Novel aromatic mono- and di(phosphonate) or phosphonic acid monomers for use in dental composites were synthesized. Synthesis of monomer la involved three steps: (i) reaction of t-butyl alpha-bromomethacrylate (t-BuBMA) and Bisphenol A, (ii) conversion to diacid chloride derivative using thionyl chloride, (iii) reaction of diacid chloride with diethyl (2-hydroxyphenyl) phosphonate. Monomer 2a was synthesized from the reaction of 2chloromethacryloyl chloride and diethyl (2-hydroxyphenyl) phosphonate. Synthesis of monomer 3a involved reaction of glycidyl methacrylate (GMA) with diethyl (2-hydroxyphenyl) phosphonate. Hydrolysis of the phosphonate groups of monomers la and 2a with trimethylsilyl bromide (TMSBr) gave monomers 1b and 2b with phosphonic acid functionality, which is intended to improve binding ability of dental composites. The homopolymerization and copolymerization behaviors of the synthesized monomers with (Bis-GMA) were investigated using photo-differential scanning calorimetry at 40 degrees C with 2,2'-dimethoxy-2-phenyl acetophenone as photoinitiator. The interaction of the monomer 1b with hydroxyapatite (HAP) was investigated using Fourier transform infrared technique. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 97106, 2009