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Comparative study of PLA nanocomposites reinforced with clay and silica nanofillers and their mixtures
Author(s) -
Kontou Evagelia,
Niaounakis Michael,
Georgiopoulos Panayiotis
Publication year - 2011
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.34234
Subject(s) - thermogravimetric analysis , materials science , interphase , nanocomposite , differential scanning calorimetry , composite material , montmorillonite , ultimate tensile strength , dynamic mechanical analysis , scanning electron microscope , micromechanics , polymer , chemical engineering , composite number , genetics , physics , engineering , biology , thermodynamics
This study compares the effects of two different types of nanosized fillers (silica and montmorillonite) at three different weight fractions as well their mixtures on the thermomechanical properties of polylactide (PLA). The role of aggregation and interphase was investigated in terms of several experimental techniques, including scanning electron microscopy, wide‐angle X‐ray scattering (WAXS), thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis (DMA), and tensile measurements. The experimental results clearly suggest that silica and montmorillonite have different reinforcing and toughening effects on PLA, while the combination of the two different nanofillers has a detrimental effect on the tensile properties of the material. Four micromechanics models describing the Young's modulus of the nanocomposites were used to study the different matrix–nanofiller interactions. The best fit of the experimental results was obtained with a model that assumes the presence of an interphase surrounding each nanoparticle. The increase of the nanofiller content above a certain amount was not accompanied by a corresponding increase of the interphase, because the total nanofiller surface area was counterbalanced by the creation of aggregates. It is postulated that the aggregation effect acts antagonistically to the interphase effect. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011