Abstract
Processing conditions can significantly influence the structure and properties of polymer nanocomposites. In the present study, melt mixed high density polyethylene (HDPE)/multi-walled carbon nanotube (MWCNT) nanocomposites were prepared via twin-screw extrusion and then compression molded (CM). The effect of heating temperature, pressing time and cooling rate on the structure, electrical and mechanical properties of the CM nanocomposites was systematically investigated. Volume resistivity tests indicate that the nanocomposite with 2 wt.-% MWCNTs, which is in the region of the electrical percolation threshold, is very sensitive to the CM parameters such that heating temperature > pressing time > cooling rate. Generally, the resistivity of nanocomposites decreases with increasing heating temperature and pressing time. Interestingly, the electrical resistivity of the rapidly cooled nanocomposite with 2 wt.-% MWCNTs is about 2 orders lower than that of the slowly cooled nanocomposite which is attributed to the lower crystallinity and smaller crystallites presenting less of an obstacle to the formation of conductive pathways. The tensile properties of the nanocomposite with 2 wt.-% MWCNTs are also influenced by the compression molding parameters to some extent, while those of the nanocomposites with higher MWCNT loading are insensitive to the changes in processing conditions. The modulus of the nanocomposites increases by about 25 to 50 % and 110 to 130 %, respectively, with the incorporation of 2 and 4 wt.-% MWCNTs, which agrees well with the theoretical values predicted from Halpin-Tsai and Mori-Tanaka models. This work has important implications for both process control and the tailoring of electrical and mechanical properties in the commercial manufacture of conductive HDPE/MWCNT nanocomposites.
Kurzfassung
Die Prozessbedingungen können die Struktur und die Eigenschaften von Polymer-Nanokompositen signifikant beeinflussen. In der diesem Beitrag zugrunde liegenden Studie wurden schmelzgemischte hochverdichtete (Melt Mixed High Density Polyethylene) mit mehrwandigen Carbon-Nanoröhrchen (Multi-Walled Carbon Nanotube (MWCNT)) verstärkte Nanokomposite mittels zweischraubiger Extrusion hergestellt und nachfolgend formgepresst. Die Auswirkung der Temperatur, der Pressdauer und der Abkühlungsrate auf die Struktur sowie die elektrischen und mechanischen Eigenschaften der formgepressten Nanokomposite wurde systematisch untersucht. Die Tests bezüglich des Volumenwiderstandes deuten an, dass das Nanokomposit mit 2 wt.-% MWCNT, das in dem Bereich der Schwelle zur elektrischen Durchlässigkeit liegt, sehr sensibel bezüglich der Formpressparameter ist, und zwar mit einem jeweils größeren Effekt der Temperatur gegenüber der Pressdauer und entsprechend der Abkühlungsrate. Allgemein nahm der Widerstand der Nanokomposite mit zunehmender Formpresstemperatur und -dauer ab. Interessanterweise ist der elektrische Widerstand der abgeschreckten Nanokomposite mit 2 wt.-% MWCNT um zwei Größenordnungen niedriger als der der langsam abgekühlten Nanokomposite, was auf die geringere Kristallinität und kleinere Kristallite zurückgeführt wird, die geringeres Hindernis für die Ausbildung von leitenden Pfaden darstellen. Die Zugeigenschaften der Nanokomposite mit 2 wt.-% MWCNT werden ebenfalls innerhalb bestimmter Grenzen durch die Formpressparameter beeinflusst, während diejenigen der Nanokomposite mit größeren MWCNT-Anteilen nicht sensitiv bezüglich der Prozessbedingungen waren. Der Modul der Nanokomposite nahm zwischen 25 und 50 % und entsprechend zwischen 110 und 130 % mit der Zugabe von 2 bzw. 4 wt.-% MWCNT zu, was gut mit den theoretischen Werten unter Vorhersage nach den Halpin-Tsai- und Mori-Tanaka-Modellen übereinstimmt. Die vorliegende Arbeit hat bedeutende Auswirkungen für die Prozesskontrolle und die resultierenden elektrischen und mechanischen Eigenschaften bei der Herstellung von leitenden HDPE/MWCNT-Nanokompositen.
