The impact of ultra-low amounts of introduced reactive POSS nanoparticles on structure, dynamics and properties of densely cross-linked cyanate ester resins

• The strong impact of ultra-low amounts of POSS units on CER properties was found.
• POSS unit distribution in these composites was estimated via elemental Si nanoanalysis.
• Distinct composition–nanostructure–dynamics–properties correlations were established.
• Non-conventional thermal stability estimation before mass loss was made.
• Enhanced long-range action of constraining dynamics in these composites is supposed.

Thermostable nanocomposites based on densely cross-linked Cyanate Ester Resins (CER), derived from bisphenol E and doped by 0.01–10 wt.% epoxycyclohexyl-functionalized polyhedral oligomeric silsesquioxane (ECH-POSS), were synthesized and characterized in detail by means of TEM, SAXS, EDXS, FTIR, DSC, DMA, TGA, far-IR and creep rate spectroscopy techniques. It was revealed that ultra-low POSS contents (≪1 wt.%), covalently embedded into CER network, substantially changed its nanostructure and properties. This resulted in changing network dynamics; increasing glass transition temperatures by 20–50 °C; enhancing high temperature elastic and creep resistance properties, and increasing thermal stability under inert atmosphere at T < 400 °C. The effects being observed decreased, or even became zero or negative, while increasing POSS content, especially from 2 to 10 wt.%, due to arising the structural nanorod- or platelet-like formations and POSS-enriched nanodomains. At ultra-low POSS contents, the data obtained suggest basically molecular POSS dispersion, their quasi-periodic spatial distribution in the matrix, and not only chemical modifying CER network but also the possible manifestation of the enhanced long-range action of the “constrained dynamics” effect.

Figure optionsDownload as PowerPoint slide