Thermo-mechanical properties of epoxy nanocomposites incorporating amino acid and acid functionalized multi-walled carbon nanotubes

Abstract

In this study, multi-walled carbon nanotubes (MWCNTs) were functionalized by both sulfuric/nitric acids and amino acids to form COOH and NH2/COOH/OH groups on their surface, respectively. The functionalized MWCNTs were characterized by Fourier Transform Infrared Spectroscopy, titration test, thermal gravimetric analysis, and solvent stability test. The results revealed that in each method, the functional groups were successfully attached to the surface of nanotubes. Acid treatment grafted more oxygen-containing groups compared to commercial carboxylated MWCNTs. The amino acid functionalized MWCNTs indicated improved stability in different solvents compared to raw and acid treated MWCNTs. These functionalized MWCNTs were incorporated into epoxy resin and the properties of the nanocomposites were evaluated by scanning electron microscopy, tensile test, dynamic mechanical thermal analysis, differential scanning calorimetry, and thermogravimetric analysis. The morphology of the nanocomposites revealed that acid and amino acid treated samples had better interaction with the epoxy resin. Compared to epoxy sample contained raw MWCNT (control) and commercial carboxylated MWCNTs, the addition of functionalized MWCNTs to the epoxy resin improved the tensile strength by 39% and 25% (for acid treated) and 46% and 33% (for amino acid treated), respectively. The best tensile properties for acid and amino acid treated samples were reached by MWCNTs acid treated at 110℃ for 15 min and MWCNTs treated in a 50 g/L aqueous solution of amino acid, respectively. Storage modulus of the epoxy samples which contained acid and amino acid treated MWCNTs were 1560 and 1900 MPa, respectively. The glass rubber transition temperature (T_g) of the epoxy samples containing acid and amino acid treated nanotubes were increased by 1.1℃ and 5.9℃, respectively, compared to the control sample. Therefore, based on these mechanical properties, the epoxy samples containing nanotubes functionalized by amino acid exhibited the highest performance in the epoxy nanocomposite. Incorporating acid and amino acid treated MWCNTs accelerated the curing process of epoxy where the curing temperature decreased by 9.1℃ and 13.3℃, respectively. Because of the reaction between amine groups grafted on MWCNTs in the amino acid treatment and epoxide groups of the epoxy resin, this acceleration was more significant in the case of amino acid sample. Note that addition of functionalized MWCNTs to epoxy resin did not lead to increased thermal stability.

Keywords

Epoxy nanocomposite multi-walled carbon nanotube surface functionalization carboxyl group amino acid

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References

Kroto

Heath

O’Brien

, et al. C60: Buckminsterfullerene. Nature 1985; 318: 162–163.

Reich

Thomsen

Maultzsch

. Carbon nanotubes: Basic concepts and physical properties, New York: Wiley-VCH, 2004.

Qian

Wagner

Liu

, et al. Mechanics of carbon nanotubes. Appl Mech Rev 2002; 55: 495–533.

Small

Shi

Kim

. Mesoscopic thermal and thermoelectric measurements of individual carbon nanotubes. Solid State Commun 2003; 127: 181–186.

Grossiord

Loos

Regev

, et al. Toolbox for dispersing carbon nanotubes into polymers to get conductive nanocomposites. Chem Mater 2006; 18: 1089–1099.

Zhang

Dehghani-Sanij

Blackburn

. Carbon based conductive polymer composites. J Mater Sci 2007; 42: 3408–3418.

Han

Fina

. Thermal conductivity of carbon nanotubes and their polymer nanocomposites: A review. Prog Polym Sci 2011; 36: 914–944.

Thostenson

Ren

Chou

. Advances in the science and technology of carbon nanotubes and their composites: A review. Comput Sci Technol 2001; 61: 1899–1899.

Chang

Liu

, et al. Chemistry of carbon nanotubes in biomedical applications. J Mater Chem 2010; 20: 1036–1052.

10.

Coleman

Khan

Gunko

. Mechanical reinforcement of polymers using carbon nanotubes. Adv Mater 2006; 18: 689–706.

11.

Kim

Mai

. Engineered interfaces in fiber reinforced composites, Oxford: Elsevier, 1998, pp. 1–100.

12.

Cividanes

Simonetti

EAN

Moraes

, et al. Influence of carbon nanotubes on epoxy resin cure reaction using different techniques: A comprehensive review. Polym Eng Sci 2014; 54(11): 2461–2469.

13.

Xie

Mai

Zhou

. Dispersion and alignment of carbon nanotubes in polymer. Mater Sci Eng 2005; 49: 89–112.

14.

Siddiqui

Marom

, et al. Dispersion and functionalization of carbon nanotubes for polymer-based nanocomposites: A review. Compos Part A-Appl Sci Manuf 2010; 41: 1345–1367.

15.

Shieh

Liu

, et al. Effects of polarity and pH on the solubility of acid-treated carbon nanotubes in different media. Carbon 2007; 45: 1880–1890.

16.

Osorio

Silveira

ICL

Bueno

, et al. H₂SO₄/HNO₃/HCl functionalization and its effect on dispersion of carbon nanotubes in aqueous media. Appl Surf Sci 2008; 255: 2485–2489.

17.

