Zinc-Containing Block Copolymer as a Precursor for the in Situ Formation of Nano ZnO and PMMA/ZnO Nanocomposites

• Published in: Macromolecules 2013-09, Vol.46 (17), p.6942-6948
• Main Authors: Kos, Tomaž, Anžlovar, Alojz, Pahovnik, David, Žagar, Ema, Orel, Zorica Crnjak, Žigon, Majda
• Format: Article
• Language: English
• Subjects: Applied sciences; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Organic polymers; Physicochemistry of polymers; Polymer industry, paints, wood; Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts; Technology of polymers
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma4010296

We report on the synthesis of highly transparent and UV-absorbing PMMA/ZnO nanocomposites prepared by hydrolysis of a ZnO precursor, the A-b-(AB) diblock copolymer, poly(methyl methacrylate)-block-poly(methyl methacrylate-co-(zinc methacrylate acetate)), PMMA-b-P(MMA-co-ZnMAAc), synthesized by RAFT polymerization. The zinc content of the block copolymers was in the range from 3 to 13 wt %. The PMMA block provides inherent compatibility with the PMMA matrix, whereas the second block, P(MMA-co-ZnMAAc) with zinc ions, acts as a polymeric precursor for the formation of ZnO nanoparticles. The amphiphilic block copolymer self-organizes in THF and THF/H2O in ordered nanostructures, thereby influencing the nanoparticle formation during the hydrolysis of the precursor block copolymer with KOH in a solvent mixture THF/H2O. The ZnO nanoparticles were rod-shaped with lengths up to 80 nm and a diameter of 14 nm and were redispersible in THF. Dispersions in THF and thin films of PMMA/ZnO nanocomposite exhibit excellent transparency in the visible range and good absorption in the UV range below 400 nm. The block copolymer was characterized by SEC, NMR, DLS, and TGA, while PMMA/ZnO nanocomposites were characterized by IR, XRD, UV–vis, and STEM.