Poly(ethylene terephthalate) nanocomposites with low loading (0.1–0.5 wt%) of graphene oxide (GO) have been prepared by usingin situpolymerization method. TEM study of nanocomposites morphology has shown uniform distribution of highly exfoliated graphene oxide nanoplatelets in PET matrix. Investigations of oxygen permeability of amorphous films of nanocomposites showed that the nanocomposites had better oxygen barrier properties than the neat PET. The improvement of oxygen permeability for PET nanocomposite films over the neat PET is approximately factors of 2–3.3. DSC study on the nonisothermal crystallization behaviors proves that GO acts as a nucleating agent to accelerate the crystallization of PET matrix. The evolution of the lamellar nanostructure of nanocomposite and neat PET was monitored by SAXS during nonisothermal crystallization from the melt. It was found that unfilled PET and nanocomposite with the highest concentration of GO (0.5 wt%) showed almost similar values of the long period (L=11.4 nm for neat PET andL=11.5 nm for PET/0.5GO).

This article describes the preparation process of two series of poly(trimethylene terephthalate) (PTT) nanocomposites with an addition of exfoliated graphite nanoplatelets with two different platelets’ size (50 and 500 μm). The influence of their size on processing, physicochemical properties, morphology and, most importantly, electrical conductivity and barrier properties of thin polymer films has been studied. It was clearly found that smaller platelets enabled to obtain conductive thin polymer films with a nanoplatelet content of 0.3‐0.5 wt.%. However, nanocomposite based on PTT with 0.5 wt% of EG with the flake size of 500 μm proved to be nonconductive. At the same time smaller EG platelets demonstrated a more uniform distribution in the PTT matrix, which was confirmed by means of scanning and transmission electron microscopies, thus giving the samples in question barrier properties with respect to CO2 and O2. Moreover, it has been shown that both nanofillers did not have a significant influence on the phase transition temperatures and on the long period. They caused however a slight decrease of crystallinity which is an evidence of an antinucleating character of those nanoplatelets in the PTT matrix. POLYM. ENG. SCI., 55:2222–2230, 2015. © 2015 Society of Plastics Engineers

This paper presents a comparative study on which type of platelets nanofi ller, organic or inorganic, will affect the properties of thermoplastic elastomer matrix in the stronger manner. Therefore, poly(trimethylene terephthalateblock-poly(tetramethylene oxide) copolymer (PTT-PTMO) based nanocomposites with 0.5 wt.% of clay (MMT), graphene nanoplatelets (GNP) and graphene oxide (GO) have been prepared by in situ polymerization. The structure of the nanocomposites was characterized by transmission electron microscopy (TEM) in order to present good dispersion without large aggregates. It was indicated that PTT-PTMO/GNP composite shows the highest crystallization temperature. Unlike the addition of GNP and GO, the introduction of MMT does not have great effect on the glass transition temperature of PTMO-rich soft phase. An addition of all three types of nanoplatelets in the nanocomposites caused the enhancement in tensile modulus and yield stress. Additionally, the cyclic tensile tests showed that prepared nanocomposites have values of permanent set slightly higher than neat PTT-PTMO.

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