Najafi

Kim

Han

, et al. UV-ozone treatment of multi-walled carbon nanotubes for enhanced organic solvent dispersion. Colloids Surf A 2006; 284–285: 373–378.

18.

Bikiaris

Vassiliou

Chrissafis

, et al. Effect of acid treated multi-walled carbon nanotubes on the mechanical, permeability, thermal properties and thermo-oxidative stability of isotactic polypropylene. Polym Degrad Stab 2008; 93: 952–967.

19.

Saito

Matsushige

Tanaka

. Chemical treatment and modification of multi-walled carbon nanotubes. Physica B 2002; 323: 280–283.

20.

Pumera

Šmíd

Veltruská

. Influence of nitric acid treatment of carbon nanotubes on their physico-chemical properties. J Nanosci Nanotechnol 2009; 9: 2671–2676.

21.

Kim

, et al. A comparative study on properties of multi-walled carbon nanotubes (MWCNTs) modified with acids and oxyfluorination. J Fluorine Chem 2007; 128: 60–64.

22.

Kwon

Kim

. Preparation and properties of acid-treated multiwalled carbon nanotube/waterborne polyurethane nanocomposites. J Appl Polym Sci 2005; 96: 595–604.

23.

Zakharychev

Razov

Semchikov

, et al. The influence of functionalization time of carbon nanotube on the mechanical properties of the epoxy composites. J Compos Mater 2017; 51(12): 1693–1701.

24.

Avilés

Cauich-Rodríguez

Moo-Tah

, et al. Evaluation of mild acid oxidation treatments for MWCNT functionalization. Carbon 2009; 47(13): 2970–2975.

25.

Kim

Rhee

Park

, et al. Effects of silane-modified carbon nanotubes on flexural and fracture behaviors of carbon nanotube-modified epoxy/basalt composites. Composites Part B 2012; 43: 2298–2302.

26.

Chen

Wang

Lina

, et al. Mechanical and thermal properties of epoxy nanocomposites reinforced with amino functionalized multi-walled carbon nanotubes. Mater Sci Eng: Part A 2008; 492: 236–242.

27.

Wang

Zhang

, et al. Adsorption and properties of aromatic amino acids on single-walled carbon nanotubes. Nanoscale 2012; 4(4): 46–53.

28.

Anversa

Piquini

. The effects of an explicit water environment on the interaction of a single wall carbon nanotube with amino acids: A theoretical study. Chem Phys Lett 2011; 51: 68–81.

29.

Piao

Liu

. Interaction of amino acids and single wall carbon nanotubes. J Phys Chem C 2012; 116(2): 1724–1731.

30.

Zhou

. Probing carbon nanotube–amino acid interactions in aqueous solution with molecular dynamics simulations. Carbon 2014; 78: 500–509.

31.

Mallakpour

Zadehnazari

. A facile, efficient, and rapid covalent functionalization of multi-walled carbon nanotubes with natural amino acids under microwave irradiation. Prog Org Coat 2014; 77: 679–684.

32.

Mallakpour

Zadehnazari

. Effect of amino acid-functionalization on the interfacial adhesion and behavior of multi-walled carbon nanotubes/poly (amide-imide) nanocomposites containing thiazole side unit. J Polym Res 2013; 20: 192–192.

33.

Mallakpour

Zadehnazari

. Functionalization of multi-wall carbon nanotubes with amino acid and its influence on the properties of thiadiazol bearing poly(amide-thioester-imide) composites. Synth Met 2013; 169: 1–11.

34.

Coates J. Interpretation of infrared spectra, a practical approach. In: Meyers RA (ed.) Encyclopedia of analytical chemistry. New York: Wiley, 2000, pp.10815–10837.

35.

Pourfayaz

Mortazavi

Khodadadi

A-A

, et al. Comparison of effects of plasma and acid functionalizations on structure and electrical property of multi-wall carbon nanotubes. Appl Surf Sci 2014; 295: 66–70.

36.

Datsyuk

Kalyva

Papagelis

, et al. Chemical oxidation of multiwalled carbon nanotubes. Carbon 2008; 46: 833–840.

37.

Huang

Gao

Pan

, et al. Effective thermal conductivity of epoxy matrix filled with poly (ethyleneimine) functionalized carbon nanotubes. Compos Sci Technol 2014; 95: 16–20.

38.

Martin-Gallego

Bernal

Hernandez

, et al. Comparison of filler percolation and mechanical properties in graphene and carbon nanotubes filled epoxy nanocomposites. Eur Polym J 2013; 49: 1347–1353.

39.

Gojny

Schulte

. Functionalization effect on the thermo-mechanical behavior of multi-wall carbon nanotube/epoxy-composites. Compos Sci Technol 2004; 64: 2303–2308.

40.

Cheng Ma

Kim

J-K

Tang

. Effects of silane functionalization on the properties of carbon nanotube/epoxy nanocomposites. Compos Sci Technol 2007; 67: 2965–2972.

41.

Shabestari

Kalali

González

, et al. Effect of nitrogen and oxygen doped carbon nanotubes on flammability of epoxy nanocomposites. Carbon 2017; 121: 193–200.

42.

Ray

Abdel-Magid

. Thermal behavior of single-walled carbon nanotube polymer–matrix composites. Composites Part A 2006; 37: 114–121.