Formation and Characterization of Anchored Polymer Coatings on Alumina

Maleic acid adsorbed on alumina can copolymerize with 1-alkenes to form monolayers of polymer coatings that are tightly anchored on the alumina surface. The structure of the copolymer formed on the alumina surface was characterized by means of solid-state 13 C NMR and proton NMR of the extractable polymer fraction. The molecular weight of the extracted polymer was determined using gel permeation chromatography. The conditions for producing a high loading of polymer coating on alumina were optimized. The change of the surface area and pore size of alumina after the formation of the polymer coating was studied by the use of nitrogen adsorption. The morphology of the coated alumina particles was studied by the use of scanning electron microscopy. The stability of polymer-coated alumina was tested against solvent washing, and it was found that poly(maleic acid−1-octadecene) cross-linked with divinylbenzene was stable in many aqueous and nonaqueous solvent systems. Finally, the copolymerization of maleic acid adsorbed on alumina with allyl compounds was explored for possible introduction of other functional groups onto the alumina surface.