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Author: Banerjee, Susanta × End date: 2023 × Start date: 2023 × WGL Institute: IPF ×

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    Synthesis and characterization of poly(1,2,3-triazole)s with inherent high sulfur content for optical applications
    (Hoboken, NJ : Wiley, 2023) Mazumder, Kajari; Komber, Hartmut; Bittrich, Eva; Voit, Brigitte; Banerjee, Susanta
    The synthesis of solution-processable sulfur-containing polytriazoles for optoelectronic applications is a relatively less explored domain in polymer research. The synthesis of novel bifunctional (DA) and trifunctional (TA) azido-monomers with inherent high sulfur content and of organo-soluble high refractive index poly(1,2,3-triazole)s using the azido-monomers via Cu(I) assisted click polymerization reactions are reported in this work. The azido-monomers were synthesized by the conversion of previously reported amine-functionalized compounds to azides using azidotrimethylsilane in a polar aprotic solvent. Dialkyne monomers were also synthesized and reacted with the azides to prepare a series of five linear and two hyperbranched poly(1,2,3-triazole)s. Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, differential scanning calorimetry and thermogravimetric analysis were used to characterize the synthesized polymers. It was also demonstrated that the use of the trifunctional azide in optimized conditions resulted in increased solubility of an otherwise insoluble linear poly(1,2,3-triazole). The optical characterization of the polymers was carried out on thin polymer films with thickness in the nanometer range, which were successfully prepared by spin-coating on silicon wafers. It was found that the increase in the sulfur and aromatic content in the polymer backbone successfully increased the refractive index of the polymers up to 1.743 at 589 nm.
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    Influence of different carbon nanotubes on the electrical and mechanical properties of melt mixed poly(ether sulfone)-multi walled carbon nanotube composites
    (Barking : Elsevier, 2012) Chakraborty, Sourav; Pionteck, Jürgen; Krause, Beate; Banerjee, Susanta; Voit, Brigitte
    Commercial Udel® poly(ether sulfone) (PSU) was filled with three different commercially available multiwalled carbon nanotubes (MWCNTs) by small scale melt mixing. The MWCNTs were as grown NC 7000 and two of its derivatives prepared by ball milling treatment. One of them was unmodified (NC 3150); the other was amino modified (NC 3152). The main difference beside the reactivity was the reduced aspect ratio of NC 3150 and NC 3152 caused by ball milling process. All PSU/MWCNT composites with similar filler content were prepared under fixed processing conditions and comparative analysis of their electrical and mechanical properties were performed and were correlated with their microstructure, characterized by optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). A non-uniform MWCNT dispersion was observed in all composites. The MWCNTs were present in form of agglomerates in the size of 10-60. μm whereas the deagglomerated part was homogeneously distributed in the PSU matrix. The differences in the agglomeration states correlate with the variations of properties between different PSU/MWCNT composites. The lowest electrical percolation threshold of 0.25-0.5. wt.% was observed for the shortened non-functionalized MWCNT composites and the highest for amine-modified MWCNT composites (ca. 1.5. wt.%). The tensile behavior of the three composites was only slightly altered with CNT loading as compared to the pure PSU. However, the elongation at break showed a reduction with MWCNT loading and the reduction was least for composite with best MWCNT dispersion. © 2012 Elsevier Ltd.