High performance polyurethane/functionalized graphene nanocomposites with improved mechanical and thermal properties

2012 ◽  
Vol 72 (6) ◽  
pp. 702-707 ◽  
Author(s):  
Dongyu Cai ◽  
Jie Jin ◽  
Kamal Yusoh ◽  
Rehman Rafiq ◽  
Mo Song
2016 ◽  
Vol 56 (11) ◽  
pp. 1221-1228 ◽  
Author(s):  
Suman Chhetri ◽  
Pranab Samanta ◽  
Naresh Chandra Murmu ◽  
Suneel Kumar Srivastava ◽  
Tapas Kuila

2018 ◽  
Vol 31 (6) ◽  
pp. 719-732 ◽  
Author(s):  
Abdeldjalil Zegaoui ◽  
Mehdi Derradji ◽  
Abdul Qadeer Dayo ◽  
Aboubakr Medjahed ◽  
Hui-yan Zhang ◽  
...  

The investigation and design of new polymeric materials with an astonishing combination of properties are nowadays of great importance to facilitate the manufacturing process of high-quality products intended to be utilized in different applications and technical fields. For this intent, novel high-performance blend composites composed of the cyanate ester/benzoxazine resin blend reinforced by different proportions of silane-surface modified Kevlar and glass fibers were successfully fabricated by a compression molding technique and characterized by different experimental tests. The mechanical test results revealed that the bending and impact strength properties were considerably improved when increasing the amount of the hybrid fibers. The studied materials also presented excellent thermal stabilities as compared to the unfilled blend’s properties. With respect to the properties of the reinforcing systems, these improvements seen in either the mechanical or thermal properties could be due to the good dispersion as well as excellent adhesion of the reinforcing fibers inside the resin matrix, which were further evidenced by the Fourier transform infrared spectroscopy and scanning electron microscopy results. Consequently, the improved mechanical and thermal properties promote the use of the fabricated hybrid composites in domestic and industrial applications requiring functional materials with advanced properties for aerospace and military applications.


2019 ◽  
Vol 54 (15) ◽  
pp. 1961-1976
Author(s):  
Xu Xiangmin ◽  
Hongxiang Zhang ◽  
Tong Beibei ◽  
Li Binjie ◽  
Yudong Zhang

The advanced multifunctional filler has become one of the main challenges in developing high-performance polymer composites. In this study, the acid-treated multiwall carbon nanotubes (MWCNTs) were adhered to the surface of milled glass fiber under the combined effect of 3-aminopropyltriethyloxy silane and tetraethyl orthosilicate to fabricate a hierarchical fiber (MWCNTs-MGF). The morphologies of the hierarchical fibers were characterized using field-emission scanning electron microscope and transmission electron microscope, which showed evidence of a coating layer of MWCNTs on each fiber surface. The MWCNTs-MGF was employed as a multifunctional filler to prepare polyoxymethylene-based composites using a twin-screw extruder by melt blending. The obtained composites exhibited improved mechanical and thermal properties. The composite tensile strength and notched impact strength and Young's modulus increased by 10%, 32%, and 32%, respectively, as the MWCNTs-MGF content varies from 0 to 10 wt.%. Meanwhile, the reinforcing and toughing mechanisms of MWCNTs-MGF were also elaborated by analyzing the interfacial adhesion and fracture morphologies of the composites. Moreover, the study on thermal stability and crystallization behavior indicated that the polyoxymethylene/MWCNTs-MGF composites had higher thermal stability, crystallization temperature, and crystallinity as compared to the polymer matrix. The improvement of thermal stability originates from the unique surface structure of MWCNTs-MGF, while the increase in crystallization temperature and crystallinity is due to the strong heterogeneous nucleation ability of the hierarchical fibers.


2018 ◽  
Vol 22 ◽  
pp. 23-33 ◽  
Author(s):  
Seenaa I. Hussein

In this research, we have prepared epoxy/graphene nanocomposites (graphene content: 1, 3, 5, 7, and 9 wt%) to investigate some mechanical (impact strength, hardness, and Brazilian tests) and thermal properties (thermal conductivity and thermogravimetric analysis). Our results show that the impact strength, hardness, and compression strength values increased to 5.04 kJ/m2, 79.8, and 27.85 MPa, respectively, as increasing graphene content up to 5 wt% and then decreased for further increasing of the graphene content. The observed reduction in the hardness could be attributed to the samples brittleness. On the other hand, the thermal conductivity increased with increasing the graphene content because of the high thermal conductivity of graphene and thus the efficiency increase with increasing of graphene content. In addition, the thermal stability of epoxy/graphene composite increase compared with pure epoxy resin, while the activation energy for samples consists of 9 wt% graphene greater than those containing 1 wt% graphene.


2020 ◽  
pp. 002199832095318
Author(s):  
RMR Shagor ◽  
F Abedin ◽  
R Asmatulu

The use of nanofillers to enhance the properties of fiber reinforced composites is limited due to the adverse effect on mechanical properties caused by agglomeration of these nanofillers in the matrix materials. In this study, graphene nanoflakes were functionalized with silane moiety to improve its dispersion, stability and bond strengths in the polymer matrices of the carbon fiber reinforced composites. Wet layup process was applied to incorporate graphene nanocomposites into the dry carbon fibers to make composite panels following the curing cycle of the epoxy and hardener. The impacts of the functionalized graphene on the mechanical and thermal properties of carbon reinforced composite were investigated in detail by tensile test, differential scanning calorimetry, dynamic mechanical analysis and scanning electron microscopy (SEM) analysis. It was observed that nanocomposites with 0.5 wt% silanized graphene exhibited maximum tensile strength and modulus of elasticity, indicating that 0.50 wt% silane functionalized graphene was the optimum nanofiller composition amongst the three different compositions investigated. The nanocomposites with 0.25 wt% and 0.50 wt% nanofillers showed improved ductility compared to the control sample. Based on the SEM studies on the crack zones, major morphological changes were observed after the salinization process. The interfacial interaction between epoxy and silane moiety of the graphene and reduction in the tendency to agglomerate could account for the improved properties of the nanocomposite observed here. Nanocomposites with silanized graphene showed overall higher glass transition temperature (Tg) and tensile strength than those with pristine graphene and control samples.


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