摘要 : Hyperbranched polymer formation during step polymerization of AB(2) type monomer with different reactivity for the second B group is investigated to find the following universal characteristics that are invariant during the whole ... 展开 Hyperbranched polymer formation during step polymerization of AB(2) type monomer with different reactivity for the second B group is investigated to find the following universal characteristics that are invariant during the whole course of polymerization: (1) The degree of branching (DB) at large degree of polymerization (P) limit, DBP, and (2) the mean square radius of gyration for the unperturbed chains s20 having the same P. The value of DBP and the universal curve for s20 change with the reactivity ratio of two B groups; however, the universal power law s20P0.5 holds for large polymers, irrespective of the magnitude of reactivity ratio. The exponent, 0.5, is the same as that for the random branched polymers. Similarities and differences in comparison with random branched polymer formation are discussed. 收起