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

Synthesis of Branched Polymers by Cationic Polymerization 7
Fig. 1A–E. MWD of the products obtained from the reaction of living poly(IBVE) with divinyl
ether 1 in toluene at – 40 °C: DP arm =38, [living ends]=8.3 mmol l –1 , r=5.0: A living poly(IBVE):
[IBVE] 0 =0.38 mol l –1 , [HI] 0 =10 mmol l –1 , [ZnI 2 ] 0 =0.2 mmol l –1 , IBVE conversion=100%
in 45 min; B–E the products recovered after the reaction with 1. Reaction time
after addition of 1: (B) 10 min, (C) 30 min, (D) 1 h, (E) 18 h [star-shaped poly(IBVE)]. Reprinted
with permission from [3]. Copyright 1991 Am. Chem. Soc.
higher MW peak appeared indicating the simultaneous formation of star polymers.
Some low MW byproducts, assigned to homopolymer of 1 were also observed.
These progressively disappeared from the SEC chromatograms due to
their ability to react with the intermediate products of the reaction. As 1 was
consumed, the proportion of the intermediate product (block copolymer of
IBVE and 1) slowly decreased while the highest MW peak intensity increased
and its position shifted towards higher MW. After 18 h, the coupling agent was