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Nitroxide-mediated polymerization was successfully employed for well-defined graft copolymerization of styrene (St) monomer from cellulose (Cell) backbone. For this purpose, Cell was acylated by 2-bromoisobutyryl bromide, and then 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) was immobilized onto Cell backbone using a nucleophilic substitution reaction to produce Cell-TEMPO macroinitiator. Afterward, St monomer was grafted onto Cell backbone through “grafting from” technique. The successful synthesis of Cell- g-polystyrene (PSt) copolymer was confirmed using Fourier transform infrared and proton nuclear magnetic resonance spectroscopies and scanning electron microscopy analysis. Finally, Cell- g-PSt/montmorillonite nanocomposite was fabricated through solution intercalation approach. The thermal properties and structural morphology of the resultant nanocomposite were investigated using thermogravimetric analysis and differential scanning calorimetry and transmission electron microscopy, respectively.

A well-de ned amphiphilic poly(styrene-block-acrylic acid) (PSt-b-PAA) block copolymer to prepare a magnetic nanocomposite was synthesized by reversible additionfragmentation chain transfer (RAFT) polymerization. The synthesized PSt and PSt-b-PAA copolymer was characterized using FTIR and 1 H NMR spectroscopies as well as GPC analysis. Afterwards, a PSt-b-PAA/Fe 3 O 4 magnetic nanocomposite was fabricated through the incorporation of Fe3O4 nanoparticles (NPs) into the synthesized block copolymer. The morphology of the fabricated magnetic nanocomposite was observed using SEM and TEM. The SEM image revealed that the PSt-b-PAA/Fe3O4 magnetic nanocomposite had spherical morphology with the mean diameter of 100 nm, approximately. In addition, thermal properties of the synthesized polymers as well as the magnetic nanocomposite were studied using DSC and TGA analyses. The developed nanocomposite may be applied for enzyme immobilization and cell separation.

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