anionic polymerization
B
+
M
B
+
M
B
B
M
+
M
What is the role of the
countercation?
(a)
(b)
anionic polymerization
examples
Na
+
Na
+
Radikalanion (grün)
CH2 CH
CH2 CH
C 6H 5
C 6H 5
2
CH2 CH
C 6H 5
+
CH CH2 CH2 CH
C 6H 5
C 6H 5
Dianion (rot)
living polymerization
living polymerization
cationic polymerization
R
+
M
R
M
(a)
R
+
M
RH M
(b)
Lewis-Acids:
MtXn +
HX
MtXn+1+
H
HX: H2O, HCl, HOR
poly(THF)
R3O BF4
+
O
R
+
O
R2O
BF4
R
O
R
O
O (CH2)4
O
ceiling temperature
Wachstum
R
O
+
kw
O
R
kd
Depolymerisation
Kgl
Pn
+
M
Pn+1
O (CH2)4
O