Polymer–filler interactions in PET/CaCO3 nanocomposites: Chain ordering at the interface and physical properties

In this paper the formation of a partially ordered amorphous phase in PET/precipitated calcium carbonate (PCC) nanocomposites is highlighted and its effects on physical properties are discussed. PET/PCC nanocomposites are prepared by melt mixing, using an anhydride-modified PET (TPET) coupling agent synthesized on purpose. The effect of TPET/PCC interactions on PET amorphous phase conformation is revealed by solid state NMR and further investigated realizing a model of polymer/filler interface, by adsorbing TPET onto PCC. As a consequence of the interactions with the inorganic surface, the adsorbed polymer forms a trans-rich amorphous phase unable to crystallize. Addition of TPET also leads to an increase in the glass transition temperature and a reduction in the oxygen permeability of the nanocomposites.