Mechanical and viscoelastic properties of epoxy nanocomposites reinforced with carbon nanotubes, nanoclay, and binary nanoparticles

2017 ◽  
Vol 36 (9) ◽  
pp. 667-684 ◽  
Author(s):  
Mahesh Hosur ◽  
Tanjheel H Mahdi ◽  
Mohammad E Islam ◽  
S Jeelani

Mechanical and viscoelastic properties of polymer nanocomposites reinforced with carboxyl functionalized multiwalled carbon nanotubes (COOH-MWCNT), montmorillonite nanoclays (MMT), and MWCNT/MMT binary nanoparticle were investigated. In this study, 0.3 wt% of COOH-MWCNT, 2 wt% of MMT, and 0.1 wt% COOH-MWCNT/2 wt% MMT binary nanoparticles by weight of epoxy were incorporated to modify SC-15 epoxy resin system. Nanocomposites were subjected to flexural test, dynamic mechanical, and thermomechanical analyses. Morphological study was conducted with microscopy. Addition of each of the nanoparticles in epoxy showed significant improvement in the mechanical and viscoelastic properties compared to those of the control ones. However, best results were obtained by addition of 0.1% MWCNT/2% MMT binary nanoparticles in epoxy. Nanocomposites modified with binary nanoparticles exhibited about 20% increase in storage modulus as well as 25℃ increase in the glass transition temperature. Flexural modulus for binary nanoparticle modified composites depicted about 30% improvement compared to the control ones. Thus, improvement of mechanical and viscoelastic properties was achieved by incorporating binary nanoparticles to epoxy nanocomposites. The increase in properties was attributed to the synergistic effect of MWCNTs and nanoclay in chemically interacting with each other and epoxy resin as well as in arresting and delaying the crack growth, once initiated.

Author(s):  
Tanjheel H. Mahdi ◽  
Mohammad E. Islam ◽  
Mahesh V. Hosur ◽  
Alfred Tcherbi-Narteh ◽  
S. Jeelani

Mechanical and viscoelastic properties of polymer nanocomposites reinforced with carboxyl functionalized multiwalled carbon nanotubes (COOH-MWCNT), montmorillonite nanoclays (MMT) and MWCNT/MMT binary nanoparticle were investigated. In this study, 0.3 wt. % of COOH-MWCNT, 2 wt. % of MMT and 0.1 wt. % COOH-MWCNT/2 wt. % MMT binary nanoparticles by weight of epoxy were incorporated to modify SC-15 epoxy resin system. The nanocomposites were subjected to flexure test, dynamic mechanical and thermomechanical analyses. Morphological study was conducted with scanning electron microscope. Addition of each of the nanoparticles in epoxy showed significant improvement in mechanical and viscoelastic properties compared to those of control ones. But, best results were obtained for addition of 0.1% MWCNT/2% MMT binary nanoparticles in epoxy. Nanocomposites modified with binary nanoparticles exhibited about 20% increase in storage modulus as well as 25° C increase in glass transition temperature. Flexural modulus for binary nanoparticle modified composites depicted about 30% improvement compared to control ones. Thus, improvement of mechanical and viscoelastic properties was achieved by incorporating binary nanoparticles to epoxy nanocomposites. The increase in properties was attributed to synergistic effect of MWCNTs and nanoclay in chemically interacting with each other and epoxy resin as well as in arresting and delaying the crack growth once initiated.


2020 ◽  
pp. 096739112093523
Author(s):  
Mohammad Ebrahim Karkhanehchin ◽  
Morteza Maghrebi ◽  
Majid Baniadam ◽  
Ali Dashti ◽  
Maryam Mokhtarifar

The aim of this study was to produce carbon nanotubes (CNTs)/polymer composite fibers by wet spinning without any solvent. The functionalized multiwalled-carbon nanotubes (F-MWNTs)/epoxy resin was synthesized by in situ polymerization method. Epoxy resin, F-MWNTs, and curing agent were mixed and injected by a syringe pump. The effects of operating parameters including the percentage of CNTs and the extrusion velocity of the syringe pump on the dispersion and alignment of F-MWNTs in the cross-section of F-MWNTs/polymer composite fibers were investigated. The composite fibers were characterized by tensile strength analysis, scanning electron microscopy (SEM), and electrical conductivity analysis. The experimental results showed that a decrease (30 ml/h to 15 ml/h) in extrusion velocity increased the electrical conductivity of composite fibers by more than 3%. This behavior was attributed to the higher alignment of F-MWNTs and improved conducting pathways along the composite fiber axis, as observed by SEM. In addition, by reducing extrusion velocity (30 ml/h to 15 ml/h), the tensile strength of composite fibers was enhanced just over twofold due to the better arrangement of CNTs which can be attributed to the further retention time of composite fibers and the pressure of the walled-needle. Moreover, the higher the processing time of spinning, the lower electrical conductivity of the fibers is which might be due to the higher coagulation of fibers.


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