Effect of processing on rheological properties and structure development of EPOXY/MWCNT nanocomposites
- 144 Downloads
Polymer nanocomposites of epoxy resin containing multiwall carbon nanotubes (external diameter ~30 ± 10 nm, approximate length 10–20 μm) are studied using a rheological approach to determine the stage of debundling of the nanofiller in the epoxy matrix and the development of the rheological properties and structure with time. The role of processing for nanotube dispersion and structure formation is also determined by polarized microscopy and Raman spectrometry. Functionalization with amine groups is applied for part of the samples (mixing the nanotubes in amine hardener followed by mixing in appropriate amounts of epoxy resin). Further on the experimental procedure has been optimized and samples within the concentration range from 0 to 1.0 wt% have been prepared by applying high speed mechanical mixing and ultrasonic treatment with power of 250 W. The results show that chemical functionalization with amine groups contributes to significant changes in the rheological properties and hence in the structure of the composites, as proved by Raman and POM results, indicating better deaggregation of the carbon nanotubes in the amine hardener and chemical bonding of the amine groups attached to the functionalized nanotube surface with the epoxy matrix. The evolution of the dynamic viscosity in the process of polymerization reveals some interesting aspects as retarded curing in the viscometer cell, compared to the control sample under the same conditions, prolonged polymerization time owing to the applied shear rates and carbon nanotube content.
KeywordsEpoxy/MWCNT composites Rheokinetic evolution of dynamic viscosity Raman spectra POM micrographs Polymers
The study is supported by several projects: D01-469/06, D01-463/06 and DO 02-53/08, NSF-Bulgaria; FP7-CSA-NaPolyNet. We acknowledge our gratitude to Dr. C. Taeschner (IFW Dresden) for the supply of MWCNT.
- Ahir SV, Terentjev EM (2007) Polymers containing carbon nanotubes: active composite materials. In: Nalwa HS (ed) Polymeric nanostructures and their application, vol 1. American Scientific Publishers, Valencia, p 1000Google Scholar
- Ivanov E, Nesheva D, Krusteva E, Dobreva T, Kotsilkova R (2009) Rheological and electrical properties of epoxy nanocomposites filled with multiwalled carbon nanotubes. In: Balabanova E, Dragieva I (eds) Nanoscience and Nanotechnology, vol 9. Sofia, Bulgaria, pp 40–43Google Scholar
- Ivanov E, Kotsilkova R, Krusteva E, Logakis E, Kyritsis A, Pissis P, Silvestre C, Duraccio D, Pezzuto M (2010) Effects of processing conditions on rheological, thermal and electrical properties of multiwalled carbon nanotube/epoxy resin composites. J Polymer Sci B Phys (in press)Google Scholar
- Kotsilkova R (ed) (2007) Thermosetting composites for engineering application. Rapra Smiths Group, Shrewsbury, p 325Google Scholar
- Malkin AY, Kulichikhin SG (1996) Rheokinetics: Rheological transformation in synthesis and reaction of oligomers and polymers. Huthing & Wepf Verlag, HeidelbergGoogle Scholar
- Rosendale D, Biesenberger JA (1990) Rheokinetic measurement of step- and chain-addition polymerizations. Advance Chem Series 227:267Google Scholar