there are two main kinds of polymers
Post on 30-Dec-2015
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There are two main kinds of polymers.
Type 1: Addition Polymers
Each small molecule adds to the end ofa growing chain. Polyethylene is an example
Type 2: Condensation Polymers
Monomer units come together with the eliminationof some small molecule (often water).Polyesters and nylons are examples
Condensation Polymers
Also called “Step-Growth Polymers”
Their synthesis does not involve a chainreaction.
Instead any two molecules can react atany time.
Instead any two molecules can react atany time.
Each end of the molecule reacts in turn forming dimers, trimers etc.
Nylons - Polyamides
HN
H
O
O
H
6-aminohexanoic acid
HN
H
O
O
Hzwitter ion
heat - H2O
N
H
N
O
H O
N
H O
N
HOn
Nylon 6 A polyamide
HN
H
HN
H
O
O
H O
O
H+
heat - H2O
O
N
O
N
H
N
H HO
O
N
H
N
H
O
n
Nylon 66
+H
N
H
HN
H
Cl
O
Cl
O
- HCl
O
N
H
N
H
O
O
N
H
N
H
O
n
Nylon 6-10
In the lab
O
N
O
N
H
N
H HO
O
N
H
N
H
O
O
N
O
N
H
N
H HO
O
N
H
N
H
O
O
N
O
N
H
N
H HO
O
N
H
N
H
O
O
N
O
N
H
N
H HO
O
N
H
N
H
O
O
N
O
N
H
N
H HO
O
N
H
N
H
O
Supramolecular Structure is Important
Hydrogen bonds hold the nylon chains together
O
O
H
O
O
HN N
H
H
H
H
+
heat - H2O
NN
H
HN
O
O
NN
H
H
O
OH
O
NN
H
HN
O
O
NN
H
H
O
OH
O
Kevlar - Helmets - Bullet Proof Vests
O
ON
H
H
H
O
ON
H
H
H
glycine zwitter ion
O
ON
H
O
NH
H
H
glycylglycine
O
ON
H
O
N
H
O
NH
H
H
glycylglycylglycine
O
ON
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
Nylon 2 - the simplest protein
O
OH3N
glycine alanine
O
OH3N
CH3
O
OH3N
O
H
serine
O
OH3N
S
H
cysteine
There are 20 principle amino acids
O
ON
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H
O
N
H R R R R R R
RR R R R R
Protein - 20 different R groups
Polyesters
O
O CH3
O
O
CH3
OOH
H+
dimethyl terephtalate ethyleneglycol
heat - CH3OH
O
O
O
O
O
O
O
O
O
O
O
O
Dacron
heat - CH3OH
ethyleneglycoldimethyl terephtalate
+ OOH
H
O
O CH3
O
O
CH3
OOH
H
O
H
+
glycerol
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
Cross linked
OHHO
+
O
ClCl
- HCl
phosgene
OO
O
O OO
O
O
O
Lexan n
Starch
-glucose
Polyether
DNA
DNA
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