Preparation and characterization of high-performance wood polymer nanocomposites using multi-walled carbon nanotubes

2016 ◽  
Vol 51 (9) ◽  
pp. 1187-1195 ◽  
Author(s):  
Alperen Kaymakci ◽  
Nadir Ayrilmis ◽  
Turker Gulec ◽  
Mursit Tufan

Effect of industrial grade multi-walled carbon nanotubes on mechanical, decay, and thermal properties of wood polymer nanocomposites was investigated. To meet this objective, pine wood flour, polypropylene with and without coupling agent (maleic anhydride grafted polypropylene), and multi-walled carbon nanotube (0, 1, 3, 5 wt%) were compounded in a twin screw co-rotating extruder. The mass ratio of the wood flour to polypropylene was 50/50 (w/w) in all compounds. Test specimens were produced using injection molding machine from the pellets. The flexural and tensile properties, biological durability, and thermal analysis (thermogravimetric analysis and differential scanning calorimetry) of the nanocomposites were investigated. The flexural and tensile properties of the wood polymer nanocomposites increased with increasing content of the industrial grade multi-walled carbon nanotubes (from 1 to 5 wt%) and maleic anhydride grafted polypropylene (3 wt%). The mass loss rates of the wood polymer nanocomposites decreased with increasing amounts of the maleic anhydride grafted polypropylene and industrial grade multi-walled carbon nanotube. The differential scanning calorimetry analysis showed that the melt crystallization enthalpies of the wood polymer nanocomposites increased with increasing amount of the industrial grade multi-walled carbon nanotubes. The increase in the Tc indicated that the industrial grade multi-walled carbon nanotubes were the efficient nucleating agent for the wood polymer nanocomposites.

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.


Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 84
Author(s):  
Yi-Ming Jen ◽  
Hao-Huai Chang ◽  
Chien-Min Lu ◽  
Shin-Yu Liang

Even though the characteristics of polymer materials are sensitive to temperature, the mechanical properties of polymer nanocomposites have rarely been studied before, especially for the fatigue behavior of hybrid polymer nanocomposites. Hence, the tensile quasi-static and fatigue tests for the epoxy nanocomposites reinforced with multi-walled carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) were performed at different temperatures in the study to investigate the temperature-dependent synergistic effect of hybrid nano-fillers on the studied properties. The temperature and the filler ratio were the main variables considered in the experimental program. A synergistic index was employed to quantify and evaluate the synergistic effect of hybrid fillers on the studied properties. Experimental results show that both the monotonic and fatigue strength decrease with increasing temperature significantly. The nanocomposites with a MWCNT (multi-walled CNT): GNP ratio of 9:1 display higher monotonic modulus/strength and fatigue strength than those with other filler ratios. The tensile strengths of the nanocomposite specimens with a MWCNT:GNP ratio of 9:1 are 10.0, 5.5, 12.9, 23.4, and 58.9% higher than those of neat epoxy at −28, 2, 22, 52, and 82 °C, respectively. The endurance limits of the nanocomposites with this specific filler ratio are increased by 7.7, 26.7, 5.6, 30.6, and 42.4% from those of pristine epoxy under the identical temperature conditions, respectively. Furthermore, the synergistic effect for this optimal nanocomposite increases with temperature. The CNTs bridge the adjacent GNPs to constitute the 3-D network of nano-filler and prevent the agglomeration of GNPs, further improve the studied strength. Observing the fracture surfaces reveals that crack deflect effect and the bridging effect of nano-fillers are the main reinforcement mechanisms to improve the studied properties. The pullout of nano-fillers from polymer matrix at high temperatures reduces the monotonic and fatigue strengths. However, high temperature is beneficial to the synergistic effect of hybrid fillers because the nano-fillers dispersed in the softened matrix are easy to align toward the directions favorable to load transfer.


2019 ◽  
Vol 30 (8) ◽  
pp. 1216-1224 ◽  
Author(s):  
Mohammad Charara ◽  
Mohammad Abshirini ◽  
Mrinal C Saha ◽  
M Cengiz Altan ◽  
Yingtao Liu

This article presents three-dimensional printed and highly sensitive polydimethylsiloxane/multi-walled carbon nanotube sensors for compressive strain and pressure measurements. An electrically conductive polydimethylsiloxane/multi-walled carbon nanotube nanocomposite is developed to three-dimensional print compression sensors in a freestanding and layer-by-layer manner. The dispersion of multi-walled carbon nanotubes in polydimethylsiloxane allows the uncured nanocomposite to stand freely without any support throughout the printing process. The cross section of the compression sensors is examined under scanning electron microscope to identify the microstructure of nanocomposites, revealing good dispersion of multi-walled carbon nanotubes within the polydimethylsiloxane matrix. The sensor’s sensitivity was characterized under cyclic compression loading at various max strains, showing an especially high sensitivity at lower strains. The sensing capability of the three-dimensional printed nanocomposites shows minimum variation at various applied strain rates, indicating its versatile potential in a wide range of applications. Cyclic tests under compressive loading for over 8 h demonstrate that the long-term sensing performance is consistent. Finally, in situ micromechanical compressive tests under scanning electron microscope validated the sensor’s piezoresistive mechanism, showing the rearrangement, reorientation, and bending of the multi-walled carbon nanotubes under compressive loads, were the main reasons that lead to the piezoresistive sensing capabilities in the three-dimensional printed nanocomposites.


RSC Advances ◽  
2015 ◽  
Vol 5 (125) ◽  
pp. 103365-103372 ◽  
Author(s):  
Lei Liu ◽  
Dong Wang ◽  
Yuan Hu

Negative graphene oxide was combined with positive chitosan-modified multi-walled carbon nanotubes in aqueous solution and then thermally reduced to fabricate a multi-walled carbon nanotube/graphene (MWCNT/G) hybrid material.


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.


2016 ◽  
Vol 4 (21) ◽  
pp. 3823-3831 ◽  
Author(s):  
Stefano Fedeli ◽  
Alberto Brandi ◽  
Lorenzo Venturini ◽  
Paola Chiarugi ◽  
Elisa Giannoni ◽  
...  

An efficient drug delivery system through a straightforward approach to multi-walled carbon nanotube decoration.


RSC Advances ◽  
2017 ◽  
Vol 7 (45) ◽  
pp. 28556-28563 ◽  
Author(s):  
Jianzhi Huang ◽  
Silan Bai ◽  
Guoqing Yue ◽  
Wenxue Cheng ◽  
Lishi Wang

Coordination matrix/signal amplifier strategy for simultaneous electrochemical determination of cadmium(ii), lead(ii), copper(ii) and mercury(ii) ions based on polyfurfural film/multi-walled carbon nanotubes modified electrode.


RSC Advances ◽  
2015 ◽  
Vol 5 (10) ◽  
pp. 7237-7244 ◽  
Author(s):  
Xiaoyu Li ◽  
Hongbo Gu ◽  
Jiurong Liu ◽  
Huige Wei ◽  
Song Qiu ◽  
...  

The multi-walled carbon nanotube (MWNT) nanocomposites with homogenously anchored nanomagnetite of 10–20 nm prepared by a hydrothermal-annealing method exhibit excellent performances as anode materials for lithium ion batteries.


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