No abstract

Herein, a facile and effective dilution polymerization route was adopted to prepare microscale hierarchical PANI@BN nanohybrids with a surface textured similar to that of the aloe vera leaf. Synthesized samples were characterized by FTIR, XRD, FESEM, HRTEM, UV−visible absorption, and TGA/DTG. The hydrophobic nanohybrids with extremely rough surface offered a high barrier for moisture and corrosive environments. Potentiodynamic polarization measurement of PANI@BN/ PVA coated steel showed the large shifting in corrosion potential to the anodic region with respect to PANI/PVA. The corrosion inhibition efficiency (IE%) of PANI@ BN/PVA coating on mild steel in 3.5 wt % of NaCl, 1 M HCl, and 1 M H 2 SO 4 was calculated from the respective Tafel plots. The mechanistic investigation of anticorrosion performance was carried out through EIS analysis. The higher IE% of the synthesized nanohybrids with PVA coating formulation indicated that the superior anticorrosion performance on mild steel was due to synergetic effect between PANI and BN nanoparticles.

Chitosan/Boron nitride (BN) composites were prepared by solution method using CuSO4/glycine chelate complex as the catalysis with variable percentage of boron nitride loading. The dispersion of BN with the chitosan polymer was achieved with sonication at power of 120 W and frequency of 80 kHz. The chemical interactions of chitosan and BN were studied by Fourier transform infrared spectroscopy. The structure of chitosan and BN composites were investigated by XRD and TEM. It was observed that the BN were dispersed with chitosan matrix through intercalation. The quantitative identification of composites was investigated by Energy Dispersive X‐ray Spectroscopy and Selected Area Electron Diffraction. Thermal stabilities of chitosan/BN composites were studied by thermogravimetric analysis. It was found that, the thermal stability of the chitosan/BN composites was increased compare with virgin chitosan. The oxygen barrier properties of chitosan/BN composites were measured using gas permeameter. A substantial reduction in oxygen permeability was observed increasing boron nitride concentrations by which the synthesized composite materials may applicable in packaging industry.

Polyamide 6 (PA6)/clay nanocomposites were prepared using a single screw extruder with an ultrasonic die attachment. The die pressure and ultrasonic power consumption were measured at various clay concentrations. The structure and morphology of nanocomposites studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicated that the clay (Cloisite V R 30B) was exfoliated within PA6 matrix at all clay concentrations, while clays (Cloisite V R 15A and 93A) only intercalated. The complex viscosities of the nanocomposites were increased with clay loading and after ultrasonic treatment at lower amplitudes. The Young's modulus, stress and elongation at break, toughness and yield stress and strain of ultrasonically treated nanocomposites were significantly affected by the level of intensity of ultrasound. In addition to XRD, differential scanning calorimetry (DSC) and 15 N NMR techniques were used to investigate the structural changes in PA6/clay nanocomposites. The results indicated that the intercalated organoclay nanocomposites can induce generation of the cform crystal of PA6 and substantially affect the arrangement of molecules in the a-form crystal. It was found that the addition of clay in the PA6 matrix leads to a decrease of crystallinity. However, ultrasonic treatment of nanocomposites increased crystallinity. A substantial reduction in oxygen permeability was observed by increasing concentration of clay.