Polymer Composites: from Nano- to Macroscale EP/MWCNT 0. 05 wt. %6 NTO. 25 wt%o EP/MWCNT 0.50 wt, 5b EP/MWCNT 0.75 wt. Temperature (C 0000 EP/0.05 wt. So MWCNT-NH, P/O 10 wt% MWCNT-NH e EP/O15 wt% MWCNT-NH2 EP/0.25 wt% MWCNT-NH, EP/O50 wt R MWCNT-NH, 一EP/.75wt% MWCNT-NH 120-100-806040-200204060 100120140 Figure 17. Complex modulus and loss facto notube/epoxy nanocomposites with(a) non-functionalized nanotubes and (b)am nalized nanotubes 18 the chemical functionalization of carbon nanotubes on the interfacial adhesion and the resulting mechanical reinforcement( Figure 20 4.6 Electrical Properties Carbon nanotubes dispersed as conductive fillers in an epoxy matrix result in electrical properties which can be compared to those obtained using an optimized
18 Polymer Composites: from Nano- to Macroscale - EPJMWCNT OS 4* EP/MWCNT 0.: - EPNWCNT 0.: -lP -100 -80 60 -40 -20 0 20 40 60 80 100 120 140 Temperature (OC) (X3 8 u 0,l 3 "l I; 4 0.01 -lP -100 -80 -BO -40 -20 0 20 40 60 80 100 120 140 Temperature (OC) Figure 17. Complex modulus and loss factor of nanotubelepoxy nanocomposites with (a) non-functionalized nanotubes and (b) amino-functionalized nanotubes." the chemical functionalization of carbon nanotubes on the interfacial adhesion and the resulting mechanical reinforcement (Figure 20). 4.6 Electrical Properties Carbon nanotubes dispersed as conductive fillers in an epoxy matrix result in electrical properties which can be compared to those obtained using an optimized
Chapter 1: Carbon Nanotube-Reinforced polymers P/MWCNT 0.05 wt% EP/MWCNT0.50 wt %o EP/MWCNT 0.75 wt %o 506070 Temperature (C) 400- EP/0.05 wt. 9 MWCNT-NH 300·EP050 wt. MWCNT-NH2 EP/0. 75 wt. MWCNT-NH Temperature(C) Figure 18 Loss modulus of nanotube/epoxy nanocomposites with (a) non-functionalized nanotubes and(b)amino-functionalized nanotubes. 8 process with carbon black. 9 Sufficient matrix conductivity for anti-static applications can be achieved at lower filler concentrations using carbon nanotubes instead of carbon black, CNT reduce the percolation threshold to below 0.04 wt. (Figure 21), and increase the overall conductivity achieved. At these low filler fractions, neither the processing behavior of the matrix nor the surface finish of
Chapter 1: Carbon Nanotube-Reinforced Polymers h EPIMWCNT 0.05 wt.% EPIMWCNT 0.25 wt.% A EPIMWCNT 0 50 wt.% r EPIMWCNT 0 75 wt.% 20 30 40 50 60 70 80 90 100 Temperature ("C) Temperature ("C) Figure 18. Loss modulus of nanotubelepoxy nanocomposites with (a) non-functionalized nanotubes and (b) amino-functionalized nanotubes.18 process with carbon black.'g Sufficient matrix conductivity for anti-static applications can be achieved at lower filler concentrations using carbon nanotubes instead of carbon black. CNT reduce the percolation threshold to below 0.04 wt.% (Figure 21), and increase the overall conductivity achieved. At these low filler fractions, neither the processing behavior of the matrix nor the surface finish of
Polymer Composites: from Nano- to Macroscale MWCNT-Glass transition temperature 6 72 000.10.20.3040.50.60.70.8 Nanotube content(wt %) Figure 19. Glass transition temperature(from DMTA)as a function of nanotube content. 4 Epoxy/0.15 wt% MWCNT-NH 5 Epoxy/0. 25 wt% MWCNT-NI 5678 Strain(%) Figure 20 Stress-strain curves of functionalized carbon nanotubes in an e epoxy matrix to modify both the electrical and the mechanical properties of an insuopportunities the samples are adversely affected. Carbon nanotubes may offer nev ting matrIx
Polymer Composites: from Nano- to Macroscale Nanotube content (wt.%) 84 ' Figure 19. Glass transition temperature (from DMTA) as a function of nanotube content." r Epoxy - Glass transition temperature A EpoxyIMWCNT-NH, - Glass transition temperature 0 EpoxyIMWCNT - Glass transition temperature 012345678 Strain (%) Figure 20. Stress-strain curves of functionalized carbon nanotubes in an epoxy matrix. 80 - the samples are adversely affected.' Carbon nanotubes may offer new opportunities to modify both the electrical and the mechanical properties of an insulating matrix. *.*' /' *.-=- C..C 76 - ,/' , .-- ,- 0
