Viscoelastic properties and determination of free volume fraction of multi-walled carbon nanotube/epoxy composite using dynamic mechanical thermal analysis

2012 ◽  
Vol 36 ◽  
pp. 408-414 ◽  
Author(s):  
Arash Montazeri ◽  
Khalil Pourshamsian ◽  
Mehran Riazian
Keyword(s):  
Thermal Analysis ◽  
Carbon Nanotube ◽  
Free Volume ◽  
Dynamic Mechanical Thermal Analysis ◽  
Viscoelastic Properties ◽  
Volume Fraction ◽  
Epoxy Composite ◽  
Free Volume Fraction ◽  
Multi Walled Carbon Nanotube

Viscoelastic Properties of Multi Walled Carbon Nanotube/Epoxy Composites at the Different Nanotube Content

2011 ◽  
Vol 13 ◽  
pp. 33-39 ◽  
Author(s):  
Arash Montazeri ◽  
Alireza Khavandi ◽  
Jafar Javadpour ◽  
Abbas Tcharkhtchi
Keyword(s):  
Carbon Nanotube ◽  
Viscoelastic Properties ◽  
Epoxy Composite ◽  
Viscoelastic Behavior ◽  
Molding Process ◽  
Cole Diagram ◽  
Multi Walled Carbon Nanotube ◽  
Viscoelastic Modeling ◽  
Good Agreement ◽  
Properties Of Composites

The viscoelastic properties of composites multi walled carbon nanotube / epoxy at different weight fractions (0.1, 0.5 and 1wt %) were evaluated by performing dynamic mechanical thermal analysis (DMTA) test. The MWCNT/ epoxy composite were fabricated by sonication and a cast molding process. The results showed that addition of nanotubes to epoxy had a significant effect on the viscoelastic properties. However, the use of 0.5wt% increased the viscoelastic properties more significantly. Concerning viscoelastic modeling, the COLE-COLE diagram has been plotted by the result of DMTA tests. These results show a good agreement between the Perez model and the viscoelastic behavior of the composite.

scholarly journals Viscoelastic Properties of Polypropylene Reinforced with Mica in and Transition Zones

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
S. Farzaneh ◽  
A. Tcharkhtchi
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Free Volume ◽  
Viscoelastic Properties ◽  
Volume Fraction ◽  
Loss Modulus ◽  
Glassy State ◽  
Transition Zones ◽  
Wlf Equation ◽  
Free Volume Fraction

The viscoelastic properties of mica-reinforced polypropylene (PP) was studied in temperature range between −30°C and 120°C. WLF equation permits determining the free volume fraction in and transitions regions. It was shown that the value of this parameter is lower for transition, indicating that the free volume and thermal expansion of region is more than that of region. At a 40% loading level, it was shown that the storage and loss modulus of mica-filled PP increases dramatically (in comparison with the pure polypropylene). The relative modulus does not change significantly at glassy state but it increases for the temperature higher than . It was also shown that mica does not affect the glass transition temperature but results in an increase in transition.

scholarly journals Effect of Terminal Groups on Thermomechanical and Dielectric Properties of Silica–Epoxy Composite Modified by Hyperbranched Polyester

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2451
Author(s):  
Jianwen Zhang ◽  
Dongwei Wang ◽  
Lujia Wang ◽  
Wanwan Zuo ◽  
Lijun Zhou ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Binding Energy ◽  
Epoxy Resin ◽  
Volume Fraction ◽  
Epoxy Composite ◽  
Mean Square Displacement ◽  
Mean Square ◽  
Hyperbranched Polyester ◽  
Free Volume Fraction

To study the effect of hyperbranched polyester with different kinds of terminal groups on the thermomechanical and dielectric properties of silica–epoxy resin composite, a molecular dynamics simulation method was utilized. Pure epoxy resin and four groups of silica–epoxy resin composites were established, where the silica surface was hydrogenated, grafted with silane coupling agents, and grafted with hyperbranched polyester with terminal carboxyl and terminal hydroxyl, respectively. Then the thermal conductivity, glass transition temperature, elastic modulus, dielectric constant, free volume fraction, mean square displacement, hydrogen bonds, and binding energy of the five models were calculated. The results showed that the hyperbranched polyester significantly improved the thermomechanical and dielectric properties of the silica–epoxy composites compared with other surface treatments, and the terminal groups had an obvious effect on the enhancement effect. Among them, epoxy composite modified by the hyperbranched polyester with terminal carboxy exhibited the best thermomechanical properties and lowest dielectric constant. Our analysis of the microstructure found that the two systems grafted with hyperbranched polyester had a smaller free volume fraction (FFV) and mean square displacement (MSD), and the larger number of hydrogen bonds and greater binding energy, indicating that weaker strength of molecular segments motion and stronger interfacial bonding between silica and epoxy resin matrix were the reasons for the enhancement of the thermomechanical and dielectric properties.

scholarly journals Shape and Temperature Expansion of Free Volume Holes in Some Cured Polybutadiene-Polyisoprene Rubber Blends

2021 ◽  
Vol 22 (3) ◽  
pp. 1436
Author(s):  
Giovanni Consolati ◽  
Eros Mossini ◽  
Dario Nichetti ◽  
Fiorenza Quasso ◽  
Giuseppe Maria Viola ◽  
...  
Keyword(s):  
Free Volume ◽  
Radial Direction ◽  
Volume Fraction ◽  
Spherical Shape ◽  
Suitable Model ◽  
Positron Annihilation Lifetime ◽  
Rubber Blends ◽  
Free Volume Fraction ◽  
Hole Model ◽  
Best Fit

The free volume fraction of a macromolecular structure can be assessed theoretically by using a suitable model; however, it can also be evaluated from experimental data obtained from dilatometry and positron annihilation lifetime spectra. In this second case, a regular geometry of the sub-nanometric cavities forming the free volume has to be assumed, although in fact they are irregularly shaped. The most popular approach is to guess spherical holes, which implies an isotropic growth of these last with temperature. In this work, we compared the free volume fraction, as obtained from experiments in a set of polybutadiene and polyisoprene cured rubbers and their blends, with the analogous quantity expected by using the lattice-hole model. The results allowed us to obtain insights on the approximate shape of the holes. Indeed, a cylindrical flattened geometry of the cavities produced a better agreement with the theory than the spherical shape. Furthermore, the best fit was obtained for holes that expanded preferentially in the radial direction, with a consequent decrease of the aspect ratio with temperature.

Fast and selective determination of phenazopyridine at a novel multi-walled carbon nanotube modified ZnCrFeO4 magnetic nanoparticle paste electrode

RSC Advances ◽  
2015 ◽  
Vol 5 (47) ◽  
pp. 37431-37439 ◽  
Author(s):  
M. Taei ◽  
F. Hasanpour ◽  
M. Movahedi ◽  
Sh. Mohammadian
Keyword(s):  
Carbon Nanotube ◽  
Carbon Paste Electrode ◽  
Magnetic Nanoparticle ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
Selective Determination ◽  
Multi Walled Carbon Nanotube ◽  
Electrocatalytic Determination ◽  
Paste Electrode

Fabrication process of MWCNTs/ZnCrFeO4 modified carbon paste electrode for electrocatalytic determination of phenazopyridine at the surface (a) CPE, and (b) MWCNTs/ZnCrFeO4 modified carbon paste electrode.

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