Polypropylene nanocomposites based on C60-decorated carbon nanotubes: thermal properties, flammability, and mechanical properties

In the present study, the effects of covalently functionalized carbon nanotubes (CNTs) decorated with C60 (abbr. C60-d-CNT) on thermal, flame retardancy and mechanical properties of polypropylene (PP) are investigated. Compared with pristine CNTs, the C60-d-CNT is more easily dispersed in the PP matrix through reactive compatibilization. With the incorporation of C60-d-CNT, thermal oxidation degradation of PP is considerably delayed. Compared to PP, at 1.0 wt% loading of C60-d-CNT, the initial degradation temperature (T5) and maximum weight loss temperature (Tmax) in air are enhanced by 68 °C and 87 °C, respectively. Furthermore, incorporating 1.0 wt% C60-d-CNT can remarkably reduce the peak heat release rate (PHRR) by 71% relative to that of PP, and slow down the combustion process to some extent. The free-radical trapping effect of C60 and the CNTs network are responsible for the improved thermal and flame retardancy properties. Meanwhile, addition of C60-d-CNT also causes enhanced mechanical properties of PP nanocomposites to a certain degree.

[1]  S. Iijima.  Helical microtubules of graphitic carbon , 1991, Nature.

[2]  P. Ajayan.  Nanotubes from Carbon. , 1999, Chemical reviews.

[3]  Angel Rubio,et al.  Single‐Walled Carbon Nanotube–Polymer Composites: Strength and Weakness , 2000 .

[4]  A. Hirsch.  Functionalization of single-walled carbon nanotubes. , 2002, Angewandte Chemie.

[5]  M. Shaffer,et al.  Fabrication and Characterization of Carbon Nanotube/Poly(vinyl alcohol) Composites , 1999 .

[6]  S. Webber,et al.  Free radical copolymerization of styrene and C60 , 1996 .

[7]  W. Blau,et al.  Selective Positioning and Density Control of Nanotubes within a Polymer Thin Film , 2003 .

[8]  Pingan Song,et al.  Fabrication of fullerene-decorated carbon nanotubes and their application in flame-retarding polypropylene. , 2009, Nanoscale.

[9]  M. Prato,et al.  Functionalized carbon nanotubes for plasmid DNA gene delivery. , 2004, Angewandte Chemie.

[10]  X. Zhang,et al.  Fullerenes as a tert-Butylperoxy Radical Trap, Metal Catalyzed Reaction of tert-Butyl Hydroperoxide with Fullerenes, and Formation of the First Fullerene Mixed Peroxides C60(O)(OOtBu)4 and C70(OOtBu)10 , 2002 .

[11]  Pingan Song,et al.  C60 reduces the flammability of polypropylene nanocomposites by in situ forming a gelled-ball network , 2008, Nanotechnology.

[12]  Kostas Kostarelos,et al.  Rational design and engineering of delivery systems for therapeutics: biomedical exercises in colloid and surface science. , 2003, Advances in colloid and interface science.

[13]  Hongjie Dai,et al.  Carbon nanotubes: synthesis, integration, and properties. , 2002, Accounts of chemical research.

[14]  Günter Beyer,et al.  Short communication: Carbon nanotubes as flame retardants for polymers , 2002 .

[15]  Q. Yuan,et al.  A mechanistic study of fire retardancy of carbon nanotube/ethylene vinyl acetate copolymers and their clay composites , 2005 .

[16]  Richard H. Harris,et al.  Nanoparticle networks reduce the flammability of polymer nanocomposites , 2005, Nature materials.

[17]  Pingan Song,et al.  Flame-retardant-wrapped carbon nanotubes for simultaneously improving the flame retardancy and mechanical properties of polypropylene , 2008 .

[18]  G. Beyer.  Filler blend of carbon nanotubes and organoclays with improved char as a new flame retardant system for polymers and cable applications , 2005 .

[19]  Mei Gao,et al.  Aligned Coaxial Nanowires of Carbon Nanotubes Sheathed with Conducting Polymers , 2000 .

[20]  Pingan Song,et al.  Thermal degradation and flame retardancy of polypropylene/C60 nanocomposites , 2008 .

[21]  Kathryn M. Butler,et al.  Thermal and flammability properties of polypropylene/carbon nanotube nanocomposites , 2004 .

[22]  C. A. Wilkie,et al.  Polyethylene and polypropylene nanocomposites based on a three component oligomerically-modified clay , 2006 .

[23]  B. Tang,et al.  Direct Fullerenation of Polycarbonate via Simple Polymer Reactions , 1997 .

[24]  Yuehua Wu,et al.  Fabrication of dendrimer-like fullerene (C60)-decorated oligomeric intumescent flame retardant for reducing the thermal oxidation and flammability of polypropylene nanocomposites , 2009 .

[25]  Xuecheng Chen,et al.  Catalyzing Carbonization of Polypropylene Itself by Supported Nickel Catalyst during Combustion of Polypropylene/Clay Nanocomposite for Improving Fire Retardancy , 2005 .

[26]  T. Kashiwagi,et al.  Thermal Degradation and Flammability Properties of Poly(propylene)/Carbon Nanotube Composites , 2002 .

[27]  Zhongbin Xu,et al.  Functionalizing Carbon Nanotubes by Grafting on Intumescent Flame Retardant: Nanocomposite Synthesis, Morphology, Rheology, and Flammability , 2008 .

[28]  K. Preston,et al.  Radical Reactions of C60 , 1991, Science.

[29]  T. Kashiwagi,et al.  Flammability properties of polymer nanocomposites with single-walled carbon nanotubes: effects of nanotube dispersion and concentration * , 2005 .