Multi-walled carbon nanotubes (MWCNTs) modified by concentrated sulfuric acid/nitric acid (H2SO4/HNO3) and silane coupling agent (γ-aminopropyltriethoxy silane, KH550) was studied by Fourier transform infrared spectrometry (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effect of modified MWCNTs on crystallization behaviour and mechanical properties of low density polyethylene (LDPE)/polyolefin elastomer (POE)/MWCNTs composites were investigated. The results revealed that the crystallinity of composites increased with the addition of the raw MWCNTs and MWCNTs which were modified by H2SO4/HNO3 and KH550. The MWCNTs treated by H2SO4/HNO3 had a better dispersion in matrix than raw MWCNTs and it was beneficial to tensile strength. Further modification by KH550 on H2SO4/HNO3 treated MWCNTs could improve the dispersion of MWCNTs in matrix and interfacial adhesion between MWCNTs and matrix, leading to the tensile strength increased by 35.5 % compared to LDPE/POE composite with raw MWCNTs, and modulus at 100% of composites also increased.
References
1.
AjayanP.M., StephanO., ColliexC., and TrauthD., Aligned carbon nanotube arrays formed by cutting a polymer resin–nanotube composite, Science, 265 (1994), 1212–1214.
2.
IsayevA.I., KumarR., and LewisT.M., Ultrasound assisted twin screw extrusion of polymer-nanocomposites containing carbon nanotubes, Polymer, 50 (2009), 250–260.
3.
LeeW.J., LeeS.E., and KimC.G., The mechanical properties of MWNT/PMMA nanocomposites fabricated by modified injection molding, Composite Structures, 76 (2006), 406–410.
4.
ZhouZ., WangS., LuL., ZhangY., and ZhangY., Functionalization of multi-wall carbon nanotubes with silane and its reinforcement on polypropylene composites, Composites Science and Technology, 68 (2008), 1727–1733.
5.
ZouW., DuZ.J., LiuY.X., YangX.P., LiH.Q., and ZhangC., Functionalization of MWNTs using polyacryloyl chloride and the properties of CNT-epoxy matrix nanocomposites, Composites Science and Technology, 68 (2008), 3259–3264.
6.
SaitoT., MatsushigeK., and TanakaK., Chemical treatment and modification of multi-walled carbon nanotubes, Physica B: Condensed matter, 323 (2002), 280–283.
7.
BikiarisD., VassiliouA., ChrissafisK., ParaskevopoulosK.M., JannakoudakisA., and DocoslisA., Effect of acid treated multi-walled carbon nanotubes on the mechanical, permeability, thermal properties and thermo-oxidative stability of isotactic polypropylene, Polymer Degradation and Stability, 93 (2008), 952–967.
8.
MengH., SuiG.X., FangP.F., and YangR., Effects of acid- and diamine-modified MWNTs on the mechanical properties and crystallization behavior of polyamide 6, Polymer, 49 (2008), 610–620.
9.
ZhuB.K., XieS.H., XuZ.K., and XuY.Y., Preparation and properties of the polyimide/multi-walled carbon nanotubes (MWNTs) nanocomposites, Composites Science and Technology, 66 (2006), 548–554.
10.
ShokoohiS., ArefazarA., and KhosrokhavarR., Silane coupling agents in polymer-based reinforced composites: A review, Journal of Reinforced Plastics and Composites, 27 (2008), 473–485.
11.
JiangM.J., DangZ.M., and XuH.P., Enhanced electrical conductivity in chemically modified carbon nanotube/methylvinyl silicone rubber nanocomposite, European Polymer Journal, 43 (2007), 4924–4930.
12.
YingJ.R., LiuS.P., GuoF., ZhouX.P., and XieX.L., Non-isothermal crystallization and crystalline structure of PP/POE blends, Journal of Thermal Analysis and Calorimetry, 91 (2008), 723–731.
13.
XieB.H., ShenY.X., LiZ.M., YangW., FengJ.M., and YangM.B., Fracture behavior of polypropylene/POE blends with different mixed ratios, Acta Polymerica Sinica, 2 (2006), 335–339.
14.
KeQ.Q., HuangX.Y., WeiP., WangG.L., and JiangP.K., Thermal, mechanical, and dielectric behaviors of crosslinked linear low density polyethylene/polyolefin elastomers blends, Journal of Applied Polymer Science, 104 (2007), 1920–1927.
15.
DangtungeeR., DesaiS.S., TantayanonS., and SupapholP., Melt rheology and extrudate swell of low-density polyethylene/ethylene-octene copolymer blends, Polymer Testing, 25 (2006), 888–895.
16.
BaghaeiB., JafariS.H., KhonakdarH.A., RezaeianI., As'HabiL., and AhmadianS., Interfacially compatibilized LDPE/POE blends reinforced with nanoclay: Investigation of morphology, rheology and dynamic mechanical properties, Polymer Bulletin, 62 (2009), 255–270.
17.
LingQ., SunJ., ZhaoQ., and ZhouQ., Microwave absorbing properties of linear low density polyethylene/ethylene-octene copolymer composites filled with short carbon fiber, Materials Science and Engineering: B, 162 (2009), 162–166.
18.
MolyK.A., RaduschH.J., AndroshR., BhagawanS.S., and ThomasS., Nonisothermal crystallisation, melting behavior and wide angle X-ray scattering investigations on linear low density polyethylene (LLDPE)/ethylene vinyl acetate (EVA) blends: effects of compatibilisation and dynamic crosslinking, European Polymer Journal, 41 (2005), 1410–1419.
19.
BrandrupJ., and ImmergutE.H., Polymer handbook.Wiley & Sons Inc, New York (1999).
20.
RamanathanT., FisherF.T., RuoffR.S., and BrinsonL.C., Amino-functionalized carbon nanotubes for binding to polymers and biological systems, Chemistry of Materials, 17 (2005), 1290–1295.
21.
ZhangJ., ZouH., QingQ., YangY., LiQ., LiuZ., GuoX., and DuZ., Effect of chemical oxidation on the structure of single-walled carbon nanotubes, Journal of Physical Chemistry B, 107 (2003), 3712–3718.
22.
GoyanesS., RubioloG.R., SalazarA., JimenoA., CorcueraM.A., and MondragonI., Carboxylation treatment of multiwalled carbon nanotubes monitored by infrared and ultraviolet spectroscopies and scanning probe microscopy, Diamond and Related Materials, 16 (2007), 412–417.
23.
EndoM., TakeuchiK., HiraokaT., FurutaT., KasaiT., SunX., KiangC.H., and DresselhausM.S., Stacking nature of graphene layers in carbon nanotubes and nanofibres, Journal of Physics and Chemistry of Solids, 58 (1997), 1707–1712.
