| Zdroj: |
Littunen, K, Hippi, U, Johansson, L-S, Österberg, M, Tammelin, T, Laine, J & Seppälä, J 2011, ' Grafting of nanofibrillated cellulose by free radical polymerization ', 241st American Chemical Society National Meeting & Exposition, Anaheim, United States, 27/03/11-31/03/11 . |
| Popis: |
Grafting of polymer chains from nanofibrillated cellulose surface has been performed in aqueous suspension by a redox initiated free radical polymerization. Several acrylic monomers have been used, their polymerization behavior studied and structure of the products verified. The method was found very efficient and selective: graft copolymerization was dominant over homopolymerization, and up to 80% of polymer in the product was gained. Their structures were very different. Poly(butyl acrylate) (PBuA) formed very long chains, which were situated on the nanofibril surface fairly far apart. Poly(glycidyl methacrylate) (PGMA), on the other hand, showed a very dense coating on nanofibrils and the chains were relatively short. Thus the structures of the materials varied from coated cellulose nanofibrils to a continuous polymer matrix where the nanofibrils were embedded. |
