Covalently Linked Nanocomposites:  Poly(methyl methacrylate) Brushes Grafted from Zirconium Phosphonate

Abstract

Fully covalently connected polymer−clay nanocomposites have been prepared by growing the polymer chains from initiator sites on the lamellae of a zirconium phosphonate clay. The zirconium phosphonate material was synthesized with an approximately 1:3 ratio of 4-aminobenzylphosphonate and ethylphosphonate groups (Zr(AbPO3) x (EtPO3)2- x , x ≈ 0.5) in a “solid solution” distribution within the lamellae. After conversion of the amine groups to 2-bromo-2-methylpropionamide moieties, composites of the zirconium phosphonate and tethered poly(methyl methacrylate) (PMMA) brushes were synthesized by atom transfer radical polymerization (ATRP); the tethered initiator within Zr(Init-AbPO3) x (EtPO3)2- x and its soluble analogue are the first examples of aromatic amide-based initiators for ATRP. To facilitate characterization of the composites, the polymerization conditions were intentionally not optimized for high molecular weight polymer, but PMMA was nonetheless formed at the conditions studied, and the weight fraction of polymer was observed to increase with polymerization time. A combination of thermogravimetric analysis, 13C CP MAS NMR, X-ray diffraction, and scanning electron microscopy confirmed the compositions and structures of the composites, including the covalent connectivity among all of the components.

Modification of polysulfone membranes via surface-initiated atom transfer radical polymerization

“…In recent years, surface-initiated atom transfer radical polymerization (ATRP) is successfully applied to perform surface modification of organic and inorganic materials. And surface-initiated ATRP allows the preparation of well-defined polymer brushed with dormant chain ends on various types of substrates [16][17][18][19][20]. In this method, as the initiators of ATRP, reactive alkyl halide groups on surface are necessary.…”

Surface initiated ATRP of acrylic acid on dopamine‐functionalized AAO membranes

“…ATRP has been used to grow polymers from a variety of substrates, including flat, convex, and concave surfaces, such as gold, magnetic nanoparticles, carbon nanotubes, silica, etc. [12][13][14][15][16][17][18][19][20][21] Depending on the geometry, the growing chains will experience different degrees of confinement that may ultimately affect the chain molecular weight and molecular weight distribution. Although confinement effects are not severe for small spheres, when polymer brushes are grown on flat or concave surfaces strong spatial restrictions exist.…”

A carbon network backbone polymer functionalized with polymer brushes

“…[1][2][3][4][5][6] Polymer brush-modified substrates have been proven to be useful in increasing miscibility for polymer blends and composites, [7][8][9][10] in coatings for materials [11][12][13] and in the generation or support of organic and metallic nanoparticles. [14][15][16][17] Owing to their inherent utility, a wide range of methods for the attachment of polymer brushes to a given substrate have been reported.…”