References
1 S. K.Yadav, S. S.Mahapatra, J. W.Cho: Tailored dielectric and mechanical properties of noncovalently functionalized carbon nanotube/poly (styrene-b-(ethylene-co-butylene)-b-styrene) nanocomposites, Journal of Applied Polymer Science129 (2013), No. 4, pp. 2305–231210.1002/app.38938Search in Google Scholar
2 D.Xiang, E.Harkin-Jones, D.Linton: Processability, structural evolution and properties of melt processed biaxially stretched HDPE/MWCNT nanocomposites, RSC Advances4 (2014), No. 83, pp. 44130–4414010.1039/C4RA07166BSearch in Google Scholar
3 D.Xiang, E.Harkin-Jones, D.Linton: Characterization and structure-property relationship of melt-mixed high density polyethylene/multi-walled carbon nanotube composites under extensional deformation, RSC Advances5 (2015), No. 59, pp. 47555–4756810.1039/C5RA06075CSearch in Google Scholar
4 D.Xiang, E.Harkin-Jones, D.Linton, P.Martin: Structure, mechanical, and electrical properties of high-density polyethylene/multi-walled carbon nanotube composites processed by compression molding and blown film extrusion, Journal of Applied Polymer Science132 (2015), No. 42, pp. 42665–4267610.1002/app.42665Search in Google Scholar
5 G.Kasaliwal, A.Göldel, P.Pötschke: Influence of processing conditions in small-scale melt mixing and compression molding on the resistivity and morphology of polycarbonate-MWNT composites, Journal of Applied Polymer Science112 (2009), No. 6, pp. 3494–350910.1002/app.29930Search in Google Scholar
6 J.Shen, M. F.Champagne, R.Gendron, S.Guo: The development of conductive carbon nanotube network in polypropylene-based composites during simultaneous biaxial stretching, European Polymer Journal48 (2012), No. 5, pp. 930–93910.1016/j.eurpolymj.2012.03.005Search in Google Scholar
7 G. Y. H.Choong, C. Y.Lew: Role of processing history on the mechanical and electrical behavior of melt-compounded polycarbonate-multiwalled carbon nanotube nanocomposites, Journal of Applied Polymer Science132 (2015), No. 28, pp. 42277–4228710.1002/app.42277Search in Google Scholar
8 G. L.Hwang, Y. T.Shieh, K. C.Hwang: Efficient load transfer to polymer-grafted multiwalled carbon nanotubes in polymer composites, Advanced Functional Materials14 (2004), No. 5, pp. 487–49110.1002/adfm.200305382Search in Google Scholar
9 D.Gomes, M. R.Loos, M. H.Wichmann, A.de la Vega, K.Schulte: Sulfonated polyoxadiazole composites containing carbon nanotubes prepared via in situ polymerization, Composites Science and Technology69 (2009), No. 2, pp. 220–22710.1016/j.compscitech.2008.10.008Search in Google Scholar
10 Q.Wang, J.Dai, W.Li, Z.Wei, J.Jiang: The effects of CNT alignment on electrical conductivity and mechanical properties of SWNT/epoxy nanocomposites, Composites Science and Technology68 (2008), No. 7, pp. 1644–164810.1016/j.compscitech.2008.02.024Search in Google Scholar
11 T.McNally, P.Pötschke, P.Halley, M.Murphy, D.Martin, S. E. J.Bell, G. P.Brennan, D.Bein, P.Lemoine, J. P.Quinn: Polyethylene multiwalled carbon nanotube composites, Polymer46 (2005), No. 19, pp. 8222–823210.1016/j.polymer.2005.06.094Search in Google Scholar
12 H. B.Zhang, W. G.Zheng, Q.Yan, Y.Yang, J. W.Wang, Z. H.Lu, G. Y.Ji, Z. Z.Yu: Electrically conductive polyethylene terephthalate/graphene nanocomposites prepared by melt compounding, Polymer51 (2010), No. 5, pp. 1191–119610.1016/j.polymer.2010.01.027Search in Google Scholar
