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

• Published in: European polymer journal Vol. 67; pp. 128 - 142
• Main Authors: Bershtein, Vladimir, Fainleib, Alexander, Egorova, Larisa, Grigoryeva, Olga, Kirilenko, Demid, Konnikov, Semen, Ryzhov, Valery, Starostenko, Olga, Yakushev, Pavel, Yagovkina, Maria, Saiter, Jean-Marc
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2015
• Subjects: Crosslinking; Cyanate ester resins; Cyanates; Dynamics; Esters; Nanocomposites; Nanostructure; Networks; Polyhedral oligomeric silsesquioxane; Properties; Resins; Structure; Cyanate ester resins; Nanocomposites; Structure; Properties; Dynamics
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2015.03.022

[Display omitted] •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 0.01–10wt.% 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 (≪1wt.%), 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 10wt.%, 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.