engleski

Poly(Alkyl Methacrylate)Nanocomposites with Alkyl Ester Functionalized Multiwall Carbon Nanotubes

Carbon nanotubes are often used as a filler to enhance polymer matrices, but in order to benefit from their superior properties they must have good interactions and be well dispersed within the polymer matrix. Therefore they are often functionalized with surface groups via covalent or non-covalent linkage. In this study the influence of methyl and dodecyl ester groups covalently attached to multiwall carbon nanotubes (MWCNT) on their dispersion and interactions with methacrylate based matrices, as well as resulting nanocomposite properties were investigated. Poly(methyl methacrylate) and poly(methyl methacrylate-co-octadecyl methacrylate) based nanocomposites were prepared by free radical in situ polymerization. Oxidized, methyl ester and dodecyl ester functionalized MWCNT were added as 1 wt. % filler in monomer(s) solution. Influence of differently functionalized MWCNT on the molar mass distribution of prepared polymers was examined. In case of homopolymer, addition of functionalized MWCNT caused decrease in average of molar masses, while in copolymer average molar masses did not change significantly. Dispersion of MWCNT and morphology of nanocomposites were studied by scanning electron microscopy (SEM). Prepared nanocomposites were examined by dynamic mechanical analysis (DMA) in order to determine glass transition temperature and viscoelastic functions (storage modulus, loss modulus and tan delta). Both SEM and DMA results show high dependency on the type of used MWCNT. Differential scanning calorimetry was used to investigate influence of functionalized MWCNT on phase changes in nanocomposites. The glass transition temperature decrease amounts between 9 °C - 14 °C in homopolymer nanocomposites, while in copolymer nanocomposites there is no similar effect except for oxidized MWCNT.

Carbon nanotube; functionalization alkyl-methacrylate

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