13 C.McClory, T.McNally, M.Baxendale, P.Pötschke, W.Blau, M.Ruether: Electrical and rheological percolation of PMMA/MWCNT nanocomposites as a function of CNT geometry and functionality, European Polymer Journal46 (2010), No. 5, pp. 854–86810.1016/j.eurpolymj.2010.02.009Search in Google Scholar
14 R.Socher, B.Krause, M. T.Müller, R.Boldt, P.Pötschke: The influence of matrix viscosity on MWCNT dispersion and electrical properties in different thermoplastic nanocomposites, Polymer53 (2012), No. 2, pp. 495–50410.1016/j.polymer.2011.12.019Search in Google Scholar
15 B.Mayoral, J.Lopes, T.McNally: Influence of processing parameters during small-scale batch melt mixing on the dispersion of MWCNTs in a poly(propylene) matrix, Macromolecular Materials and Engineering299 (2014), No. 5, pp. 609–62110.1002/mame.201300158Search in Google Scholar
16 C.McClory, P.Pötschke, T.McNally: Influence of screw speed on electrical and rheological percolation of melt-mixed high-impact polystyrene/MWCNT nanocomposites, Macromolecular Materials and Engineering296 (2011), No. 1, pp. 59–6910.1002/mame.201000220Search in Google Scholar
17 B.Mayoral, G.Garrett, T.McNally: Influence of screw profile employed during melt mixing on the micro-scale dispersion of MWCNTs in poly(propylene), Macromolecular Materials and Engineering299 (2014), No. 6, pp. 748–75610.1002/mame.201300172Search in Google Scholar
18 M.Morcom, K.Atkinson, G. P.Simon: The effect of carbon nanotube properties on the degree of dispersion and reinforcement of high density polyethylene, Polymer51 (2010), No. 15, pp. 3540–355010.1016/j.polymer.2010.04.053Search in Google Scholar
19 P.Verge, S.Benali, L.Bonnaud, A.Minoia, M.Mainil, R.Lazzaroni, P.Dubois: Unpredictable dispersion states of MWNTs in HDPE: A comparative and comprehensive study, European Polymer Journal48 (2012), No. 15, pp. 677–68310.1016/j.eurpolymj.2012.01.002Search in Google Scholar
20 J.Yang, K.Wang, H.Deng, F.Chen, Q.Fu: Hierarchical structure of injection-molded bars of HDPE/MWCNTs composites with novel nanohybrid shish-kebab, Polymer51 (2010), No. 3, pp. 774–78210.1016/j.polymer.2009.11.059Search in Google Scholar
21 F.Tao, L.Bonnaud, D.Auhl, B.Struth, P.Dubois, C.Bailly: Influence of shear-induced crystallization on the electrical conductivity of high density polyethylene carbon nanotube nanocomposites, Polymer53 (2012), No. 25, pp. 5909–591610.1016/j.polymer.2012.10.026Search in Google Scholar
22 O.Valentino, M.Sarno, N. G.Rainone, M. R.Nobile, P.Ciambelli, H. C.Neitzert, G. P.Simon: Influence of the polymer structure and nanotube concentration on the conductivity and rheological properties of polyethylene/CNT composites, Physica E: Low-Dimensional Systems and Nanostructures40 (2008), No. 7, pp. 2440–244510.1016/j.physe.2008.02.001Search in Google Scholar
23 B.Xu, J.Leisen, H. W.Beckham, R.Abu-Zurayk, E.Harkin-Jones, T.McNally: Evolution of clay morphology in polypropylene/montmorillonite nanocomposites upon equibiaxial stretching: A solid-state NMR and TEM approach, Macromolecules42 (2009), No. 22, pp. 8959–896810.1021/ma901754mSearch in Google Scholar
