142 Advances in Polymer Science Editorial Board: A. Abe. A.-C ...

Poly(macromonomers), Homo- and Copolymerization 143
Table 1. Kinetic parameters of some macromonomers in radical polymerization as compared
with conventional monomers
Monomer MW
(g/mol)
Solvent/initiatora Temp.
(˚C)
k p
(l/mol) s
k t b
(l/mol s)
f Ref.
PSt-VB 23 4980 benz/AIBN 60 4 1.3´103c 2.6´103d 0.05c 0.03d 30
PSt-MA 24 400 benz/AIBN 60 18 8.4´103c 16.8´103d 0.2c 0.1d PMMA-VB 25
30
(isotactic) 2900 tol/AIBN 60 50 1.4´105b 0.28 32
(syndiotactic) 2720 tol/AIBN 60 4.7 1.3´103b 0.22 32
PEO-VB26
(m=1)
2260 benz/tBPO 20 40 1.8´103 0.15 34
water/AVA 20 1100 5.4´103 0.9 34
Styrene 104 – 60 176 7.2´107 0.7 35
– 20 60 3.5´107 – 35
MMA 100 – 60 515 2.6´107 – 35
a Solvent: benz=benzene, tol=toluene; initiator: AIBN=2,2'-azobisisobutyronitrile, tBPO=tert-butyl
peroxide, AVA=4,4'-azobis(4-cyanovaleric acid)
b The values are doubled from those in [30] and [32], where a convention of 2kt instead of kt in Eqs. (1)
and (2) was used in evaluation of kt c Assumed recombination for termination
d Assumed disproportionation for termination
Fig. 2a,b. Models of a propagation reaction of a poly(macromonomer) radical with a macromonomer;
b bimolecular termination between poly(macromonomer) radicals
while the diffusion-controlled termination between two multibranched radicals
is severely restricted, as expected from the steric requirements involved as illustrated
in Fig. 2.
As a result, by virtue of Eqs. (1) and (2), the macromonomers may polymerize
even more rapidly and to a higher degree of polymerization than the corre-