An Investigation of Carbon Nanotube Dispersion in Vinyl Ester Resin Using Mechanical, Thermal and Statistical Techniques

Author(s):  
Seyed Morteza Sabet ◽  
Hassan Mahfuz ◽  
Javad Hashemi

The inclusion of 0.25 and 0.5 wt.% functionalized multi-walled carbon nanotubes (MWCNTs) into a vinyl ester (VE) resin has been studied. To investigate the effect of carbon nanotubes (CNTs) dispersion, the sonication process has been performed under a variety of parameters including mixing time and sonication amplitude. Differential scanning calorimetry (DSC) and 3-point flexural testing methods have been employed to explore the thermo-mechanical properties of materials. Differential scanning calorimetry results show up to 13°C increase in the glass transition temperature (Tg) of the VE polymer by introducing 0.25 wt.% CNTs with a total sonication energy of 60 KJ. It is also established that the flexural modulus of the polymer can be improved up to 24%. An array indentation technique has been used to evaluate the hardness and elastic modulus variations in the regions of nanoparticle concentration. The resulting variations along the indentation array have been statistically studied using three-parameter Weibull distribution. Based on the resulting dispersion conditions, the optimum sonication parameters and nanoparticle concentration have been determined.

2010 ◽  
Vol 150-151 ◽  
pp. 1413-1416 ◽  
Author(s):  
Hong Yan Chen ◽  
Zhen Xing Kong ◽  
Ji Hui Wang

The cure kinetics of Derakane 411-350, a kind of vinyl ester resin, and its suspensions containing multi-walled carbon nanotubes( MWCNTs) were investigated via non-isothermal dynamic scanning calorimetry (DSC) measurements. The results showed that incorporation of MWCNTs into vinyl ester resin excessively reduces polymerization degree and crosslinking density of vinyl ester resin. For suppressing the negative effect caused by nanotubes, the higher temperature initiator combined with the initiator MEKP was used. Dynamic-mechanical Behavior testing was then carried out on the cured sample in order to relate the curing behavior of MWCNTs modified resin suspensions to mechanical response of their resulting nanocomposites. It was revealed that nanocomposites containing MWCNTs possessed larger storage modulus values as well as higher glass transition temperatures (Tg) as compared to those without MWCNTs after using mixed intiators system to improve the degree of cure.


2017 ◽  
Vol 25 (8) ◽  
pp. 611-620 ◽  
Author(s):  
Fabrizio Quadrini ◽  
Denise Bellisario ◽  
Loredana Santo ◽  
Felicia Stan ◽  
Fetecau Catalin

Multi-walled carbon-nanotubes (MWCNTs) were melt-mixed with three different thermoplastic matrices (polypropylene, PP, polycarbonate, PC, and thermoplastic polyurethane, TPU) to produce nanocomposites with three different filler contents (1, 3, and 5 wt.%). Initial nanocomposite blends (in the shape of pellets) were tested under differential scanning calorimetry to evaluate the effect of the melt mixing stage. Nanocomposite samples were produced by compression moulding in a laboratory-scale system, and were tested with quasi-static (bending, indentation), and dynamic mechanical tests as well as with friction tests. The results showed the effect of the filler content on the mechanical and functional properties of the nanocomposites. Compression moulding appeared to be a valuable solution to manufacture thermoplastic nanocomposites when injection moulding leads to loss of performance. MWCNT-filled thermoplastics could be used also for structural and functional uses despite, the present predominance of electrical applications.


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.


2011 ◽  
Vol 19 (9) ◽  
pp. 789-796 ◽  
Author(s):  
Mohammad Rajaei ◽  
Mohammad Hosain Beheshty ◽  
Mehran Hayaty

Glass/phenolic prepreg is one of the most applicable prepregs used for making composites for structural parts. To investigate the effective parameters on the processing and properties of these prepregs, thirty samples of glass/phenolic prepregs containing about 50 wt.% resins were prepared by using a resole type phenolic resin and satin glass fibre fabric. They were B-staged or pre-cured at 110 °C and 120 °C for different times from 15 to 50 min, to control the flow behaviour and tack properties. Tack and resin flow were characterized, in order to determine the conditions in which flow and tack properties are optimum. Results show that the levels of pre-cure or conversion were between 2% and 55%. The maximum tack was achieved at 5.3% conversion. Cure behaviour and rheological properties of these prepregs were studied by using differential scanning calorimetry and rheometry. An appropriate cure cycle is presented with the aid of these results. After curing the prepregs on the basis of this cure cycle, a flexural strength of 172.6 MPa and flexural modulus of 17 GPa were obtained.


