A new organicinorganic hybrid material was prepared through reactive blending of hydrogenated carboxylated nitrile rubber (HXNBR) with epoxycyclohexyl polyhedral oligomeric silsesquioxanes (epoxycyclohexyl POSS). The structure of the composite was characterized by Fourier transform infrared spectroscopy (FTIR) and solid-state C-13 Nuclear Magnetic Resonance spectra (solid-state C-13-NMR). The differential scanning calorimetry (DSC) at different heating rates was conducted to investigate the curing kinetics. A single overall curing process by an nth-order function (1 - alpha)(n) was considered, and multiple-heating-rate models (Kissinger, FlynnWallOzawa, and Crane methods) and the single-heating-rate model were employed. The apparent activation energy (E-a) obtained showed dependence on the POSS content and the heating rate (beta). The overall reaction order n was practically constant and close to 1. The isoconversion FlynnWallOzawa method was also performed and fit well in the study. With the single-heating-rate model, the average E-a for the compound with a certain POSS content, 66.90-104.13 kJ/mol was greater than that obtained with Kissinger and Flynn-Wall-Ozawa methods. Furthermore, the calculated reaction rate (d alpha/dt) versus temperature curves fit with the experimental data. (c) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 3128-3126, 2012