Multi-walled carbon nanotubes effect in polypropylene nanocomposites

Abstract

The paper presents a study concerning thermoplastic nanocomposites having polypropylene as the matrix and different contents of carboxyl-functionalized multi-walled carbon nanotubes as the nanofiller. The materials are obtained by melt compounding the nanofiller powder and polymer pellets through the extrusion process followed by injection molding into specific-shape specimens. The materials are evaluated in terms of mechanical properties such as the tensile and flexural strengths and moduli, the thermal stability under load (the heat deflection temperature) and the thermal-behavior properties using a TG-DSC analysis. The fracture cross-section is analyzed using FTIR spectroscopy and SEM microscopy to evaluate the bulk characteristics of the materials. The results show positive effects of the nanofiller addition to the thermoplastic polymer on the mechanical strength and modulus of the materials during flexural and tensile tests, while in the case of the thermal stability under load, the nanofiller addition has a minor influence on the heat-deflection-temperature values. Keywords: polypropylene, melt mixing, carbon nanotubes, mechanical properties, thermal resistancê lanek predstavlja {tudijo termoplasti~nih nanokompozitov s polipropilensko osnovo in razli~no vsebnostjo s karboksilom obdelanih, ve~stenskih ogljikovih nanocevk kot nanopolnilom. Materiali so bili dobljeni iz taline, sestavljene iz prahu nanopolnila in peletov polimerov, s postopkom ekstruzije, ki mu je sledilo tla~no litje vzorcev. Materiali so ocenjeni glede mehanskih lastnosti, kot so natezna in upogibna trdnost in moduli, toplotne stabilnosti pri obremenitvi (deformacijska toplota) in toplotne zna~ilnosti z uporabo TG-DSC analize. Za oceno zna~ilnosti osnovnega materiala je bil analiziran prelom s pomo~jo FTIR spektroskopije in SEM mikroskopije. Rezultati ka`ejo pozitivne u~inke vpliva dodatka nanopolnila termoplasti~nemu polimeru na mehansko trdnost in module materiala pri upogibnem in nateznem preizkusu, medtem ko ima dodatek nanopolnila manj{i vpliv na vrednosti deformacijske toplote pri obremenitvi.

Optimization and assessment of MWCNT dispersion in polypropylene nanocomposite films

“…Presence of polypropylene constituents include C–H stretch vibration modes identified in peaks between 2800 cm −1 to 2950 cm −1 whereas C–H bending vibrations were identified in between 1376 cm −1 to 1480 cm −1 . 39–42…”