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Organic-inorganic nanocomposites were designed by combining a commercial epoxy resin (diglycidyl ether of bisphenol A - DER) and a multi-thiol crosslinking agent with a “clickable” polyhedral oligomeric silsesquioxane (POSS) compound. 1-methylimidazole was employed as a catalyst to yield highly efficient thiol-Michael addition reaction materials. The equivalent ratio between epoxy: thiol was maintained 1:1 in all the formulations and therefore the homopolymerization reaction of epoxy resin is unlikely to occur. The synergistic effect of the thiol compound and mono-functionalized POSS bearing one epoxy/thiol reactive group on the curing process was investigated in detail. We assume that the mechanistic pathway of the thiol-epoxy click-reaction increases in complexity due to the introduction of reactive POSS in the system. The incorporation of mono-epoxy or mono-thiol POSS in the thiol–epoxy organic host leads to distinct thermo-mechanical behavior of the crosslinked networks due to the fact that the POSS compound will chemically interact in the click reaction.

This article reports the synthesis and characterization of several types of organic–inorganic nanocomposites based on epoxy resin/monoglycidylether-terminated poly(dimethylsiloxane) reinforced with 2, 5, or 10 wt% polyhedral oligomeric silsesquioxanes (POSS) bearing one glycidyl (1GE-POSS) or eight glycidyl(8GE-POSS) groups. The morphological features of the studied samples were established through atomic force microscopy, contact angle measurements, X-ray photoelectron spectroscopy, and scanning electron microscopy/energy-dispersive X-ray spectroscopy, and it was demonstrated that 8GE-POSS is well dispersed within the polymer matrix, while 1GE-POSS exhibits a high tendency to form aggregates. Differential scanning calorimetry (DSC) and Fourier transform infrared resonance (FTIR) measurements are used to follow the curing behavior and to study the polymerization kinetics of epoxy groups. As evidenced by DSC and FTIR results, the inclusion of 8GE-POSS within the polymer matrix leads to a lower epoxy polymerization rate of the resulted nanocomposites than those reinforced with 1GE-POSS. The dynamic mechanical analysis results revealed that the thermomechanical properties are gradually improved with increasing of 8GE-POSS content due to the higher cross-linking density.

The purpose of the present study is to develop novel nanocomposites based on diglycidylether of bisphenol A (DGEBA) combined with diglycidylether-terminated polydimethylsiloxane (DG-PDMS), reinforced with 10 wt.% (mono-/octa) epoxy POSS nanocages (MEP or OEP-POSS). DG-PDMS and POSS compounds were covalently incorporated into DGEBA resin via copolymerization of epoxy groups. The effect of both DG-PDMS and POSS nanoparticles on the curing reaction, glass transition temperature (Tg), thermal stability, hardness and morphology of DGEBA/DG-PDMS ± POSS nanocomposites were studied by DSC, FTIR, DMA, TGA, SEM/EDX, AFM and contact angle measurements. SEM/EDX and AFM results prove that OEP-POSS is well dispersed within DGEBA/DG-PDMS polymer matrix, while MEP-POSS forms large POSS aggregates. The thermo-mechanical properties of POSS based nanocomposites are also in good correlation with morphology features. MEP-POSS based nanocomposite with heterogeneous dispersion of POSS aggregates exhibits lower Tg value and thermal stability in comparison with OEP-POSS nanocomposite which exhibits a nanoscale dispersion of the POSS cages. The obtained Tg of OEP-POSS based nanocomposite increases with 31 °C in comparison with the unreinforced matrix. Moreover, this nanocomposite shows the highest storage modulus (E′) and hardness.

This investigation presents the synthesis of simultaneous interpenetrating polymer networks based on dimethacrylic/epoxy resins with or without polyhedral oligomeric silsesquioxane (POSS) via in situ polymerization. The curing behavior was studied using differential scanning calorimetry (DSC). The influence of the organic groups from the POSS cages on the curing kinetics of the IPNs was also studied by FT-IR spectrometry. The homogeneous phase structure of the cured IPN was proved by DMA tests. Additionally the integrity of the IPN was also demonstrated by thermal decomposition which occurs in one single step.

The aim of this study was to design novel binary and ternary copolymers based on methacrylate and/or epoxy monomers reinforced with 10 wt % mono-/octafunctional polyhedral oligomeric silsesquioxanes (POSS) compounds bearing one or eight epoxy or methacrylate moieties. The experimental parameters such as temperature and time of reaction, comonomer ratio and the incorporation of various types of POSS that strongly influences the curing behavior, polymerization kinetics, glass transition temperature (Tg), thermostability and morphological structure of the obtained copolymers were investigated through DSC, FTIR, DMA, TGA, and SEM techniques. The obtained results evidenced that the complex kinetic mechanisms of curing reactions for the binary and ternary copolymers ± POSS influence the thermomechanical and morphological properties of the materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42912.