Modeling Thermogravimetry Analysis of Polyethylene Oxide Loaded with Fullerenes

Polyethylene oxide-fullerenes (PEO-C60), loaded by various amounts of C60, were obtained from homogenized solutions of water, toluene, and chloroform. Thermal degradation in nitrogen atmosphere at various heating rates ranging from 5 to 50 ^oC/min of PEO, C60 nanocomposites (PEO-C60NC), and molecular dispersions (PEO-C60MD) containing various weight fractions of C60 are reported. The research involves both the standard thermogram analysis and a detailed analysis of the derivatives and integrals of thermograms versus temperature. The coordinates of inflection points (inflection temperatures and inflection residual masses, degradation widths, and amplitudes), and areas of thermograms’ components are reported as a function of heating rate and C60 loading. The components of the thermograms’ spectrum have been deconvoluted by assuming that each main individual degradation process is described by a single sigmoid (or a single Lorentzian in the case of thermograms’ derivatives).

Data analysis is focused on the estimation of the weight fraction of the interphase in PEO-C60 nanocomposites and molecular dispersions and of the thickness of the interphase (assuming a uniform thickness of the interphase around C60). It was concluded that the thermal stability of PEO is improved by the addition of C60.