Page 165 - Biodegradable Polyesters

6.2 Shape Memory Polymer Systems 143

O
OCN CH 2 NCO + H O(CH 2 ) 5 OH
m
MDI-1 PCL
SnOct ,
2
toluene, 110 °C
O O O
OCN CH 2 NH O (CH 2 ) 5 O (CH 2 ) 5 NH CH 2 NCO
m
PU-prepolymer
+
CH 3 CH 3 CH 3
H O CH 2 CH 2 OH or H OCH CH 2 O CH 2 CH 2 O CH CH 2 O H H OCH 2 CH 2 O CH CH 2 O CH 2 CH 2 OH
n
y x y x y x
PEG
Pluronic RPE Pluronic PE
O O O O O
CH 3 CH 3
HN CH 2 NH O (CH 2 ) 5 O (CH 2 ) 5 NH CH 2 NH O CH CH 2 O CH 2 CH 2 O CH CH 2 O
m
y x y
+ O CH 2 CH 2 O H
n
OCN CH 2 NCO
Linear polyurethane copolymer
MDI-2
O O O O O
CH 3 CH 3
HN CH 2 N O (CH 2 5 ) O (CH 2 ) 5 N H CH 2 N O CH CH 2 O CH 2 CH 2 O CH CH 2 O
m y x y
O O
NH NH Pluronic RPE
CH 3
OCH 2 CH 2 O CH CH 2 O CH 2 CH 2 O
x y x
CH 2
CH 2
Pluronic PE
NH NH
O O O O O O O
CH 3 CH 3
HN CH 2 N O (CH 2 ) 5 O (CH 2 ) 5 N CH 2 N O CH CH 2 O CH 2 CH 2 O CH CH 2 O
m H y x y
(a) Crosslinked polyurethane copolymer

(b)

Figure 6.6 Chemical pathway of the syn- different polyols under this trade name
thesis of multiblock linear and cross-linked (Czifrák, K., Karger-Kocsis, J., Daróczi, L.,
SM PU by incorporating high MW PCL soft Zsuga, M., Kéki, S. (2014) Poly(ε-caprolactone)
segment as switch phase (a) and demon- and Pluronic ® diol-containing segmented
stration of the shape memory effect set- polyurethanes for shape memory per-
∘
ting T = 80 C (b). Abbreviations – MDI: formance. Macromol. Chem. Phys. 215,
trans
®
methylene diphenyl diisocyanate, Pluronic : 1896–1907).