A rheometer coupled with a FTIR spectrometer under controlled atmosphere was successfully used to monitor in situ the synthesis of a preceramic polycarbosilane starting from two suitable monomers. This original hyper-branched polymer was obtained using the azide-alkyne cycloaddition activated by temperature. The device allowed for the following of the polymerization reaction by monitoring the intensity of several characteristic vibrational bands corresponding to the reagents (e.g. -N-3, C-H-alkyne) and the products (e.g. C-H-triazole). The impact of the surrounding atmosphere and the kinetic aspects of the reaction were investigated for the three studied temperatures, and an apparent activation energy of 73.3 kJ mol(-1) was calculated for the 1,3-dipolar polycycloaddition. (C) 2015 Elsevier Ltd. All rights reserved.