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

Synthesis of Branched Polymers by Cationic Polymerization 53
ester functionality was retained after quenching the ester-Lewis acid complexes.
(35)
Following quantitative methylation of the w-tert-chloro site by trimethyl aluminum,
the methylated polyisobutylene methacrylate macromonomer was copolymerized
with MMA by Group Transfer Polymerization [87]. PMMA-g-PIB
graft copolymers with controlled MW and composition were obtained. The
structure and physical properties were determined by the [MMA]/[MA-PIB]
and [MMA]/[Initiator] ratios.
3.3.1.2
Synthesis Using a Functional Capping Agent
In this method, the polymerizable group is incorporated at the w-end of the
macromonomer by a reaction between a functionalized capping agent and the
living end of the polymer. To obtain well-defined macromonomers with one polymerizable
end group per chain, controlled MW and narrow MWD, the following
criteria should be fulfilled:
- living polymerization conditions;
- quantitative coupling of the quencher to the polymer end;
- formation of a stable bond;
- absence of side reaction of the functional group during the quenching process.
3.3.1.2.1
Poly(vinyl ethers)
Sodium salt of malonate carbanions are known to react quantitatively with the
living ends of poly(vinyl ether)s to give a stable carbon-carbon bond [45]. This
reaction was performed to end-functionalize living poly(vinyl ether)s with a vinyl
ether polymerizable end group using the functional malonate ion 36 [73, 89].
(36)
IBVE was polymerized with the HI/I 2 initiating system in CH 2Cl 2 at –15 °C.
After complete consumption of the monomer, five equivalents of the quenching
agent (with respect to the living end) were added. An instantaneous reaction was
evidenced by the precipitation of sodium iodide. Poly(IBVE) with controlled
MW (by the monomer to HI molar ratio) and narrow MWD was obtained as ev-