A new concept for the synthesis of hyperbranched macromolecules involving the use of AB x macromonomers containing linear oligomeric units is introduced. This methodology is used for the preparation of a series of novel hyperbranched poly(ethylene glycol) derivatives containing linear poly(ethylene glycol) units of varying lengths and 3,5-dioxybenzoate branching units. An interesting feature of the hyperbranched poly(ethylene glycol) derivatives is their lack of crystallinity, which is used in the design of a new class of polyelectrolyte materials. The dependence of the ionic conductivity on temperature and the concentration of added lithium cations for these novel hyperbranched macromolecules is reported.

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The free-radical bulk polymerization of styrene initiated by dimethyl 2,2′-azobisisobutyrate at 70°C has been studied employing the techniques of Fourier transform near-infrared spectroscopy, electron spin resonance spectroscopy and gel permeation chromatography. The initiator efficiency (f) as a function of monomer conversion was estimated via an equation relating the instantaneous and the cumulative number average degrees of polymerization. The result was subsequently employed to calculate the conversion dependence of the termination rate coefficient (k t) from zero to the limiting conversion for different initiator concentrations. Over the course of the reaction, kt decreases by 5 orders of magnitude (10 7 -10 2 M -1 s -1 ). At conversion levels approaching the limiting value, kt shows a marked dependence on initiator concentration; higher initiator concentration shifts the kt vs conversion curves toward higher conversion levels. The reaction diffusion constant was found to decrease with increasing conversion in the high-conversion regime.