24 S.Xie, E.Harkin-Jones, Y.Shen, P.Hornsby, M.McAfee, T.McNally, R.Patel, H.Benkreira, P.Coates: Quantitative characterization of clay dispersion in polypropylene-clay nanocomposites by combined transmission electron microscopy and optical microscopy, Materials Letters64 (2010), No. 2, pp. 185–18810.1016/j.matlet.2009.10.042Search in Google Scholar
25 R.Abu-Zurayk, E.Harkin-Jones: The influence of processing route on the structuring and properties of high-density polyethylene (HDPE)/clay nanocomposites, Polymer Engineering and Science52 (2012), No. 11, pp. 2360–236810.1002/pen.23189Search in Google Scholar
26 R.Abu-Zurayk, E.Harkin-Jones, T.McNally, G.Menary, P.Martin, C.Armstrong, M.McAfee: Structure-property relationships in biaxially deformed polypropylene nanocomposites, Composites Science and Technology70 (2010), No. 9, pp. 1353–135910.1016/j.compscitech.2010.04.011Search in Google Scholar
27 T.Villmow, S.Pegel, P.Pötschke, U.Wagenknecht: Influence of injection molding parameters on the electrical resistivity of polycarbonate filled with multi-walled carbon nanotubes, Composites Science and Technology68 (2008), No. 3, pp. 777–78910.1016/j.compscitech.2007.08.031Search in Google Scholar
28 D.Lellinger, D.Xu, A.Ohneiser, T.Skipa, I.Alig: Influence of the injection moulding conditions on the in-line measured electrical conductivity of polymer-carbon nanotube composites, Physica Status Solidi (B)245 (2008), No. 10, pp. 2268–227110.1002/pssb.200879619Search in Google Scholar
29 D. R.Yu, G. H.Kim: Effect of processing parameters on the surface resistivity of ethylene-vinyl acetate copolymer/multiwalled carbon nanotube nanocomposites, Journal of Applied Polymer Science124 (2012), No. 4, pp. 2962–296710.1002/app.35322Search in Google Scholar
30 T.Villmow, P.Pötschke, S.Pegel, L.Häussler, B.Kretzschmar: Influence of twin-screw extrusion conditions on the dispersion of multi-walled carbon nanotubes in a poly(lactic acid) matrix, Polymer49 (2008), No. 16, pp. 3500–350910.1016/j.polymer.2008.06.010Search in Google Scholar
31 R. H.Olley, D. C.Bassett: An improved permanganic etchant for polyolefines, Polymer23 (1982), No. 12, pp. 1707–171010.1016/0032-3861(82)90110-0Search in Google Scholar
32 W.Luo, N.Zhou, Z.Zhang, H.Wu: Effects of vibration force field on structure and properties of HDPE/CaCO3 nanocomposites, Polymer Testing25 (2006), No. 1, pp. 124–12910.1016/j.polymertesting.2005.08.010Search in Google Scholar
33 B.Wunderlich: Macromolecular Physics, Volume 3: Crystal Melting, Academic Press, New York, USA (1980)Search in Google Scholar
34 S.Chakraborty, J.Pionteck, B.Krause, S.Banerjee, B.Voit: Influence of different carbon nanotubes on the electrical and mechanical properties of melt mixed poly(ether sulfone)-multi walled carbon nanotube composites, Composites Science and Technology72 (2012), No. 15, pp. 1933–194010.1016/j.compscitech.2012.08.013Search in Google Scholar
35 F.Nanni, B.Mayoral, F.Madau, G.Montesperelli, T.McNally: Effect of MWCNT alignment on mechanical and self-monitoring properties of extruded PET-MWCNT nanocomposites, Composites Science and Technology72 (2012), No. 10, pp. 1140–114610.1016/j.compscitech.2012.03.015Search in Google Scholar