Chapter 1: Carbon Nanotube-Reinforced Polymers 10° carbon n- cataly -Carbon black Carbon black copper chloride 10 lytically grown carbon nanotubes and carbon black as a function of the filler volume content. Conclusio Compared to bulk materials, fiber-reinforced composites have already proven to exhibit superior properties in numerous applications. However, various desired combinations of properties, e.g, strong reinforcing effects at high optical transparency combined with electrical conductivity or reinforced micro-injection molded parts, cannot be achieved by traditional Sites. The further improvement of the fracture toughness of resin matrices is another important task. the potential to fill this existing gap The excellent mechanical properties of carbon nanotubes and their high ectrical and thermal conductivity make them ideal candidates for a wide range of applications where long carbon fiber-reinforced polymers cannot be employed The present chapter shows the potential of the CNt as nanofillers in polymers, but also the need of further development for the achievement of optimal dispersion and orientation in order to attain the best possible properties CNT are capable of reinforcing polymers, making them electrically conductive and thermally more stable already at low volume fractions 6 Acknowledgements The support of the German Scientific Foundation ( DFG)SFB 371-TPC and Schu 928/8 and of the European Commission(Scientific-NetworkCNT Net" Contract N: G5RT-CT-2001-050206)is gratefully acknowledged
Chapter I: Carbon Nanotube-Reinforced Polymers lo0 lo-' - a 10-3 c .g .- * 104 3 -Carbon black 8 lo4 3 Carbon black + i o-~ 0.01 0.1 1 10 Log volume fraction (%) Figure 21. Comparative log-log plot of the conductivity of nanocomposites containing catalytically grown carbon nanotubes and carbon black as a function of the filler volume content.' 5 Conclusions Compared to bulk materials, fiber-reinforced composites have already proven to exhibit superior properties in numerous applications. However, various desired combinations of properties, e.g., strong reinforcing effects at high optical transparency combined with electrical conductivity or reinforced micro-injection molded parts, cannot be achieved by traditional composites. The further improvement of the fracture toughness of resin matrices is another important task. Nanocomposites possess the potential to fill this existing gap. The excellent mechanical properties of carbon nanotubes and their high electrical and thermal conductivity make them ideal candidates for a wide range of applications where long carbon fiber-reinforced polymers cannot be employed. The present chapter shows the potential of the CNT as nanofillers in polymers, but also the need of further development for the achievement of optimal dispersion and orientation in order to attain the best possible properties. CNT are capable of reinforcing polymers, making them electrically conductive and thermally more stable already at low volume fractions. 6 Acknowledgements The support of the German Scientific Foundation (DFG) SFB 371-TP C9 and Schu 92818 and of the European Commission (Scientific-Network "CNTNet"; Contract No: G5RT-CT-2001-050206) is gratefully acknowledged
Polymer Composites: from Nano- to Macroscale References J. Sandler, M.S. P. Shaffer, T Prasse, W. Bauhofer, K. Schulte, A H. windle(1999 Development of a dispersion process for carbon nanotubes in an epoxy matrix and the resulting electrical properties, Polymer 40, 5967. T. Prasse, A. Ivankov, J. Sandler, K. Schulte, w. Bauhofer (2001)Imaging of conductive filler networks in heterogeneous materials by scanning Kelvin micro scopy, J. Appl. Polym. Sci. 82, 3381 [3] G. Overney, W. Zong, D. Tomanek(1993)Structural rigidity and low frequency vibrational models of long carbon tubules, Z Physik D 27, 93 R. S. Ruoff, D. C. Lorents(1995)Mechanical and thermal properties of carbon nanotubes. Carbon 33. 925 H D. Wagner, O Lourie( 1998)Evaluation of Young,s modulus of carbon nanotubes by [6] H D. Wagner, O Lourie, Y. Feldmann, R Tenne( 1998)Stress-induced fragmentation of multiwall carbon nanotubes in a polymer matrix, Appl. Phys. Letf. 72, 188 http://www.cnanotech.com/4-0_about.cfm [8]http://www5.dsm.com.en_us/html/home/dsm_home.pl F. H. Gojny, J. Nastalczyk, K. Schulte, Z. Roslaniec (2003)Surface-modified nanotubes in CNT/epoxy-nanocomposites, Chem. Phys. Lett. 370, 820 D B Mawhinney, V Naumenko, A Kuznetsova, J. T. Yates Jr (2000)Infrared spectral evidence of the etching of carbon nanotubes: ozone oxidation at 298 K, Am. Chem. Soc. 122, 2382 [11] Y Chen, R C Haddon, S Fang, A M. Rao, P C Eklund, W.H. Lee, E C Dickey E. A Grulke, J C. Pendergrass, A Chavan, B. E. Haley, R S Smalley(1998) Chemical attachment of organic functional groups to single walled carbon nanotube material, Mater. Res. 13, 2423 [12] L. Zimmerman, R. K Bradley, C. B Huffman, R. H, Hauge, J. L Margrave (2000)Gas-phase purification of single-wall carbon nanotubes, Chem. Mater [13] K. Hernadi, A Siska, L. Thien-Nga, L. Forro, I Kiricsi(2001)Reactivity of different ds of carbon during oxidative purification of catalytically prepared ca nanotubes Solid State Ionics 141-142. 