Herein, we have fabricated a series of immiscible blend nanocomposites based on polycarbonate/polypropylene (PC/PP) by uniformly dispersing multiwall carbon nanotubes (MWCNTs) via a melt mixing technique. The effect of polypropylene-grafted maleic anhydride (PP-g-MA) as a compatibilizer has played a pivotal role in reducing the interfacial tension and thereby enhancing the attenuation performance of PC/PP blends. The substantial effect of compatibilization on the dispersion of MWCNTs has resulted in higher conductivity values of 0.33 S cm −1 , which is a major requirement for designing EM shields. Nevertheless, both the uncompatibilized and compatibilized blend nanocomposites have shown viscoelastic phase separation processes. The percolation networks of MWCNTs in compatibilized PC/PP blends were clearly observed using a high resolution transmission electron microscope. There was also a remarkable 5-fold decrease in the percolation threshold and 2.5 fold increase in total shielding effectiveness (54.78 dB) of compatibilized PC/PP blends when compared to that of immiscible PC/PP blends (22 dB).

The concept of conductive network structure in thermoset matrix without sacrificing the inherent mechanical properties of thermoset polymer (e.g., epoxy) is investigated here using "hairy" bentonite fillers. The latter were prepared through the in situ polymerization of aniline in the presence of 4-diphenylamine diazonium (DPA)-modified bentonite (B-DPA) resulting in a highly exfoliated bentonite-DPA/polyaniline (B-DPA/PANI). The nanocomposite filler was mixed with diglycidyl ether of bisphenol A (DGEBA), and the curing agent (4,4'-diaminodiphenylsulfone) (DDS) at high temperature in order to obtain nanocomposites through the conventional melt mixing technique. The role of B-DPA in the modification of the interface between epoxy and B-DPA/polyaniline (B-DPA/PANI) is investigated and compared with the filler B/PANI prepared without any diazonium modification of the bentonite. Synergistic improvement in dielectric properties and mechanical properties points to the fact that the DPA aryl groups from the diazonium precursor significantly modify the interface by acting as an efficient stress transfer medium. In DPA-containing nanocomposites, unique fibril formation was observed on the fracture surface. Moreover, dramatic improvement (210-220%) in fracture toughness of epoxy composite was obtained with B-DPA/PANI filler as compared to the weak improvement of 20-30% noted in the case of the B/PANI filler. This work shows that the DPA diazonium salt has an important effect on the improvement of the interfacial properties and adhesion of DGEBA and clay/PANI nanofillers.

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This perspective gives an overview of recent progress in the field of photocured polymer composites based on various forms of nanocelluloses, with a focus on cellulose nanofibrils. The manufacturing processes and performances of these nanocellulose composites are detailed, comprising solvent-assisted mixing processes, emulsification, coating and casting processes, preform impregnation, and 3D printing. Attention is also paid to life-cycle engineered approaches to improve their sustainability. These materials find applications in numerous domains, primarily as protective coatings but also as diffusion barrier composites and films for packaging and encapsulation of electronics, as composite hydrogels for biomedical applications, and as membranes for battery technologies.

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