Silicon carbide (SiC) particle incorporation is widely employed in polymer infiltration and pyrolysis processing to enhance densification and reduce shrinkage of preceramic polymer matrices. However, its influence on curing kinetics remains insufficiently understood. This study investigates how SiC filler size and loading affect the non-isothermal curing behavior of SMP-10, an allylhydridopolycarbosilane and a common precursor for SiC-based ceramic matrix composites. SMP-10 formulations containing micro- and nano-sized SiC particles at particle-to-polymer mass ratios of 0.1−0.3 were analyzed using differential scanning calorimetry at heating rates of 0.5–10 \(^\circ\) C min \(^{-1}\) . Activation energies were determined using Kissinger and Ozawa peak-based methods together with model-free isoconversional methods (Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO), and Starink). Master plot analysis was subsequently applied to identify dominant reaction mechanisms. Micro-SiC addition decreased the apparent activation energy compared with pure SMP-10. The average activation energy obtained from the KAS method decreased from \(\sim 116\,\mathrm {kJ\,mol^{-1}}\) for pure SMP-10 to 92.5, 88.5, and \(85.8\,\mathrm {kJ\,mol^{-1}}\) at micro-SiC loadings of 0.1, 0.2, and 0.3. In contrast, nano-SiC increased the apparent activation energy and introduced stronger conversion dependence, accompanied by systematic shifts of the curing exotherms toward higher temperatures. Master plot analysis indicated Avrami–Erofeev nucleation and growth kinetics for micro-filled systems, whereas nano-filled formulations exhibited reaction-order behavior at higher loadings. Despite these kinetic differences, the Gibbs free energies of activation remained within a relatively narrow range across all formulations. From a processing perspective, these findings provide guidance for selecting filler size and loading to tailor curing schedules in particle-modified SMP-10 systems used in PIP-derived SiC matrix composites.