2017 ◽  
Vol 730 ◽  
pp. 237-241
Author(s):  
Kittimon Jirakittidul ◽  
Krittaya Khrongsakun ◽  
Kannika Khongkhaw ◽  
Kusuman Nernplod

Polyurethanes (PU) have been widely used in many applications since their properties can be tailored as desire. In order to improve their electrical property, PU is incorporated with multi-walled carbon nanotubes (MWCNT). The effects of different mixing times and temperatures on selective dispersion of MWCNT in segmented PU were studied. Furthermore, segmented PU based on two different soft segments; i.e. polyester (PU-ester) and polyether (PU-ether), were used. PU/MWCNT nanocomposites were prepared by an internal mixer for 4-12 minutes at 190-210°C. FESEM, DSC and LCR meter were used to characterize morphology and thermal properties. It was found that MWCNT were dispersed in soft segment of PU-ether. Good MWCNT dispersion was able to achieve at high temperature with short mixing time or low temperature with long mixing time. On the other hand, PU-ester/MWCNT nanocomposites, MWCNT preferred to disperse in hard segment and could be dispersed well in PU-ester at low mixing temperature.


RSC Advances ◽  
2018 ◽  
Vol 8 (52) ◽  
pp. 29830-29839 ◽  
Author(s):  
Li Lu ◽  
Liao Xia ◽  
Hao Zengheng ◽  
Sheng Xingyue ◽  
Zhang Yi ◽  
...  

The cure kinetics of epoxy resin cured by D-EP, D-EP/CNT composites and D-EP/CNTs-H20 were investigated by non-isothermal differential scanning calorimetry (DSC).


2017 ◽  
Vol 730 ◽  
pp. 221-225
Author(s):  
Mohamed Bassyouni ◽  
Shereen M.S. Abdel-Hamid ◽  
Mohamed H. Abdel-Aziz ◽  
M.Sh. Zoromba

In this study, vinyl ester –Jute fiber biocomposites were prepared using vacuum-assisted resin infusion (VARI) process. Woven Jute fibers were used with mass fraction 0.68. Multi-walled carbon nanotubes (MWCNTs) are added to the resin with weight ratio 0.5: 99.5 to investigate the thermo-mechanical properties of bio-composites. Storage and loss modulus of vinyl ester bio-composites were investigated in the presence MWCNTs over a range of temperature (25 to 160 oC) to measure the capacity of bio-composite to store and dissipate energy. Damping properties of vinyl ester bio-composites were studied in terms of tan (d). Viscoelastic test using dynamic mechanical analysis (DMA) showed that the glass transition temperature increases with the addition of MWCNTs up to 112.4 oC. Addition of jute fiber reinforcements improves the storage modulus value of vinyl ester more than 65% at room temperature. Significant improvement in storage modulus was found in the presence of MWCNTs.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1459
Author(s):  
Agbelenko Koffi ◽  
Fayçal Mijiyawa ◽  
Demagna Koffi ◽  
Fouad Erchiqui ◽  
Lotfi Toubal

Wood–plastic composites have emerged and represent an alternative to conventional composites reinforced with synthetic carbon fiber or glass fiber–polymer. A wide variety of wood fibers are used in WPCs including birch fiber. Birch is a common hardwood tree that grows in cool areas such as the province of Quebec, Canada. The effect of the filler proportion on the mechanical properties, wettability, and thermal degradation of high-density polyethylene/birch fiber composite was studied. High-density polyethylene, birch fiber and maleic anhydride polyethylene as coupling agent were mixed and pressed to obtain test specimens. Tensile and flexural tests, scanning electron microscopy, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetry analysis and surface energy measurement were carried out. The tensile elastic modulus increased by 210% as the fiber content reached 50% by weight while the flexural modulus increased by 236%. The water droplet contact angle always exceeded 90°, meaning that the material remained hydrophobic. The thermal decomposition mass loss increased proportional with the percentage of fiber, which degraded at a lower temperature than the HDPE did. Both the storage modulus and the loss modulus increased with the proportion of fiber. Based on differential scanning calorimetry, neither the fiber proportion nor the coupling agent proportion affected the material melting temperature.


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