In this work, the thermal degradation characteristics of poly(isobornyl acrylate) (PIBA), and its copolymer with PMMA, P(MMA-co-IBA) were investigated via direct pyrolysis mass spectrometry. Thermal degradation behavior of poly(isobornyl methacrylate) (PIBMA) was also studied for a better understanding of thermal degradation mechanism of PIBA. For both PIBA and PIBMA, gamma-H transfer from the isobornyl ring to the carbonyl group was predominantly effective in thermal degradation. As a consequence of evolution of isoborylene, poly(acrylic acid) was produced. Trans-esterification reactions due to intermolecular interactions lead to evolution of H2O. Upon loses of CO2 and CO crosslinked units with higher thermal stabilities were generated. In case of P(MMA-co-IBA), intermolecular interactions between PIBA and PMMA chains were detected. Based on evolution of methanol, a trans-esterification reaction between the MMA and acrylic acid units generated by loss of isobornylene from PIBA chains was proposed. (C) 2013 Published by Elsevier B.V.