Solution-state self-assembly of novel poly(carbamoyl methacrylate)s synthesized via combining Passerini three-component reactions and free radical polymerizations

Abstract

Coupling multicomponent reactions (MCRs) with other polymerizations has excellent advantages in inducing multifunctionality and syntheses of complex macromolecular structures. Herein, a straightforward combination method using aqueous Passerini three-component reaction (P3CR(aq)) and conventional free radical polymerization (FRP) (termed as P3CR(aq)-Є-FRP) was applied using mild conditions. Firstly, an environmental-friendly and efficient aqueous P3CR was applied to synthesize various carbamoyl methacrylate (CMA) monomers from methacrylic acid, cyclohexyl isocyanide, and four different aldehydes with high yield (ca. 90 %) and purity. This is plausibly prompted by the key factors of high cohesive energy density of water and facile isolation by the poor solubility of CMAs in aqueous. Then, poly(carbamoyl methacrylate)s (PCMAs) were obtained via FRP with 2,2′-azobis(isobutyronitrile) (AIBN) in dimethylformamide (DMF). Characterizations of both synthesized noble monomers, polymers, solubilities in different solvents, and thermal properties, as well as the solution-state self-assembly behaviors of the polymers by dynamic light scattering (DLS), scanning electron microscope (SEM), and small-angle X-ray scattering (SAXS), including micellized particle sizes, critical micelle concentrations (CMCs), and micelle morphology, were investigated. PCMAs can self-assemble into stable globular micellar nanoparticles (ca. 170–310 nm) with low CMC values (1.6 × 10−5–4.0 × 10−9 mg/mL).