CER/POSS Nanocomposites

Abstract

The results of physical studies of the structure, dynamics, mechanical, and thermal properties of CER/epoxy-POSS nanocomposites based on CE monomers (DCBE, DCBA, 6F-DCBA) or oligomer (PT-30) published during the last decade are presented. The nanoparticle content in the nanocomposites varied from 0.01 wt.% to 10 wt.%, and their analysis was performed by TEM, EDXS, mid-IR, far-IR, XRD, SAXS, DSC, DMA, CRS, and TGA methods. The effective molecular dispersity of nanoparticles in the amorphous matrix and the most uniform POSS distribution in the composite nanovolumes were achieved only at their contents < 1 wt.%. This and the covalent “embedding” of POSS units into the matrix led to significant suppression of matrix (cycles) dynamics and to a significant improvement in the thermal and mechanical properties of the nanocomposites. The extremal dependencies of T_g on POSS content, with its increase from 240–250° to 280–300 ℃ at low POSS contents and the appearance of additional interfacial dynamics transition at 375 ℃, and the dynamic heterogeneity around T_g were found. The superiority of oligomer-based nanocomposites with T_g ~ 400 ℃, total thermal stability up to this temperature, regardless of the nature of the environment, and the increase of the modulus from ~ 2 GPa to ~ 4 GPa at 20 ℃ and from 0.1 GPa to 2 GPa at 300 ℃ are shown.