CHARACTERIZATION OF MELT MIXED PP COMPOSITES WITH NEW NANOSTRUCTURED CARBON MATERIALS. Raul Rivas Mentor: Dr. Vicki Flaris

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1 CHARACTERIZATION OF MELT MIXED PP COMPOSITES WITH NEW NANOSTRUCTURED CARBON MATERIALS Raul Rivas Mentor: Dr. Vicki Flaris

2 Outline Focus Materials Prepara8on Surface Energy Measurements Surface Energy Results Electrical Measurements Resis8vity Results Conclusions

3 Polypropylene (PP) with four different carbon based fillers: Single- walled carbon nanotubes (SWCNTs) Mul8- walled carbon nanotubes (MWCNTs) Nanodiamonds (ND) Nanohorns (CNH) Carbon nanofillers can enhance Electrical conduc8vity Mechanical strength Thermal expansion Thermal conduc8vity Scratch and wear behavior Oxida8on Stability Flame Retardancy

4 The environmental benefits of working with these materials include: Amount of filler used to form the composites is small which means material waste is reduced Polypropylene and carbon allotropes are more abundant when compared to the shrinking availability of metals like copper or silver May poten8ally be used as a replacement for components in some electrical devices which can help reduce electronic waste

5 Materials Polypropylene Moplen HP400R (Lyondell Basell, Netherlands) MFI 25 g/10 min (low viscous grade) SWCNTs (Fraunhofer- Ins8tut für Werkstoff- und Strahltechnik IWS, Germany, carbon purity ca. 80 wt%, ca.10 wt% free and ca. 10 wt% encapsulated metal par8cles) MWCNTs (Nanocyl N7000, purchased from Nanocyl S.A., Belgium, carbon purity > 90wt%, ca. 10 wt% metal oxide) Carbon nanohorns (CNH, TIE GmbH, Germany, carbon purity > 99 wt%) Nanodiamonds (ND, Carbodeon Ltd Oy, Finland, >97 wt% nanodiamants, < 1.2 wt% metallic impuri8es, < 2.5 wt% oxidisable carbon).

6 Multi-walled carbon nanotubes (MWCNTs)* Nanodiamonds (ND)* * From datasheet Nanocyl NC 7000 (Nanocyl, Sambreville, Belgium) * From datasheet Nanodiamonds, Carbodeon, Molto Nuevo

7 Nanohorns (CNH) Single-walled CNTs (SWCNTs) TIE GmbH (Griesheim, Deutschland) Fraunhofer Single Wall Carbon Nanotubes SQ (IWS Dresden, Germany, arc process, nonpurified and nontreated, wt% SWCNT, 20 wt% catalyst, wt% graphite)

8 Preparation Compounded using a DSM Xplore 15cm³ microcompounder The composites were processed at 210 C for 5 minutes and 250rpm Plates were compression molded for electrical and surface energy measurements (diameter 60 mm, thickness 0.5 mm) using a Weber PW 40 EH hot press (Paul- Oho Weber GmbH, Germany) at 210 C, 50 kn for 2 minutes.

9 Surface Energy Measurements Young s equa;on Krüss MODEL DSA- 10 Measured on compression molded plates

10 Surface Energy Zisman Theory (one- component model) The surface energy of the solid is equal to the surface tension of the highest surface tension liquid that will completely wet the solid with a contact angle of 0. Zisman plot - liquid surface tension versus cos θ - extrapolated to cosθ=1. It is best for non- polar surfaces.

11 Contact angle of composites (large diameter syringe) Materials Contact angle ( ) 5% filler loading Contact angle ( ) 10% filler loading PP+CNH PP+MWCNTs PP+ND PP+SWCNTs Surface tension data for materials at RT using heptane (PP with no filler has a contact angle of 9.7 )

12 Zisman Model (large diameter syringe) Materials Surface tension (mn/ m) 5% filler loading Surface tension (mn/ m) 10% filler loading PP+CNH PP+MWCNTs PP+ND PP+SWCNTs Surface tension data (Zisman model) PP with no filler has a surface tension of 26.9 mn/m

13 Contact angle of composites (small diameter syringe) Materials Contact angle ( ) 5% filler loading Contact angle ( ) 10% filler loading PP+CNH PP+MWCNTs PP+ND PP+SWCNTs Surface tension data for materials at RT using heptane (PP with no filler has a contact angle of 7.2 )

14 Zisman Model (small diameter syringe) Materials Surface tension (mn/ m) 5% filler loading Surface tension (mn/ m) 10% filler loading PP+CNH PP+MWCNTs PP+ND PP+SWCNTs Surface tension data (Zisman model) PP with no filler has a surface tension of 29.6 mn/m

15 Electrical Measurements Test Fixtures: Keithley 8009 Resistivity Test Fixture Strip cell Electrometer: Keithley 6517 A Electrometer Keithley DMM 2000 For high resistive samples (R > 10 7 Ω ) Plate cell a) R For high conductive samples (R < Ω ) Strip cell U I 1 U 2

16 10 16 volume resistivity [Ohm cm] PP processed CNH SWCNT MWCNT ND filler content (wt.%) Electrical volume resis8vity of PP based nanocomposites vs. filler content *Currently we are trying to develop novel ways of measuring the conduc8vity of the samples using the AFM at BCC

17 Conclusions The CNT based composites show in summary beher electrical conduc8vity as compared to CNH and ND CNTs increase the electrical characteris8cs of PP the most MWCNTs seem to be more effec8ve than SWCNTs Surface tension data (Zisman model) showed increased values only in composites with CNHs and MWCNTs indica8ng beher paintability, whereas SWCNTs and NDs based composites behaved quite similar to PP Surface tension of the samples showed a decrease when using the smaller syringe as compared to the larger syringe

18 Acknowledgements Thanks to my mentor Dr. Vicki Flaris. Thanks to Dr. Petra Pötschke and her group in Germany for the electrical measurements. Thanks to LSAMP for financial support.