Relaxation processes in hybrid organic-inorganic polymer nanosystems polymerized in situ

Abstract

The relaxation processes of hybrid organic-inorganic polymer nanosystems (OIS) synthesized by joint polymerization of organic and inorganic components were studied using methods of differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and broadband dielectric relaxation spectroscopy (DRS). The organic component was a mixture of two products: high-molecular-weight macrodiisocyanate (MDI) with low reactivity and low-molecular-weight isocyanate-containing modifier poly(isocyanate) (PIC) with high reactivity. Sodium silicate (SS) was used as inorganic component. The structures of the OIS obtained were in the form of hybrids with covalently connected building blocks and interpenetrating networks: weakly cross-linked network MDI/SS and highly cross-linked network PIC/SS. Depending on the MDI/PIC ratio, one of the networks was prevailing and created a continuous structure with domains of second network.

Dielectric dispersion and relaxation studies of melt compounded poly(ethylene oxide)/silicon dioxide nanocomposites

“…Our survey of literature revealed that, so far the PEO and SiO 2 interactions and their effect on the polymer physico-chemical properties are characterized by rheological, differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), dynamical mechanical analysis (DMA), X-ray diffraction (XRD) scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements [1,[3][4][5][6][7]19]. Besides these experiments, the dielectric relaxation spectroscopy (DRS) is also a powerful tool for the study of polymer and nanofiller interactions and their effect on polymer dynamics in the PNC materials [20][21][22][23][24][25][26][27][28][29][30][31]. Further, the investigation on dielectric properties of such PNCs can provide the in-depth discussion of nanodielectrics, which is an emerging and fast-moving topic in electrical insulation for microelectronic devices.…”