scholarly journals Mechanical and Functional Properties of Novel Biobased Poly(decylene-2,5-furanoate)/Carbon Nanotubes Nanocomposite Films

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2459
Author(s):  
Giulia Fredi ◽  
Andrea Dorigato ◽  
Mauro Bortolotti ◽  
Alessandro Pegoretti ◽  
Dimitrios N. Bikiaris

The present work investigates the microstructural, thermo-mechanical, and electrical properties of a promising, but still not thoroughly studied, biobased polymer, i.e., poly(decylene furanoate) (PDeF), and its performance when multi-walled carbon nanotubes (CNTs) are added. After sample preparation by solution mixing and film casting, the microstructural investigation evidences that the fracture surface becomes smoother and more homogeneous with a small fraction of CNTs, and that the production process is suitable to achieve good disentanglement and dispersion of CNTs within the matrix, although some aggregates are still observable. CNTs act as nucleating agents for PDeF crystals, as evidenced by differential scanning calorimetry, as the crystallinity degree increases from 43.2% of neat PDeF to 55.0% with a CNT content of 2 phr, while the crystallization temperature increases from 68.4 °C of PDeF to 91.7 °C of PDeF-CNT-2. A similar trend in crystallinity is confirmed by X-ray diffraction, after detailed Rietveld analysis with a three-phase model. CNTs also remarkably improve the mechanical performance of the bioderived polymer, as the elastic modulus increases up to 123% and the stress at break up to 131%. The strain at break also increases by +71% when a small amount of 0.25 phr of CNTs are added, which is probably the consequence of a more homogeneous microstructure. The long-term mechanical performance is also improved upon CNT addition, as the creep compliance decreases considerably, which was observed for both the elastic and the viscoelastic component. Finally, the films become electrically dissipative for a CNT content of 1 phr and conductive for a CNT amount of 2 phr. This study contributes to highlight the properties of bioderived furan-based polymer PDeF and evidences the potential of CNTs as a promising nanofiller for this matrix.

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2138 ◽  
Author(s):  
José Carlos Alcántara ◽  
Israel González ◽  
M. Mercè Pareta ◽  
Fabiola Vilaseca

Agricultural residues are major potential resources for biomass and for material production. In this work, rice straw residues were used to isolate cellulose nanofibers of different degree of oxidation. Firstly, bleached rice fibers were produced from the rice straw residues following chemical extraction and bleaching processes. Oxidation of rice fibers mediated by radical 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) at pH 10 was then applied to extract rice cellulose nanofibers, with diameters of 3–11 nm from morphological analysis. The strengthening capacity of rice nanofibers was tested by casting nanocomposite films with poly(vinyl alcohol) polymer. The same formulations with eucalyptus nanofibers were produced as comparison. Their thermal and mechanical performance was evaluated using thermogravimetry, differential scanning calorimetry, dynamic mechanical analysis and tensile testing. The glass transition of nanocomposites was shifted to higher temperatures with respect to the pure polymer by the addition of rice cellulose nanofibers. Rice nanofibers also acted as a nucleating agent for the polymer matrix. More flexible eucalyptus nanofibers did not show these two phenomena on the matrix. Instead, both types of nanofibers gave similar stiffening (as Young’s modulus) to the matrix reinforced up to 5 wt.%. The ultimate tensile strength of nanocomposite films revealed significant enhancing capacity for rice nanofibers, although this effect was somehow higher for eucalyptus nanofibers.


