Dynamic Mechanical, Dielectrical, and Rheological Analysis of Polyethylene Terephthalate/Carbon Nanotube Nanocomposites Prepared by Melt Processing

Juris Bitenieks,Remo Merijs Meri,Janis Zicans,Krisjanis Buks

doi:10.1155/2020/5715463

Juris Bitenieks, Remo Merijs Meri + Show 2 more

Open Access

https://doi.org/10.1155/2020/5715463

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Abstract

The polyethylene terephthalate/carbon nanotube (PET/CNT) nanocomposites were prepared by melt mixing using a twin screw extruder. CNT content was varied up to 5 wt. %. Morphology as well as dynamic mechanical, calorimetric, and rheological properties of the PET/CNT nanocomposites was investigated. Morphological studies indicated that CNT bundles are regularly distributed within the polymer matrix creating a connected network structure which significantly affects the nanocomposite properties. Dynamic mechanical thermal analysis revealed increase in storage and loss modules of the investigated PET nanocomposites by increasing the content of CNTs. Differential scanning calorimetry results demonstrated increase in crystallinity of the investigated PET nanocomposites upon addition of the nanofiller. Rheological studies demonstrated that CNT addition up to 5 wt. % caused increment in complex viscosity and storage modulus. Rheological percolation threshold was observed to be 0.83 wt. % of CNT concentration, respectively.

Highlights

During the last decades, polymer nanocomposites have attracted attention as a class of advanced composite materials with a wide range of mechanical, electrical, and rheological properties making them useful in multifunctional applications
In our recent manuscript [16], we have demonstrated that addition of carbon nanotubes (CNTs) to the polyethylene terephthalate (PET) matrix via melt extrusion allows to obtain materials with a certain thermoelectric effect
The following measurement techniques were used to reveal the influence of CNT nanofiller on the performance of PET matrix nanocomposites: dynamic mechanical thermal analysis was performed to study the mechanical behavior over a broad temperature range, oscillatory rheometry measurements were applied to investigate rheological properties over a broad angular frequency range, broadband dielectric spectroscopy analysis was performed to reveal the dielectric behavior over a broad frequency range, scanning electron microscopy was used to reveal morphological characteristics, and differential scanning calorimetry analysis was used to determine the crystallization behavior

Summary

Introduction

Polymer nanocomposites have attracted attention as a class of advanced composite materials with a wide range of mechanical, electrical, and rheological properties making them useful in multifunctional applications. As demonstrated by a number of authors, rheological percolation threshold may be lower than electrical percolation threshold due to the fact that a less dense CNT network is required to sufficiently impede chain mobility related to the rheological percolation threshold [15] By considering these results, melt-manufactured PET nanocomposites have a potential to be applied as extruded, injection-molded, or compressionmolded products in smart applications simultaneously requiring high mechanical resistance, thermal stability, and electrical conductivity. Melt-manufactured PET nanocomposites have a potential to be applied as extruded, injection-molded, or compressionmolded products in smart applications simultaneously requiring high mechanical resistance, thermal stability, and electrical conductivity In this aspect, thermoelectric performance of composite materials has become increasingly attractive, especially in the light of increased energy demand, on the one hand, and reduced availability on energy supply due to diminishing amount of fossil resources, on the other hand. The following measurement techniques were used to reveal the influence of CNT nanofiller on the performance of PET matrix nanocomposites: dynamic mechanical thermal analysis was performed to study the mechanical behavior over a broad temperature range, oscillatory rheometry measurements were applied to investigate rheological properties over a broad angular frequency range, broadband dielectric spectroscopy analysis was performed to reveal the dielectric behavior over a broad frequency range, scanning electron microscopy was used to reveal morphological characteristics, and differential scanning calorimetry analysis was used to determine the crystallization behavior

Materials and Methods

Results and Discussion

Conclusions