• Tushar Jana

      Articles written in Bulletin of Materials Science

    • Functionalization of hydroxyl terminated polybutadiene with biologically active fluorescent molecule

      R Murali Sankar Subhadeep Saha K Seeni Meera Tushar Jana

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      A biologically active molecule, 2-chloro-4,6-bis(dimethylamino)-1,3,5-triazine (CBDT), has been covalently attached at the terminal carbon atoms of the hydroxyl terminated polybutadiene (HTPB) backbone. The modification of HTPB backbone by CBDT molecule does not affect the unique physico-chemical properties such as fluidity, hydroxyl value and microstructure of the parent HTPB. The formation of hydrogen bonding between the terminal hydroxyl groups and the nitrogen atoms of triazine moiety is the driving force for the terminal attachment chemistry. The functionalized HTPB (HTPB–CBDT) shows a strong fluorescence emission at 385 nm.

    • Synthesis of crosslinked poly(styrene-𝑐𝑜-divinylbenzene-𝑐𝑜-sulfopropyl methacrylate) nanoparticles by emulsion polymerization: Tuning the particle size and surface charge density

      Dhamodaran Arunbabu Mousumi Hazarika Somsankar Naik Tushar Jana

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      We have synthesized highly charged, crosslinked poly (styrene-𝑐𝑜-divinylbenzene-𝑐𝑜-sulfopropyl methacrylate) copolymer colloidal particles using emulsion polymerization. The effects of concentration of the emulsifier and the initiator on the particle size and the charge density of the colloidal particles are studied. Colloidal particle size is highly dependent upon the concentration of the emulsifier and the initiator. The colloidal particle diameter decreases with increasing concentration of the emulsifier and increases with increasing concentration of the initiator in the polymerization mixture. Number of particles, surface charge density and charges per particle are also functions of both the emulsifier and the initiator concentration. The surface charge density and the number of charges per sphere increase with increasing particle diameter. These copolymer colloid particles self assemble readily and diffract visible light. Polymer hydrogel imbibed with these colloids shows the light diffraction.

    • Functionalization of terminal carbon atoms of hydroxyl terminated polybutadiene by polyazido nitrogen rich molecules

      Rajavelu Murali Sankar Tapta Kanchan Roy Tushar Jana

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      We report a novel synthetic approach for the attachment of the polyazido nitrogen rich molecule on to the hydroxyl terminated polybutadiene (HTPB) backbone. The terminal carbon atoms of the HTPB are functionalized by attaching cyanuric chloride (CYC) covalently on the HTPB backbone. Further reaction of this modified HTPB with sodium azide yields polyazido nitrogen rich HTPB. The unique physico-chemical properties and the microstructure of the HTPB do not get affected upon modification. IR, gel permeable chromatography (GPC) and absorption spectroscopy studies prove that the polyazido nitrogen rich molecules are covalently attached at the terminal carbon atoms of the HTPB. The π electron delocalization owing to long butadiene chain, strong electron withdrawing effect of the triazine molecules are the major driving forces for the covalent attachment of the triazine at the terminal carbon atoms of the HTPB. The disruption of the intermolecular hydrogen bonding between the terminal hydroxyl groups of the HTPB chains and the presence of hydrogen bonding between the N atoms of the triazine ring with OH group of the HTPB are observed. Theoretical study also reveals the existence of the hydrogen bonding between the OH and N. Theoretical calculation shows that the detonation performance of the polyazido nitrogen rich HTPB are very promising.

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