2021 ◽  
Author(s):  
A. Abdeldaym ◽  
M. A. Elhady

Abstract Reinforcement of the flexible shielding properties of natural rubber (NRL) was achieved through various content Multi-walled carbon nanotubes (MWCNTs) prepared from a simple solution using mixing method. Thereafter, a host of evaluative tests, using different techniques were carried to check the structural, morphological, mechanical and electrical conformity of the MWCNTs in the natural rubber matrix. More notably, the results from the x-ray diffraction (XRD), Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) revealed that the nanocomposites have been successfully prepared, making them fitting to impact significant improvement on the mechanical strength of the matrix. The evaluation of the formation of MWCNT networks in the matrix, which gives insight into the nanocomposites' electrical conductivity, also showed agreeable results as the linear attenuation coefficients (l) and half-value thickness (HVT) for NRL/MWCNTs nanocomposite films were investigated . Thus, from the foregoing series of results, it can be concluded that nanocomposite films offer promising radiation-shielding properties.


2016 ◽  
Vol 51 (6) ◽  
pp. 745-758 ◽  
Author(s):  
Masoumeh Nazem Salimi ◽  
Mehdi Torabi Merajin ◽  
Mohammad Kazem Besharati Givi

Hybrid composites are being used in a wide variety of applications especially in the aircraft industry. Therefore, it would be of great use to develop a hybrid composite with a high mechanical performance. With this premise, this studyaimed to imbed secondary nanoscale reinforcement into the matrix of glass/carbon/epoxy composite where amino multi-walled carbon nanotubes and hybridization of amino multi-walled carbon nanotube and Nanoclay (Cloisite 30B) were utilized. The tensile, flexural and impact properties of hybrid composites were evaluated and a comparative study between hybrid composite reinforced with amino-MWCNTs and simultaneous amino-MWCNTs and Nanoclay was conducted. The fractured surfaces of tensile testing and bending testing specimens were characterized with a high precise field emission scanning electron microscopy. The results of the tensile test revealed that incorporation of amino-MWCNTs reduced the ultimate strength of hybrid composite, while the elastic modulus of composite with combination of amino-MWCNTs and Nanoclay increased. It was demonstrated that incorporation of nanotubes and simultaneous presence of both amino MWCNTs and Nanoclay could enhance exclusively the flexural strength of conventional hybrid composite by up to 10.5% and 22% respectively. Also, simultaneous presence of nano-fillers resulted in 12.2% enhancement of impact strength of hybrid composite where amino-MWCNTs exclusively increased it by up to 49.9%. Morphological characterization of composites indicated to strengthen interfacial interaction of fabrics to epoxy when matrix reinforced with nano-fillers, especially in combination of both nanotubes and nanoclays.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1383
Author(s):  
Jerzy Korol ◽  
Aleksander Hejna ◽  
Klaudiusz Wypiór ◽  
Krzysztof Mijalski ◽  
Ewelina Chmielnicka

The recycling of plastics is currently one of the most significant industrial challenges. Due to the enormous amounts of plastic wastes generated by various industry branches, it is essential to look for potential methods for their utilization. In the presented work, we investigated the recycling potential of wastes originated from the agricultural films recycling line. Their structure and properties were analyzed, and they were modified with 2.5 wt % of commercially available compatibilizers. The mechanical and thermal performance of modified wastes were evaluated by tensile tests, thermogravimetric analysis, and differential scanning calorimetry. It was found that incorporation of such a small amount of modifiers may overcome the drawbacks caused by the presence of impurities. The incorporation of maleic anhydride-grafted compounds enhanced the tensile strength of wastes by 13–25%. The use of more ductile compatibilizers—ethylene-vinyl acetate and paraffin increased the elongation at break by 55–64%. The presence of compatibilizers also reduced the stiffness of materials resulting from the presence of solid particles. It was particularly emphasized for styrene-ethylene-butadiene-styrene and ethylene-vinyl acetate copolymers, which caused up to a 20% drop of Young’s modulus. Such effects may facilitate the further applications of analyzed wastes, e.g., in polymer film production. Thermal performance was only slightly affected by compatibilization. It caused a slight reduction in polyethylene melting temperatures (up to 2.8 °C) and crystallinity degree (up to 16%). For more contaminated materials, the addition of compatibilizers caused a minor reduction in the decomposition onset (up to 6 °C). At the same time, for the waste after three washing cycles, thermal stability was improved. Moreover, depending on the desired properties and application, materials do not have to go through the whole recycling line, simplifying the process, reducing energy and water consumption. The presented results indicate that it is possible to efficiently use the materials, which do not have to undergo the whole recycling process. Despite the presence of impurities, they could be applied in the manufacturing of products which do not require exceptional mechanical performance.


