Study of nanoclay blends based on poly(ethylene terephthalate)/poly(ethylene naphthalene 2,6-dicarboxylate) prepared by reactive extrusion

Abstract

<jats:title>Abstract</jats:title> <jats:p>The success of processing compatible blends, based on poly(ethylene terephthalate) (PET)/poly(ethylene naphthalene 2,6-dicarboxylate) (PEN)/clay nanocomposites in one step by reactive melt extrusion is described. Untreated clay was first purified and functionalized “<jats:italic>in situ</jats:italic>” with a compound based on an organic peroxide/sulfur mixture and (tetramethylthiuram disulfide) as the activator for sulfur. The PET and PEN materials were first separately mixed in the molten state with functionalized clay. The PET/4 wt% clay and PEN/7.5 wt% clay compositions showed total exfoliation. These compositions, denoted nPET and nPEN, respectively, were used to prepare new nPET/nPEN nanoblends in the same mixing batch. The nPET/nPEN nanoblends were compared to neat PET/PEN blends. The blends and nanocomposites were characterized using various techniques. Microstructural and nanostructural properties were investigated. Fourier transform infrared spectroscopy (FTIR) results showed that the exfoliation of tetrahedral clay nanolayers is complete and the octahedral structure totally disappears. It was shown that total exfoliation, confirmed by wide angle X-ray scattering (WAXS) measurements, contributes to the enhancement of impact strength and tensile modulus. In addition, WAXS results indicated that all samples are amorphous. The differential scanning calorimetry (DSC) study indicated the occurrence of one glass transition temperature <jats:italic>T<jats:sub>g</jats:sub></jats:italic>, one crystallization temperature T<jats:sub>c</jats:sub> and one melting temperature T<jats:sub>m</jats:sub> for every composition. This was evidence that both PET/PEN and nPET/nPEN blends are compatible in the entire range of compositions. In addition, the nPET/nPEN blends showed lower T<jats:sub>c</jats:sub> and higher T<jats:sub>m</jats:sub> values than the corresponding neat PET/PEN blends. In conclusion, the results obtained indicate that nPET/nPEN blends are different from the pure ones in nanostructure and physical behavior.</jats:p>

The role of the compatibilizer on the microindentation hardness of iPP/PC blends

“…Moreover, polymer blends of recycled poly(ethylene terephthalate) (PET) with polyolefins (iPP or HDPE) have been also examined [29]. Recently [30] the microindentation or microhardness technique has been also very useful to elucidate the microstructure of multilayered systems based on blends of poly(ethylene terephthalate) (PET)/poly(ethylene naphthalene 2,6-dicarboxylate) (PEN)/clay nanocomposites. We found that the presence of nanoclay does not seem to have much influence on the microhardness values of the blends, which are lower than those predicted by the additivity law [16].…”

Study of Na-Montmorillonite–Polyamide Fiber/Polypropylene Hybrid Composite Prepared by Reactive Melt Mixing

“…This result can be explained by the reaction between the functionalizing agent used and Na-MMT which is a redox reaction that involves the octahedral crystalline portion. Thus, the organometallic components of Na-MMT octahedral structure react in the presence of cations supplied by decomposition of the peroxide and the accelerator [32]. According to Bouhelal et al [24], the technique of crosslinking by reactive extrusion that has been used in this present study gave rise to a partial or total exfoliation (4 wt% clay) with the absence of intercalated structure [25].…”