Effects of filler size on the curing mechanism of allyl-functionalized preceramic polymer

Abstract

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 °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 ∼ 116 kJ mol−1 for pure SMP-10 to 92.5, 88.5, and 85.8 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.

BibTeX

@article{2026_latheef_filler_size_preceramic,
  title     = {Effects of filler size on the curing mechanism of allyl-functionalized preceramic polymer},
  author    = {Latheef MA and Porobic Katnic S and LePage W and Keller MW and Ramsurn H},
  journal   = {Journal of Thermal Analysis and Calorimetry},
  year      = {2026},
  doi       = {10.1007/s10973-026-16041-x},
}

Vancouver

Latheef MA, Porobic Katnic S, LePage W, Keller MW, Ramsurn H. Effects of filler size on the curing mechanism of allyl-functionalized preceramic polymer. J. Therm. Anal. Calorim. 2026. doi:10.1007/s10973-026-16041-x

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This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature's AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s10973-026-16041-x