of Alkenes Measured by heat of hydrogenation: Alkene H2->Alkane energy More heat released,higher energy alkene. difference 2.7 kcal (11 kJ) 30.3kcal(127kJ) 27.6kcal(115kJ) reaction coordinate
Stability of Alkenes Measured by heat of hydrogenation: Alkene + H2 Alkane + energy More heat released, higher energy alkene