Page 62 - Biodegradable Polyesters

40 2 Functional (Bio)degradable Polyesters by Radical Ring-Opening Polymerization

Time 0 d 8 d 11 d 15 d

Weight %

PCL

20%

40%

Figure 2.6 Blends of amorphous and semicrystalline PCL with enhanced compostability
depending upon the amount of amorphous PCL in blends. (Reprinted from Ref. [21], Copy-
right (2010), with permission from Elsevier.)

3.0 O O
O H MMA, MDO
O O NN O
O O N Anisol, 80 °C, 4 h
H O n N
2.5 n m
O O CN O O O O O O O
O
2.0
Stress (MPa) 1.5 O q p O n O n NC O p O O 4 q

1.0

0.5

0.0
0 500 1000 1500 2000 2500 3000
Time (s)
Figure 2.7 Mechanical stress for a block step. A stable plateau after a reduction of
copolymer with semicrystalline PCL and the maximum force during the initial cycles
amorphous PCL–MMA blocks during 40 rep- showed no material flow and elastomeric
etitions of elongation to 200% with a rate of behavior. (Adapted from Ref. [69].)
−1
50 mm min , 2 s intermissions between each