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Abstract: Polymer Layered Silicate Nanocomposites based on a commercial grade resol were produced using a simple, low labor cost, mechanical approach which allowed to avoid the process of intercalative polymerization of phenol and formaldehyde. Commercial compatibilized montmorillonite was selected as the main nanoreinforcement, while the matrix was a resol diluted in methanol. The aim of this work was to optimize the production technique of the above mentioned nanocomposites. Therefore intercalation of the resin was promoted by high speed mixing, and the processing parameters were varied in order to find the optimum dispersion. The produced nanocomposites were characterized and compared by means of X-ray diffraction, SEM and thermogravimetric analysis. The results of the characterization tests indicated that it was possible to obtain a good degree of dispersion as well as and uniform distribution of the nanoclay platelets. However, TGA measurements showed that the introduction of well dispersed nanoclays did not result in a consistent improvement of thermal stability respect that of the neat resol. [Copyright &y& Elsevier]

Abstract: The intrinsic ability of block copolymers to self-assemble at nanoordered level into different nanoscale structures has been used in this study to obtain nanocomposites. Ordered architectures of silver nanoparticles confined in a poly(styrene-b-isoprene-b-styrene) (SIS) block copolymer matrix have been generated. Both cetyl trimethylammonium chloride (TMAC) and dodecanethiol (DT) were used as surfactants to obtain dispersed nanocomposite films. Morphologies generated in Ag/SIS nanocomposites, detected through atomic force, resulted to be more dependent on the amount of silver nanoparticles than on the other variables chosen in the present study such as amount and type of surfactant and preparation parameters. The experimental observations are consistent with phase diagram predictions obtained for hybrid systems composed of block copolymers and nanoparticles. [Copyright &y& Elsevier]

Abstract: In this paper, the electrical and dielectric properties of epoxy composites containing multi walled carbon nanotubes (MWCNTs) are investigated by means of direct and alternate current measurements and correlated with the internal composite microstructure. A systematically study on the role of different nanotube network structures produced by varying the processing parameters: sonication time and curing temperature is performed. The percolation behavior of the produced composites is studied and the correlation between carbon nanotube networks induced by processing and the final properties is analyzed. An equivalent electrical circuit is proposed as a model to describe the dielectric property behavior due to different multi-scale composite microstructure and the interaction between tubes–tubes and tubes–matrix. [Copyright &y& Elsevier]

Abstract: We report the study of the effects of carbon nanofibers (CNFs) on the cure kinetics and on the chemorheology of unsaturated polyester resins (UP). Two main experimental techniques were utilized: differential scanning calorimetry and rheometry. Isothermal and dynamic tests were performed on the neat polyester resin and on two nanocomposite systems, with 0.5 and 1.0wt.% of CNFs. Furthermore, a TGA study of the selected systems at different isothermal temperatures was performed to evaluate the styrene consumption and related loss rate during the curing process. Subsequently, a phenomenological model (autocatalytic approach) was applied to the experimental data, both in isothermal and dynamic conditions. In the case of dynamic curing, the evidence of multiple peaks in the heat flow curves was studied through the deconvolution of the overall reaction thermogram in single reaction steps. An empirical rheological model coupled with the reaction kinetics was successfully applied to simulate the viscosity changes of the UP matrix. Experimental and modelling results demonstrate the presence of a delay effect of the CNFs on the cure of the UP resin matrix. [Copyright &y& Elsevier]

Abstract: In this work, we propose a chemorheological study of an epoxy resin cured with carboxy-double-walled carbon nanotubes (C-DWNTs) reacted with N-methyldiethanolamine (MDEA). The results showed that 1wt.% C-DWNTs speed up the cure process of more than 40min. The NMR analysis suggests that a possible explanation of these findings is due to the interaction between the carboxylic functionalities of the DWNTs with the MDEA amine groups creating the –NHCO groups. Finally, an excellent agreement between the chemorheological model and the experimental data was found. [Copyright &y& Elsevier]