Influence of carbon nanotubes on the rheology and dynamic mechanical properties of polyamide-12 for laser sintering

The rheological behaviour of polymer nanocomposites is very important for polymer processing and understanding the structure-properties relationship. In this paper, the rheological properties of a polyamide 12 (PA12) - carbon nanotube (CNT) nanocomposite for laser sintering were studied. Compared to neat PA12, the presence of CNTs resulted in higher storage modulus (G′), loss modulus (G″) and viscosity (η). With an increase in temperature, viscosity showed an unusual increase for both PA12 and the PA12-CNT nanocomposites, which is likely to result from incomplete melting of powder particles. Dynamic mechanical analysis was carried out to examine the effect the CNTs were having on the laser sintered parts. The laser sintered PA12-CNT nanocomposite had an increased elastic modulus compared to that of neat PA12. The CNT and polymer matrix interaction hindered the chain motions, which resulted in higher loss modulus and decreased the thermal expansion coefficient.

[1]  Ruth D. Goodridge,et al.  Processing of a Polyamide-12/carbon nanofibre composite by laser sintering , 2011 .

[2]  Christopher W. Macosko,et al.  Rheology: Principles, Measurements, and Applications , 1994 .

[3]  David W. Rosen,et al.  Additive Manufacturing Technologies: Rapid Prototyping to Direct Digital Manufacturing , 2009 .

[4]  Jie Jin,et al.  An analysis on enhancement of fatigue durability of polyurethane by incorporating organoclay nanofillers , 2006 .

[5]  Tianxi Liu,et al.  Carbon Nanotubes Reinforced Nylon-6 Composite Prepared by Simple Melt-Compounding , 2004 .

[6]  Neil Hopkinson,et al.  Rapid manufacturing : an industrial revolution for the digital age , 2006 .

[7]  F. Klocke,et al.  Consolidation phenomena in laser and powder-bed based layered manufacturing , 2007 .

[8]  J. Sauer,et al.  Investigations of the dynamic mechanical properties of some polyamides , 1960 .

[9]  V. Mittal.  Optimization of Polymer Nanocomposite Properties , 2010 .

[10]  Mo Song,et al.  Preparation and characterization of polyurethane-carbon nanotube composites. , 2005, Soft matter.

[11]  E. Giannelis,et al.  Rheology of End-Tethered Polymer Layered Silicate Nanocomposites , 1997 .

[12]  Tianxi Liu,et al.  Melt rheological properties of nylon 6/multi-walled carbon nanotube composites , 2008 .

[13]  V. E. Beal,et al.  Microstructural and mechanical characterization of PA12/MWCNTs nanocomposite manufactured by selective laser sintering , 2011 .

[14]  Mo Song,et al.  Improving the mechanical properties of laser-sintered polyamide 12 through incorporation of carbon nanotubes , 2013 .

[15]  Suprakas Sinha Ray,et al.  POLYMER/LAYERED SILICATE NANOCOMPOSITES: A REVIEW FROM PREPARATION TO PROCESSING , 2003 .

[16]  H. Ebadi-Dehaghani,et al.  Effect of nano-CaCO3 on rheological and dynamic mechanical properties of polypropylene: Experiments and models , 2011 .

[17]  Suman Das,et al.  Processing and characterization of a carbon black-filled electrically conductive Nylon-12 nanocomposite produced by selective laser sintering , 2010 .

[18]  O. Park,et al.  Phase morphology and rheological behavior of polymer/layered silicate nanocomposites , 2001 .

[19]  Meysam Rahmat,et al.  Carbon nanotube–polymer interactions in nanocomposites: A review , 2011 .

[20]  R. Gupta,et al.  Polymer and Composite Rheology , 2000 .

[21]  M. Okamoto,et al.  Percolated Network Structure Formation and Rheological Properties in Nylon 6/Clay Nanocomposites , 2013 .

[22]  M. Jhon,et al.  Rheology of Poly(ethylene oxide)/Organoclay Nanocomposites , 2001 .

[23]  C. Armstrong,et al.  Structure-Property Relationships in Biaxially Deformed Polypropylene Nanocomposites , 2010 .

[24]  R. Hague,et al.  Laser sintering of polyamides and other polymers , 2012 .

[25]  Neil Hopkinson,et al.  Effects of processing on microstructure and properties of SLS Nylon 12 , 2006 .