Mechanical and barrier properties of ternary nanocomposite films based on polycarbonate/amorphous polyamide blends modified with a nanoclay

Abstract

Ternary polycarbonate (PC)/amorphous polyamide-nanoclay (naPA) nanocomposite (PC/naPA) films were obtained by melt mixing and drawing, and the effects of the naPA content and the draw ratio (DR) on the structure, morphology and mechanical and barrier properties were studied. Despite the presence of nanoclay, the films exhibited a negligible roughness and the excellent optical properties of PC and amorphous polyamide (aPA). The dispersed naPA phase was pure and small, indicating compatibility. The naPA did not hinder the drawing ability of PC. At low DRs the dispersed phase was elongated and oriented along the machine direction (extrusion flow direction), but at high DRs, it fibrillated due to the higher non-isothermal elongational flow induced by drawing. The laminar structure of the nanoclay allowed the films to be reinforced both in the machine and the transverse directions. The oxygen permeability of PC was reduced by 42% in the nanocomposite with 25% of naPA, and dropped further with the DR, which is attributed to the increased tortuosity of the oxygen path induced by fibrillation.

Microstructure, thermal stability, and mechanical properties of modified polycarbonate with polyolefin and silica nanoparticles

“…Moreover, to find out whether the amorphous polyamide in the PC phase was mixed or reacted, FTIR spectrum did not show any new band. However, the band around 1630 cm −1 (Amide I), which is related to self‐association of amorphous polyamide chains through hydrogen bonding, appears slightly moved to higher wavenumbers . In another work, the incorporation of SEBS‐grafted‐maleic anhydride into PC/MMT NCs resulted in a decreasing trend of storage modulus ( E ′) .…”

“…[34] In PC/amorphous polyamide-nanoclay (naPA) NCs films, two T g were observed, which indicated the presence of two separate amorphous phases in the NCs. [35] Moreover, to find out whether the amorphous polyamide in the PC phase was mixed or reacted, FTIR spectrum did not show any new band. However, the band around 1630 cm À1 (Amide I), which is related to self-association of amorphous polyamide chains through hydrogen bonding, appears slightly moved to higher wavenumbers.…”

“…On the other hand, the rheological measurements provide the information about the microstructure of nanofillers in the melt, and the interphase interactions between NPs and the blends can be evaluated by Fourier transform infrared (FTIR) spectroscopy and phase morphology analysis . In PC/amorphous polyamide‐nanoclay (naPA) NCs films, two T g were observed, which indicated the presence of two separate amorphous phases in the NCs . Moreover, to find out whether the amorphous polyamide in the PC phase was mixed or reacted, FTIR spectrum did not show any new band.…”

“…However, the band around 1630 cm À1 (Amide I), which is related to self-association of amorphous polyamide chains through hydrogen bonding, appears slightly moved to higher wavenumbers. [35] In another work, the incorporation of SEBSgrafted-maleic anhydride into PC/MMT NCs resulted in a decreasing trend of storage modulus (E 0 ). [36] In PC/ABS/MWCNT, the rheological and transition electron microscopy results indicated that the MWCNT partitioning and state of dispersion of MWCNT were determined by the affinity between MWCNT and the blend components and MWCNT concentration.…”

Investigation of polyethylene‐grafted‐maleic anhydride presence as a compatibilizer on various properties of nanocomposite films based on polyethylene/ethylene vinyl alcohol/ nanoclay

“…One of the significant applications of packaging is a barrier against the permeation of oxygen into the package of oxygen sensitive products to prevent food spoilage . Application of plastic material with high gas and solvent barrier properties is found to be highly advantageous compared to metal and glass alternatives . Oxygen permeability, clarity, suitable mechanical properties, processability, recyclability, and low cost of production are among the main criteria for a suitable packing and especially for packing films—which can be produced in single‐ or multi‐layer types…”