engleski

Synthesis and characterization of styrene and methacrylate copolymers with functionalized multiwall carbon nanotubes composites

In this work composite materials of improved properties based on styrene and methacrylate copolymers with differently functionalized multiwalled carbon nanotubes (CNT) were prepared. In order to obtain a fine dispersion and to enhance the interfacial interaction of CNT with surrounding polimeric matrix an chemical modification of the surface of carbon nanotubes was performed. Various types of functionalized multiwall carbon nanotubes were used: oxidized (CNT-COOH) and their ester analogues (methyl, dodecyl and ethylbenzene). Reaction of covalent functionalization of CNT-COOH with NaOH and further with (2-bromethyl)-benzene and hexadecyl-trimethylammonium bromide into CNT-COOEtBz was successfully performed. Also, oxidized multiwall carbon nanotubes were reacted with thionyl chloride and further in esterification reaction with given alcohols gave corresponding methyl or n-dodecyl ester. Functionalization of CNTs was confirmed by FTIR, Raman and X-ray photoelectron spectroscopy as well as by thermogravimetric analysis. Dodecyl and ethylbenzene ester modified carbon nanotubes showed contact angle for water of about 150 and 141 degrees, while the oxidized and methyl ester modified carbon nanotubes showed seepage. Dispersibility of all modified carbon nanotubes in methanol and toluene was quantified by UV-Vis spectroscopy and differs significantly in both solvents for all systems, due to significant change in chemistry of surface of CNTs. Mixtures of styrene / methacrylate monomer with 1 wt. % of CNT in toluene were reacted in a radical in-situ polymerization reaction. The synthesized composites were characterized by the SEC, TGA, DSC, DMA, SEM and contact angle method. The increase in the properties of polymer/CNT composite can be assigned to better interaction between nanotubes and the polymer matrix.

polymer nanocomposites; carbon nanotubes; chemical functionalization

Dijelom financirano i iz sredstava projekta HRZZ NanFun.