Nanotech 2011 Vol. 1
Nanotech 2011 Vol. 1
Nanotechnology 2011: Advanced Materials, CNTs, Particles, Films and Composites

Composite Materials Chapter 5

Influence of Silica Nanoparticles on the Thermal Transitions and Structure of PHBA-PET Nanocomposites

Authors: F. Miranda, A. Acevedo

Affilation: University of Puerto Rico, Puerto Rico

Pages: 577 - 580

Keywords: nanocomposites, liquid crystals, silica

Abstract:
Composite films were produced by direct melt-blending of the polymer with up to 1.5 vol% loadings in a Thermo-Haake MiniLab2 twin-screw extruder. Thermal transitions were determined by differential scanning calorimetry and thermogravimetric analysis. Structure and morphology were analyzed by a combination of polarized optical microscopy, small-angle x-ray scattering (SAXS), and scanning electron microscopy. No significant changes were observed on the glass transition temperature, nevertheless the melting point showed a small tendency toward higher values at higher loadings. The nematic range decreased upon addition of particles, but was mostly unaffected by concentration. The maximum rate of degradation was displaced up to 30 ºC. A detrimental effect on the internal ordering of the polymer was also observed, as suggested by the reduction and eventual disappearance of the characteristic SAXS peak. Micrographs show a smooth film surface and straight fracture planes (i.e. no fibrils). Silica particles improved the thermal properties of the polymer, yet as the loading increase results suggest a reduction of the nematic range and order.

Influence of Silica Nanoparticles on the Thermal Transitions and Structure of PHBA-PET Nanocomposites

ISBN: 978-1-4398-7142-3
Pages: 882
Hardcopy: $199.95