Preparation of new polymer nanocomposites based on chiral poly(amide-imide)/surface-modified ZnO nanoparticles containing 4,4′-methylene bis(3-chloro-2,6-diethylaniline) linkages via ultrasonication-assisted process

Studies on naphthalene and 1,2,3-triazole ring containing polyimides/zinc oxide nanocomposites

A novel diamine containing naphthalene and 1,2,3-triazole was synthesized by click reaction in the presence of Cu (I) catalyst. The synthesized diamine reacts with commercially available dianhydride and zinc oxide (ZnO) to form polyimide (PI) nanocomposites by a conventional two-step method. The structure of the monomers and polymers was characterized by Fourier transform infrared and proton nuclear magnetic resonance spectra. The morphology of the PI and PI/ZnO nanocomposite films was investigated by scanning electron microscopy and X-ray diffraction analysis. Meanwhile, due to the presence of a naphthalene side group, PI and PI/ZnO nanocomposite films possess high thermal stability, with a glass transition temperature over 259°C and a decomposition temperature with 5% weight loss over 501°C under nitrogen atmosphere. Also, low moisture absorption (0.28%) and good optical transparency were evident. The hybrid films possessed good mechanical properties, with a tensile strength of 112–127 MPa, an elongation at break of 10–15%, and a tensile modulus of 2.8–3.2 GPa.

Catalytically engineered reduced graphene oxide/ZnO hybrid nanocomposites for the adsorption, photoactivity and selective oil pick-up from aqueous media

Microwave mediated in situ growth of nanocrystalline ZnO on rGO nanosheets is achieved using APTMS as the crosslinking agent. The deposition of hydrophobic ZnO/Si@rGO on a simple cotton textile results in the selective adsorption of oil from aqueous media.

Organosoluble and optically active polyamides based on axially asymmetric 9,9′-spirobifluorene moieties

Optically active polyamides containing axially asymmetric 9,9′-spirobifluorene units in the main chain were synthesized for the first time by low-temperature solution polycondensation of ( R)-2,2′-bis(4-amino-2-trifluoromethylphenoxy)-9,9′-spirobifluorene with various diacyl chlorides. All these polymers were obtained in quantitative yields with inherent viscosities of 0.28–0.43 dL g−1. These polyamides were amorphous and readily soluble in many organic solvents such as N-methyl-2-pyrolidone, N, N-dimethylacetamide (DMAc), dimethyl sulfoxide, and tetrahydrofuran. The glass transition temperatures of these polyamides were recorded in the range of 199–261°C by differential scanning calorimetry, and the 10% weight loss temperatures were over 410°C both under nitrogen and in air atmospheres. The specific rotations of these chiral polyamides oscillated between 65.0° and 127.8° depending on the structures of the diacid chlorides. All the optically active polymers exhibited high chiral stability in solid state or in DMAc solvent at high temperature due to incorporation of chiral spirobifluorone unit in polymer backbones. The ultraviolet–visible and circular dichroism spectroscopic properties of these chiral polyamides in solutions were also studied.