The current report addresses the rheological and viscoelastic properties of poly (trimethylene terephthalate)/polyethylene blend system containing multiwall carbon nanotubes (MWCNTs). The alliance of MWCNT into the blend system raises both the modulus and the dynamic viscosity. The thermophysical properties of blend nanocomposites exhibit a lower threshold percolation particularly in comparison to nanocomposites PTT/MWCNT. The dynamic mechanical properties of nanocomposites were also enhanced by adding MWCNT and the higher storage modulus value of nanocomposites explains their reasonable load—bearing capacity by inserting MWCNT. Reinforcing efficiency factor, degree of entanglement density, coefficient of effectiveness, and volume of the constrained region of blend nanocomposites are studied and 90PTT/10PE/3CNT has shown maximum entanglement density value and reinforcement efficiency factor. Different theoretical models were used to predict the storage modulus of blend nanocomposites and among them, the Takayanagi model established fine concurrence with the experimental results.

A facile and economic method is developed for the fabrication of new lightweight materials with high electromagnetic interference (EMI) shielding performance, good mechanical properties and low electrical percolation threshold through melt mixing. Electrical properties, DC conductivity, EMI shielding performance and mechanical properties of poly(trimethylene terephthalate) (PTT)/multiwalled carbon nanotube (MWCNT) nanocomposites with varying filler loading of MWCNTs were investigated. High‐resolution transmission electron microscopy was used to determine the distribution of MWCNTs in the PTT matrix. The newly developed nanocomposites show excellent dielectric and EMI shielding properties. Theoretical electrical percolation threshold was achieved at 0.21 wt% loading of MWCNTs, due to the high aspect ratio and the three‐dimensional network formation of MWCNTs. Experimental DC conductivity values were compared with those of theoretical models such as the Voet, Bueche and Scarisbrick models, which showed good agreement. The PTT/3% MWCNT composite showed an EMI shielding value of ∼38 dB (99.99% attenuation) with a sample thickness of 2 mm. Power balance was used to determine the actual contribution of reflection, absorption and transmission loss to the total EMI shielding value. The nanocomposites showed good tensile and impact properties and the composite with 2% MWCNTs exhibited an improvement in tensile strength of as much as 96%. © 2018 Society of Chemical Industry

Theoretical analysis is carried out to predict the nature of selective localization of multi‐walled carbon nanotubes (MWCNTs) in poly(trimethylene terephthalate/polyethylene (PTT/PE) blends. In agreement with theoretical data experimental results clearly indicate that MWCNT prefers to get associated with PTT phase than with PE. Molecular interactions responsible for such selective localization of MWCNT to PTT component can be attributed to mutual and collective π–π interactions possible between the aromatic moieties present in PTT and MWCNT. In addition, the reinforcing effect of MWCNT in the PTT/PE system was determined using tensile analysis and the morphological features of blends and blend nanocomposites are studied using scanning electron microscope (SEM). Compared to the PTT/PE blend system MWCNT incorporated blend nanocomposites show better mechanical properties. The elongation at break of the blend system is seen to rise with increasing amount of PE content. Among various blend nanocomposites, we have investigated the nanocomposites with higher PTT content show higher tensile strength and Young's modulus. The blend nanocomposite with 90/10/1 composition shows 12% increment in Young's modulus and as much as 80% increment in tensile strength compared to 90/10 blend system which signifies the role MWCNT plays in the blend system.

EMI shielding materials and related research are of very relevance in this era of electronic gadgets. Here this report presents a binary thermoplastic blend nanocomposite system comprising poly‐(trimethylene terephthalate) and polyethene compatibilized with multiwalled carbon nanotubes, which are showing superior electromagnetic interference (EMI) shielding compared to similar systems. The blend composition with a 90/10 ratio of PTT/PE was showing the optimum properties when a MWCNT concentration of 1 wt% was incorporated. The compatibilization efficacy was analyzed and confirmed through scanning and tunneling electron microscopes. The MWCNTs are preferably localized in the PTT phase. The blend system provides an electrical percolation threshold of 0.19 wt% due to the double percolating effect of the blend system and MWCNT in the PTT phase. It was observed that the EMI shielding value shows a corresponding increase with MWCNT loadings. The most favorable value obtained for EMI shielding effectiveness was ~32 dB and it was with 3 wt% MWCNT of film thickness 2 mm in range of frequency 2–4 GHz. The PTT/PE/MWCNT system was not considered for EMI applications anywhere else. The theoretical support of the experimental data was examined for DC conductivity employing different models such as Voet, Bueche, and Scarisbrick and the actual contribution of reflection, absorption, transmission loss to the total EMI shielding was done with Power balance. The present work is a facile and cost‐effective method to fabricate lightweight and materials with high EMI shielding properties for mobile phones.

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