Reactive Dendronized Copolymer of Styryl Dendron and Maleic Anhydride: A Single Molecular Scaffold

Novel dendronized copolymers bearing reactive anhydride groups along the backbones are reported in this paper. They were synthesized through copolymerizations of styryl macromonomers bearing Fréchet-type dendrons of the first to the fourth generation and maleic anhydride (MAn) through conventional radical polymerization. The dendritic macromonomers were prepared by an accelerated convergent approach, i.e., a reaction of the dendritic bromide of lower generation with a styrene derivative bearing a 3,5-dihydroxybenzyl group. The dendronized copolymers with rather high molar masses were obtained under mild conditions, even for the fourth-generation dendritic monomer as determined by static light scattering (SLS). For example, the degree of copolymerization for the third-generation monomer reached 487. Owing to the reactivity of the anhydride, functional groups, which were buried by the grafted dendrons along the backbone, could be easily introduced as follows: (1) by the hydrolysis under acid conditions, the amphiphilic copolymers with a structure of dendron- alt -2COOH were prepared; (2) by reacting with alkyl primary amine, the copolymers with dendron- alt -linear alkyl chain were obtained in a quantitatively yields; (3) when reacted with a primary amino dendron of its generation different from the pendent dendron, a series of new dendronized copolymers with their side dendrons grafted in an alternative generation structure were produced. Therefore, the novel reactive dendronized copolymer presented herein can be a single molecular scaffold to be applied in nanomaterials and nanotechnologies of one dimension.