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The diversification of environment congenial and conservative nanocomposites is prestigious because of increasing contamination in biota. Poly (D-glucosamine), a natural biopolymer is contemplated as a promising biodegradable polysaccharide for various applications mainly in food packaging, bone substitutes, and water filtration. The drawback of poly (D-glucosamine) is nadir mechanical strength and high hydrophilicity which could be amended by the introduction of graphene oxide (GO) nanoparticles (shows excellent load transfer). Homogeneous distribution and well dispersion of GO nanoparticles in poly (D-glucosamine) matrix have been concluded by SEM investigation. Inclusions of 1% GO into the biopolymer matrix results in enhancement of 83.21 MPa of tensile strength in contrary to pristine poly (D-glucosamine). It can be elucidated that increment in properties is due to the crosslinking reaction takes place between the amine and epoxide moieties that exist within poly (D-glucosamine) matrix and GO respectively. The thermal stability of nanocomposites has been increased on addition of nanofiller confirmed by TGA analysis. The resultant nanocomposites were examined for antimicrobial screening against various contagious bacterial strains for packaging applications. Electrochemical characteristics and capacitive investigation of the composites were also studied using cyclic voltammetry and impedance (EIS) respectively. EIS elucidated that the nanocomposite modified electrode exhibited good capacitance behaviour with the Bode phase angle (-45°) which proves the candidates have good capacitive properties. The electrocatalytic properties are found to be diffusion controlled in alkaline medium with good electrical conductivity with low resistance. It is envisioned that the resultant bionanocomposite has potential applications in packaging industry., Competing Interests: Declaration of Competing Interest Authors declare no conflict of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Impact-modified PBT/PTT blends and their nanocomposites with organically modified layered silicates (Cloisite 30B) were prepared via melt blending in a twin screw extruder to explore their rheological behaviour. The linear viscoelastic behaviour of nanocomposites was measured by parallel plate rheometer. ULDPE-g-GMA was used as an impact modifier for PBT and PTT polymeric matrix. It was observed from results that the storage modulus, loss modulus and complex viscosity of the nanocomposites increased with the incorporation of organoclay (OMMT). Addition of organoclay to polymer matrix increased the storage modulus of prepared nanocomposites and alters the shear thinning behaviour at low frequencies. Compositions having 5 wt % of organoclay showed high value of the storage modulus, loss modulus and complex viscosity. Moreover, storage modulus (G') and loss modulus (G") of impact-modified 25/75 PBT/PTT (NA3), 50/50 PBT/PTT (NB3) and 75/25 PBT/PTT blends based nanocomposites with 5 wt % organoclay loading increased more significantly at lower frequency range relative to other compositions. PBT/PTT blends based nanocomposites followed a strong shear thinning flow behaviour and decreased with increasing shear rates or frequency. This change in behaviour showed a solid like behaviour and it is related to the morphological changes. The complex viscosity of neat PBT, neat PTT and impact-modified PBT and PTT decreases with increasing frequency because of the shear thinning behaviour. [ABSTRACT FROM AUTHOR]

Elastomer toughened poly(butylene terephthalate) (PBT)/organoclay [Cloisite 30B, organo-montmorillonite (OMMT)] nanocomposites were prepared via melt blending using a micro-compounder. In this work, two types of impact modifiers, ultra low density polyethylene grafted glycidyl methacrylate (ULDPE-g-GMA, IM1) and ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA, IM2) were used, and a detailed comparison of the effect of both was made. With respect to the impact strength, 2 wt% of ULDPE-g-GMA produced a better result as compared to 2 wt% E-MA-GMA. Therefore, 2 wt% of ULDPE-g-GMA is considered as the optimized percentage for the preparation of nanocomposites. Being an impact modifier, ULDPE-g-GMA decreases the yield stress, tensile modulus and breaking strength of pure PBT. This issue was addressed in this paper by using organoclay, which may improve the tensile properties of PBT materials. The content of ULDPE-g-GMA was kept constant, whereas organoclay (OMMT) content was varied from 2 to 5 wt% in nanocomposites. The melting and crystallization behavior of pure PBT, impact modified PBT and its nanocomposites were studied by differential scanning calorimetry (DSC). Crystalline morphology was investigated using polarizing optical microscopy (POM) at 185°C, 195°C, and 205°C crystallization temperatures. The optimum increase in tensile modulus of the elastomer toughened PBT nanocomposites was seen with a 3 wt% addition of organoclay. [ABSTRACT FROM AUTHOR]