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.


2012 ◽  
Vol 79 ◽  
pp. 41-46 ◽  
Author(s):  
Fabia Galantini ◽  
Sabrina Bianchi ◽  
Valter Castelvetro ◽  
Irene Anguillesi ◽  
Giuseppe Gallone

Among the broad class of electro-active polymers, dielectric elastomer actuators represent a rapidly growing technology for electromechanical transduction. In order to further develop this applied science, the high driving voltages currently needed must be reduced. For this purpose, one of the most promising and adopted approach is to increase the dielectric constant while maintaining both low dielectric losses and high mechanical compliance. In this work, a dielectric elastomer was prepared by dispersing functionalised carbon nanotubes into a polyurethane matrix and the effects of filler dispersion into the matrix were studied in terms of dielectric, mechanical and electro-mechanical performance. An interesting increment of the dielectric constant was observed throughout the collected spectrum while the loss factor remained almost unchanged with respect to the simple matrix, indicating that conductive percolation paths did not arise in such a system. Consequences of the chemical functionalisation of carbon nanotubes with respect to the use of unmodified filler were also studied and discussed along with rising benefits and drawbacks for the whole composite material.


2018 ◽  
Vol 33 (5) ◽  
pp. 543-557 ◽  
Author(s):  
Jianfei Cao ◽  
Yue Lu ◽  
Hechun Chen ◽  
Lifang Zhang ◽  
Chengdong Xiong

Poly(etheretherketone) exhibits good biocompatibility, excellent mechanical properties, and bone-like stiffness. However, the natural bio-inertness of pure poly(etheretherketone) hinders its applications in biomedical field, especially when direct bone-implant osteo-integration is desired. For developing an alternative biomaterial for load-bearing orthopedic application, combination of bioactive fillers with poly(etheretherketone) matrix is a feasible approach. In this study, a bioactive multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite was prepared through a compounding and injection-molding process for the first time. Bioactive calcium polyphosphate was added to polymer matrix to enhance the bioactivity of the composite, and incorporation of multi-walled carbon nanotubes to composite was aimed to improve both the mechanical property and biocompatibility. Furthermore, the microstructures, surface hydrophilicity, and mechanical property of multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite, as well as the cellular responses of MC3T3-E1 osteoblast cells to this material were investigated. The mechanical testing revealed that mechanical performance of the resulting ternary composite was significantly enhanced by adding the multi-walled carbon nanotubes and the mechanical values obtained were close to or higher than those of human cortical bone. More importantly, cell culture tests showed that initial cell adhesion, cell viability, and osteogenic differentiation of MC3T3-E1 cells were significantly promoted on the multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite. Accordingly, the multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite may be used as a promising bone repair material in dental and orthopedic applications.


2019 ◽  
Vol 28 (8) ◽  
pp. 1248-1260 ◽  
Author(s):  
Xiangrong Chen ◽  
Rui Li ◽  
LZ Sun

A dynamic magneto-viscoelastic interface model is proposed to study the effective magneto-mechanical responses of magnetorheological nanocomposites filled with carbon nanotubes. It is incorporated with the fundamental micromechanics principles, microstructural magnetic and mechanical coupling, and computational homogenization procedures. The field-dependent effective dynamic stiffness and damping of randomly dispersed, chain-structured nanocomposites are investigated with the consideration of imperfect interfacial conditions among nanofillers, micro-particles and the matrix. Comparisons are performed between the model prediction and experimental data for a specific type of Fe particle-reinforced elastomer nanocomposites filled with multi-walled carbon nanotubes to demonstrate the capability of the proposed model framework.


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