Novel multifunctional initiators for polymerization of 2-oxazolines

Polymerization of 2-oxazolines was carried out using bifunctional and tetrafunctional initiators. Allyl-type dihalides and xylylene dihalides were used as bifunctional initiators. The allyl-type dihalides employed are 1,4-dibromo-2-butene and 3-iodo-2-(iodomethyl)-1-propene and the xylylene dihalides are p-xylylene diiodide and p-, m-, and o-xylylene dibromides. The degree of polymerization (DP) of the resulting polymer was very close to the feed ratio of the monomer to initiator. From a kinetic study, it was found that the polymerization using these bifunctional initiators for 2-oxazoline is a ''fast initiation-slow propagation system''. Electrophilic reactivities of allylic dibromide and allyl bromide were also evaluated by MO calculation to confirm the polymerization system. Tetrakis(bromomethyl)ethylene, an allylic tetrahalide, was used as a tetrafunctional initiator. The DP value of the polymer agreed well with the feed ratio. From super(1)H NMR and GPC analyses the polymer was of star-shaped structure.