Oxygen Barrier Properties and Melt Crystallization Behavior of Poly(ethylene terephthalate)/Graphene Oxide Nanocomposites

Abstract

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).

New functional nanocomposites based on poly(trimethylene 2,5-furanoate) and few layer graphene prepared by in situ polymerization

“…It is worth noting that PTF can be characterized by very low OTR values as compared to all these polymers, which are known for their good performances in packaging applications [64]. Previously, we found that the OTR value of PET equaled to 48.6±3.7 cm 3 /(m 2 ·24 h) [45]. However, Vannini et al [64], showed that OTR values measured at 23°C and 50% relative humidity were in the range of 0.0079-0.0472 cm 3 ·cm/(m 2 ·24 h·atm) depending on the aging time.…”

“…All specimens with a thickness of approximately 2 mm were placed on both sides of the Hot Disk sensor touching the sensor with plane surfaces. Oxygen permeability was measured using a MoconOx-Tran 2/10 instrument (23°C and 0% relative humidity (RH)) in accordance with ISO 15105-2 standard, while water vapor permeability was measured using a moisture analyzer (MAC 50, RADWAG, Poland) equipped with Sampler 2000, both using 5 cm 2 samples of examined polymer films accordingly to the procedure previously described in detail in [45,52]. All polymer samples were conditioned for 3h in the test chamber of OX-Tran apparatus in test parameters (23°C and 0% humidity rate RH).…”

“…Well-dispersed PTF/FLG nanocomposites were fabricated through a simple in situ polymerization method, preceded by an additional step of dispersing FLG (bio-PDO) using ultra-high speed stirrer and next an ultrasonicator, as described in the experimental section. The FLG contains some residual oxygencontaining functional groups (around 6% of oxygen) mostly from the edges and adsorbed ethanol residue and can be dispersed very well in liquid monomers (like ethylene or propylene glycol) at the level of individual flakes [40,45,52]. The dispersion state of FLG flakes in the PTF matrix was detected by scanning electron microscopy (SEM) and Figure 1a and 1b show typical SEM images of the cross sections of the PTF/FLG nanocomposites with 0.1 and 0.3 wt% loading, respectively.…”

“…It is especially wellseen in the polymer nanocomposites based on thermoplastic polyesters, like PET, PTT, PBT etc., which are engineering plastics with excellent processing characteristics and high strength and rigidity for a broad range of applications. Some studies on graphene nanoplatelets-polymer nanocomposites prepared by in situ polymerization, revealed significant improvements in electrical conductivity [40][41][42][43][44], thermal [45][46][47] and mechanical properties [42,44,46,47], and gas barrier properties [41,45]. However, Lotti et al [48] studied PEF nanocomposites containing 2.5 wt% of neat multi-walled carbon nanotubes (MWCNTs), or functionalized MWCNTs or graphene oxide (GO), that were in situ prepared by applying the melt polycondensation method.…”

Magnetic Properties of Poly(trimethylene terephthalate‐block‐Poly(tetramethylene oxide) Copolymer Nanocomposites Reinforced by Graphene Oxide–Fe3O4 Hybrid Nanoparticles

“…Using the most intense reflection (311), the average size of Fe 3 O 4 nanocrystals at GO surface was calculated to be ≈8.9 nm. In our earlier work, it was shown that the GO powder had characteristic diffraction peak at 2 θ ≈10° attributed to the (001) reflexion . The disappearance of this peak in X‐ray diffraction (XRD) pattern of GO–Fe 3 O 4 hybrid suggests that the layer stacking of the GO sheets has been destroyed by the loading of Fe 3 O 4 nanocrystals.…”