Grafting of poly[(methyl methacrylate)-block-styrene] onto cellulose via nitroxide-mediated polymerization, and its polymer/clay nanocomposite

• PSt and PMMA were graft and block copolymerized onto cellulose via NMP technique.
• The morphologies of the synthesized samples were studied by means of AFM and SEM.
• The Cell-g-(PSt-b-PMMA)/O-MMT nanocomposite was prepared via a solution method.
• TEM image showed that the MMT lamellae uniformly dispersed within the polymer matrix.
• The nanocomposite showed higher thermal stability in comparison with pure terpolymer.

For the first time, nitroxide-mediated polymerization (NMP) was used for synthesis of graft and block copolymers using cellulose (Cell) as a backbone, and polystyrene (PSt) and poly(methyl metacrylate) (PMMA) as the branches. For this purpose, Cell was acetylated by 2-bromoisobutyryl bromide (BrBiB), and then the bromine group was converted to 4-oxy-2,2,6,6-tetramethylpiperidin-1-oxyl group by a substitution nucleophilic reaction to afford a macroinitiator (Cell-TEMPOL). The macroinitiator obtained was subsequently used in controlled graft and block copolymerizations of St and MMA monomers to yield Cell-g-PSt and Cell-g-(PMMA-b-PSt). The chemical structures of all samples as representatives were characterized by FTIR and 1H NMR spectroscopies. In addition, Cell-g-(PMMA-b-PSt)/organophilic montmorillonite nanocomposite was prepared through a solution intercalation method. TEM was used to evaluate the morphological behavior of the polymer–clay system. It was demonstrated that the addition of small percent of organophilic montmorillonite (O-MMT; 3 wt.%) was enough to improve the thermal stability of the nanocomposite.