A series of hyperbranched polyacenaphthenequinones has been prepared by superelectrophilic aromatic substitution of (substituted) acenaphthenequinone and 1,3,5-tris-(4-phenoxybenzoyl)benzene via a facile A(2) + B-3 approach. Because of the strongly increased reactivity of the second A functionality, gelation was efficiently avoided during the polymerization. The structure of the resulting polymer was characterized by NMR spectroscopy and gel permeation chromatography. Further modification of the hyperbranched polyacenaphthenequinone was explored both on the acenaphthenequinone and aromatic moieties. Moreover, the polymer modified through sulfonation was investigated as a water-soluble acid catalyst for the degradation of biomass resources. (C) 2014 Wiley Periodicals, Inc.