203 [14] L. w. Chiang, B. E Brinson, R E. Smalley, J. L Margrave, R. H Hauge(2001 Purification and characterization of single wall carbon nanotubes, J. Phys. Chem. B105,1157 [15] S.A. Curran, P. M. Ajayan, W.J. Blau, D. L. Carrol, J N Coleman, A. B Dalton, A P. Davey, A. Drury, B. McCarthy, S Maier, A Stevens(1998)Composite from poly(m-phenylenevinylene-co-2, 5-dioctozy-p-phenylenevinylene) and carbon nanotubes: a novel material for molecular optoelectronics, Adv. Mater: 10, 1091 [16] B. McCarthy, J N. Coleman, S.A. Curran, A B. Dalton, A P. Davey, Z. Konya, A Fonseca, J. B. Nagy, w. J. Blau (2000)Observation of site selective binding in a polymer nanotube composite, J. Mater Sci. Lett. 12, 2239 [17 S.J.V. Frankland, A Calgar, D. V. Brenner, M. Griebel(2002)Molecular simulation of the influence of chemical cross-links on the shear-strength of carbon nanotube- polymer interfaces, J Phys. Chem. B 106, 3046
Polymer Composites: from Nano- to Macroscale References J. Sandler, M. S. P. Shaffer, T. Prasse, W. Bauhofer, K. Schulte, A. H. Windle (1999) Development of a dispersion process for carbon nanotubes in an epoxy matrix and the resulting electrical properties, Polymer 40,5967. T. Prasse, A. Ivankov, J. Sandler, K. Schulte, W. Bauhofer (2001) Imaging of conductive filler networks in heterogeneous materials by scanning Kelvin microscopy, J. Appl. Polym. Sci. 82,3381. G. Overney, W. Zong, D. Tominek (1993) Structural rigidity and low frequency vibrational models of long carbon tubules, Z. Physik D 27,93. R. S. Ruoff, D. C. Lorents (1995) Mechanical and thermal properties of carbon nanotubes, Carbon 33,925. H. D. Wagner, 0. Lourie (1998) Evaluation of Young's modulus of carbon nanotubes by micro-Raman spectroscopy, J. Mater. Res. 13,2418. H. D. Wagner, 0. Lourie, Y. Feldmann, R.Tenne (1998) Stress-induced fragmentation of multiwall carbon nanotubes in a polymer matrix, Appl. Phys. Lett. 72, 188. http:/lwww.cnanotech.com/4-0-about.cfm http://www5.dsm.com.enhttp://www5.dsm.com.en_US/html/home/dsm_US/html/homeldsm~home.pl F. H. Gojny, J. Nastalczyk, K. Schulte, Z. Roslaniec (2003) Surface-modified nanotubes in CNTlepoxy-nanocomposites, Chem. Phys. Lett. 370,820. D. B. Mawhinney, V. Naumenko, A. Kuznetsova, J. T. Yates Jr. (2000) Infrared spectral evidence of the etching of carbon nanotubes: ozone oxidation at 298 K, J. Am. Chem. Soc. 122,2382. Y. Chen, R. C. Haddon, S. Fang, A. M. Rao, P. C. Eklund, W. H. Lee, E. C. Dickey, E. A. Grulke, J. C. Pendergrass, A. Chavan, B. E. Haley, R. S. Smalley (1998) Chemical attachment of organic functional groups to single walled carbon nanotube material, J. Mate,: Res. 13,2423. J. L. Zimmerman, R. K. Bradley, C. B. Huffman, R. H. Hauge, J. L. Margrave (2000) Gas-phase purification of single-wall carbon nanotubes, Chem. Mater. 12, 1361. K. Hernadi, A. Siska, L. ThiEn-Nga, L. Forr6, I. Kiricsi (2001) Reactivity of different kinds of carbon during oxidative purification of catalytically prepared carbon nanotubes, Solid State Ionics 141-142,203. I. W. Chiang, B. E. Brinson, R. E. Smalley, J. L. Margrave, R. H. Hauge (2001) Purification and characterization of single wall carbon nanotubes, J. Phys. Chem. B 105, 1157. S. A. Curran, P. M. Ajayan, W. J. Blau, D. L. Carrol, J. N. Coleman, A. B. Dalton, A. P. Davey, A. Drury, B. McCarthy, S. Maier, A. Stevens (1998) Composite from poly(m-phenylenevinylene-co-2,5-dioctozy-p-phenylenevinylene) and carbon nanotubes: a novel material for molecular optoelectronics, Adv. Mater. 10, 1091. B. McCarthy, J. N. Coleman, S. A. Curran, A. B. Dalton, A. P. Davey, Z. Konya, A. Fonseca, J. B. Nagy, W. J. Blau (2000) Observation of site selective binding in a polymer nanotube composite, J. Mate,: Sci. Lett. 12,2239. S. J. V. Frankland, A. Calgar, D. V. Brenner, M. Griebel(2002) Molecular simulation of the influence of chemical cross-links on the shear-strength of carbon nanotubepolymer interfaces, J. Phys. Chem. B 106,3046