A boron-containing cyclohexanone formaldehyde resin (BCFR) was synthesized from cyclohexanone, formaldehyde, and boric acid. The effects of the boric acid concentration, solubility, molecular weight, and thermal properties on the product were investigated. Characterization of the BCFRs was done by NMR spectroscopy, gel permeation chromatography, and Fourier transform infrared-attenuated total reflectance spectroscopy. The thermal properties of the samples were determined with differential scanning calorimetry and thermogravimetric analysis. The study results demonstrate that the resin had higher heat-resistance properties than the commonly modified cyclohexanone formaldehyde resin. The obtained samples were also characterized morphologically by scanning electron microscopy. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013