Novel nanocornposites based on epoxy resin/epoxy-functionalized polydimethylsiloxane reinforced with POSS

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 (T-g), 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 FOSS aggregates exhibits lower T-g value and thermal stability in comparison with OEP-POSS nanocomposite which exhibits a nanoscale dispersion of the PUSS cages. The obtained T-g of OEP-POSS based nanocomposite increases with 31 degrees C in comparison with the unreinforced matrix. Moreover, this nanocomposite shows the highest storage modulus (E') and hardness. (C) 2015 Elsevier Ltd. All rights reserved.