Synthesis and characterization of inherently radiopaque nanocomposites using biocompatible iodinated poly(methyl methacrylate-co-acrylamide) and graphene oxide

New inherently radiopaque nanocomposites were prepared using iodine-containing poly(methyl methacrylate-co-acrylamide) and graphene oxide. For this purpose, P(MMA-co-AA) was synthesized via copolymerization of methyl methacrylate and acrylic acid, and modified with 4-iodophenyl isocyanate and 3,4,5-triiodophenyl isocyanate to form poly[(methyl methacrylate-co-(N-4-iodophenyl)acrylamide)] (1I-P(MMA-co-AA)) and poly[(methyl methacrylate-co-(N-3,4,5-triiodophenyl)acrylamide)] (3I-P(MMA-co-AA)), respectively. For comparative evaluation, the non-iodinated copolymer (PIC-P(MMA-co-AA)) was prepared via reaction of the P(MMA-co-AA) with phenyl isocyanate to investigate the effect of iodinated substituents on the morphology and thermal characteristics of the nanocomposites. All the nanocomposites were characterized by X-ray diffraction analysis, scanning electron microscopy, X-radiography and thermogravimetric analysis. The results proved that thermal properties of the nanocomposites improved by the introduction of different amounts of graphene oxide into the copolymers' matrix. Radiopacity measurements showed the excellent radiopacity of iodinated nanocomposites and proved that 3I-GO-5 had radiopacity equivalent to that of an aluminium wedge with 2-mm thickness. Graphic abstract