Synthesis and Properties of Polypropylene/Multiwall Carbon Nanotube Composites

Abstract

Isotactic polypropylene and elastomeric stereoblock polypropylene nanocomposites containing 0.1−3.5 wt % multiwall carbon nanotubes (MWCNTs) have been synthesized via the in situ polymerization approach using MAO-activated C 2- and C 1-symmetry ansa-zirconocenes, a technique that has not been previously reported in literature. Fracture morphology examination of the nanocomposites revealed very efficient distribution of the MWCNTs within the isotactic polypropylene matrix, yet interfacial adhesion level and the reinforcement efficiency were dependent on the nanotube loadings. The elastomeric stereoblock polypropylene/MWCNT and the isotactic polypropylene-based nanocomposites exhibited different morphologies depending on the synthesis peculiarities. For isotactic polypropylene, Youngʼs modulus increased by ∼22% even at 0.1 wt % MWCNT loading, and further modulus growth was observed at higher filler contents. Relatively low permittivity values and considerable dielectric losses in microwave range infer that the obtained nanocomposites can find use as efficient electromagnetic shielding materials and microwave absorbing filters. Outstanding improvement of thermal stability (∼60 °C at maximum weight loss rate temperature) has been achieved for isotactic polypropylene upon incorporating only 3.5 wt % of carbon nanotubes.

Preparation and characterization of nanocomposites based on COOH functionalized multi-walled carbon nanotubes and on poly(trimethylene terephthalate)

“…Above this content, the strength of the polymer/ CNTs composites decreases, and in some cases, even lower than that of the polymer matrix. For example, the epoxy/CNT [67] and polypropylene/ CNT [68] composites shows the critical CNTs content at about 0.5 wt%. At higher CNTs content, the extent of improvement in mechanical properties might be limited by the high viscosity of the composite and by poor load transfer between CNTs and polymer matrix resulted from imperfect dispersion and not completely covered some surface of the CNTs by polymer matrix due to the large specific area of CNTs.…”

Creep of thermoplastic polyurethane reinforced with ozone functionalized carbon nanotubes

“…Carbon nanotubes (CNTs) can be considered as a promising filler which has attracted great attention and generated intense research on their properties as well as their composites with polymers [7]. Interests in this extraordinary carbon form are mainly focusing on exceptional mechanical, electrical and thermal properties [8][9][10][11][12][13]. These properties, in addition to their very high aspect ratio, make nanotubes excellent candidate for novel composite materials.…”

New strategies for the chemical characterization of multi-walled carbon nanotubes and their derivatives

“…Compared with non-covalently functionalized CNTs, covalently functionalized ones can interact directly with the matrix system as the polymer bound to the CNT can transfer stress directly from the matrix to the CNT structure. [9,14,17,[22][23][24][25][26][27][28] However, the characterization of functionalized CNT is still difficult because of their high absorption of electromagnetic radiation across a broad spectrum [7,8]. This leads to a very low resolution for methods based on radiation like UV/Vis and IR spectroscopy.…”