Chemistry Reference
In-Depth Information
(CH
2
)
5
CO
O
CH
2
CH
2
O
O
(CH
2
)
5
Bu
2
Sn
(CH
2
)
4
x
Bu
2
Sn
+
OCO
O
(CH
2
)
5
CO
OCH
2
CH
2
O
Cl-CO-(A)-COCl
(-Bu2SnCl
2
)
CO
(A)
CO
O
(CH
2
)
5
CO
O
(CH
2
)
4
CO
(CH
2
)
5
O
-(A)- = (CH
2
)
8
-
,
,
,
HC
CH
2
CH
CH
(CH
2
)
5
1)
+
O
CH
2
CH
2
CH
2
CH
2
O
CO
Bu
2
Sn
2)
+
Cl-CO-(A)-COCl
O
(CH
2
)
4
x
(-Bu2SnCl
2
)
CO
(A)
CO
O
(CH
2
)
5
CO
O(CH
2
)
4
O
CO
(CH
2
)
5
O
Formula 15.10
When bisphenol-A bis chloroformiate was used as reaction partner of the cyclic
macromers, carbonate groups were incorporated into the ''guest-host'' polyesters
[
51
].
This approach also enables syntheses of various multiblock copolyesters. Two
strategies were elaborated. First, a polymeric cyclic initiator was prepared, for
instance from oligo- or poly(ethylene glycol)s [
52
] or from poly(tetrahydrofuran
diol)s. The subsequent REP of a lactone (see Formula
15.10
, bottom) or of lactide
(see Formula
15.11
, top) yielded, in turn, multiblock poly(ether ester)s [
53
,
54
].
As demonstrated in Formula
15.11
, this strategy may involve spirocyclic Ge-
initiators [
54
]. Another variant of this strategy was realized in such a way that in
the first step acyclic amorphous copolymer was prepared from e-caprolactone and