36 M.Pöllänen, S.Pirinen, M.Suvanto, T. T.Pakkanen: Influence of carbon nanotube-polymeric compatibilizer masterbatches on morphological, thermal, mechanical, and tribological properties of polyethylene, Composites Science and Technology71 (2011), No. 10, pp. 1353–136010.1016/j.compscitech.2011.05.009Search in Google Scholar
37 Y.Xi, A.Yamanaka, Y.Bin, M.Matsuo: Electrical properties of segregated ultrahigh molecular weight polyethylene/multiwalled carbon nanotube composites, Journal of Applied Polymer Science105 (2007), No. 5, pp. 2868–287610.1002/app.26282Search in Google Scholar
38 H.Deng, T.Skipa, R.Zhang, D.Lellinger, E.Bilotti, I.Alig, T.Peijs: Effect of melting and crystallization on the conductive network in conductive polymer composites, Polymer50 (2009), No. 15, pp. 3747–375410.1016/j.polymer.2009.05.016Search in Google Scholar
39 O.Zhou, R.Fleming, D.Murphy, C.Chen, R.Haddon, A.Ramirez, S.Glarum: Defects in carbon nanostructures, Science263 (1994), No. 5154, pp. 1744–174710.1126/science.263.5154.1744Search in Google Scholar PubMed
40 P.Kalakonda, G. S.Iannacchione, M.Daly, G. Y.Georgiev, Y.Cabrera, R.Judith, P.Cebe: Calorimetric study of nanocomposites of multiwalled carbon nanotubes and isotactic polypropylene polymer, Journal of Applied Polymer Science130 (2013), No. 1, pp. 587–59410.1002/app.39204Search in Google Scholar
41 R.Haggenmueller, J. E.Fischer, K. I.Winey: Single wall carbon nanotube/polyethylene nanocomposites: Nucleating and templating polyethylene crystallites, Macromolecules39 (2006), No. 8, pp. 2964–297110.1021/ma0527698Search in Google Scholar
42 R.Zhang, A.Dowden, H.Deng, M.Baxendale, T.Peijs: Conductive network formation in the melt of carbon nanotube/thermoplastic polyurethane composite, Composites Science and Technology69 (2009), No. 10, pp. 1499–150410.1016/j.compscitech.2008.11.039Search in Google Scholar
43 J.Du, L.Zhao, Y.Zeng, L.Zhang, F.Li, P.Liu, C.Liu: Comparison of electrical properties between multi-walled carbon nanotube and graphene nanosheet/high density polyethylene composites with a segregated network structure, Carbon49 (2011), No. 4, pp. 1094–110010.1016/j.carbon.2010.11.013Search in Google Scholar
44 C.Li, E. T.Thostenson, T. W.Chou: Dominant role of tunneling resistance in the electrical conductivity of carbon nanotube-based composites, Applied Physics Letters91 (2007), No. 22, pp. 223114–22311710.1063/1.2819690Search in Google Scholar
45 M.El Achaby, A.Qaiss: Processing and properties of polyethylene reinforced by graphene nanosheets and carbon nanotubes, Materials and Design44 (2013), pp. 81–8910.1016/j.matdes.2012.07.065Search in Google Scholar
46 Z.Jiang, P.Hornsby, R.McCool, A.Murphy: Mechanical and thermal properties of polyphenylene sulfide/multiwalled carbon nanotube composites, Journal of Applied Polymer Science123 (2011), No. 5, pp. 2676–268310.1002/app.34669Search in Google Scholar
47 G. P.Tandon, G. J.Weng: The effect of aspect ratio of inclusions on the elastic properties of unidirectionally aligned composites, Polymer Composites5 (1984), No. 4, pp. 327–33310.1002/pc.750050413Search in Google Scholar
48 T.Fornes, D.Paul: Modeling properties of nylon 6/clay nanocomposites using composite theories, Polymer44 (2003), No. 17, pp. 4993–501310.1016/S0032-3861(03)00471-3Search in Google Scholar
© 2017, Carl Hanser Verlag, München