can be characterized by mass spectrometry. This is the first case where an alkyl
zirconium cation intermediate in the homogeneous Ziegler–Natta polymerization
of ethylene has been detected directly.
1.8 Fabrication of Polymeric Structures Inside Microchannels
Using Fluid Flow
1.8.1 Polymerization on the Surface of Microchannels
Surface-initiated polymerization is an attractive method for fabrication of
microfluidic devices [244–247]. For example, Xu et al. reported surface-initiated
ATRP inside microchannels to produce flat gradient and patterned surfaces [248].
Fig. 37 Flow microreactor system for Ziegler–Natta polymerization
Table 9 Molecular weight and molecular weight distribution obtained in microreactor synthesis
Initiator
Temperature (
C)
Residence time (min)
M n
M w /M n
1
0
0.22
1,900
1.47
0
0.66
3,450
1.49
0
1.32
4,350
1.50
0
1.98
6,250
1.54
0
2.64
8,400
1.59
1
20
0.22
2,700
1.71
20
2.64
9,550
1.93
2
0
0.22
2,100
1.46
0
2.64
8,200
1.69
2
20
0.22
3,200
1.79
20
2.64
9,700
1.87
3
0
0.22
2,200
1.53
0
2.64
8,900
1.65
3
20
0.22
3,400
1.71
20
2.64
10,100
1.92
4
0
0.22
2,250
1.39
0
2.64
8,100
1.61
4
20
0.22
3,700
1.87
20
2.64
11,000
1.95
34
A. Nagaki and J.-i. Yoshida