scholarly journals Preparation of Transparent and Thick CNF/Epoxy Composites by Controlling the Properties of Cellulose Nanofibrils

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 625 ◽  
Author(s):  
Shin Young Park ◽  
Simyub Yook ◽  
Sooim Goo ◽  
Wanhee Im ◽  
Hye Jung Youn
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Cellulose Nanofibrils ◽  
High Light ◽  
Epoxy Composites ◽  
Light Transmittance ◽  
High Transparency ◽  
Preparation Conditions ◽  
Optically Transparent ◽  
Optical And Mechanical Properties

Cellulose nanofibrils (CNFs) have been used as reinforcing elements in optically transparent composites by combination with polymer matrices. In this study, strong, optically transparent, and thick CNF/epoxy composites were prepared by immersing two or four layers of CNF sheets in epoxy resin. The morphology of the CNF, the preparation conditions of the CNF sheet, and the grammage and layer numbers of the CNF sheets were controlled. The solvent-exchanged CNF sheets resulted in the production of a composite with high transparency and low haze. The CNF with smaller width and less aggregated fibrils, which are achieved by carboxymethylation, and a high number of grinding passes are beneficial in the production of optically transparent CNF/epoxy composites. Both the grammage and number of stacked layers of sheets in a composite affected the optical and mechanical properties of the composite. A composite with a thickness of 450–800 μm was prepared by stacking two or four layers of CNF sheets in epoxy resin. As the number of stacked sheets increased, light transmittance was reduced and the haze increased. The CNF/epoxy composites with two layers of low grammage (20 g/m2) sheets exhibited high light transmittance (>90%) and low haze (<5%). In addition, the composites with the low grammage sheet had higher tensile strength and elastic modulus compared with neat epoxy and those with high grammage sheets.

Study on Electron Beam Curing of APTES Functionalized MWNTs/ Epoxy Composites

2011 ◽  
Vol 194-196 ◽  
pp. 1607-1610
Author(s):  
Yan Yan Lu ◽  
Hua Li ◽  
He Zhou Liu
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Epoxy Resin ◽  
Conversion Rate ◽  
Epoxy Composites ◽  
Pure Epoxy ◽  
Gel Content ◽  
Electron Beam Curing ◽  
Irradiation Process

In this study, we prepared the 3-aminopropyltriethoxysilane (APTES) functionalized MWNTs/epoxy composites by electron beam (EB) irradiation process. The modified MWNTs were characterized with SEM-EDS and FTIR. The gel content and conversion rate of epoxide groups of the EB cured pure epoxy resin and the APTES functionalized MWNTs/epoxy composites were measured and discussed. And the mechanical properties of the EB cured composites were also characterized. With addition of 0.25wt% APTES functionalized MWNTs, the Vicker’s hardness of the EB cured composite increased 100.02% compared with pure epoxy.

scholarly journals Recent Advances on Renewable and Biodegradable Cellulose Nanopaper Substrates for Transparent Light-Harvesting Devices: Interaction with Humid Environment

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Alessandra Operamolla
Keyword(s):  
Mechanical Properties ◽  
Printed Electronics ◽  
Photovoltaic Devices ◽  
High Transparency ◽  
Humid Environment ◽  
Absorption Of Light ◽  
Cellulose Nanopaper ◽  
Optical And Mechanical Properties ◽  
State Of Art ◽  
The Ideal

Cellulose nanopaper (CNP) has attracted much interest during the last decade as a new fascinating renewable and biodegradable substrate for printed electronics and solar cells. Its outstanding optical and mechanical properties make CNP the ideal substrate for the preparation of photovoltaic devices, since its high transparency and haze favour the absorption of light from the active layer of the solar cell. However, some advances need to be done in the direction of increasing CNP stability in humid environment without compromising its remarkable advantages. This review critically points at these aspects, presenting an overview of state-of-art solutions to enhance nanopaper stability in a humid environment.

scholarly journals Study the effect of fiber loading and alkali treatment on the mechanical and water absorption properties of wheat straw fiber-reinforced epoxy composites

2017 ◽  
Vol 24 (5) ◽  
pp. 731-738 ◽  
Author(s):  
Varun Mittal ◽  
Shishir Sinha
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Epoxy Resin ◽  
Wheat Straw ◽  
Alkali Treatment ◽  
Fiber Composites ◽  
Epoxy Composites ◽  
Absorption Properties ◽  
Fiber Loading ◽  
Treated Fiber

AbstractThe aim of this research was to study the feasibility of using wheat straw fiber with epoxy resin for developing natural fiber-polymer composites. For this purpose, the epoxy resin was reinforced with 5, 10, 15, 20, and 25 wt.% of the wheat straw fiber with the help of the hand lay-up technique. Further, in order to improve the composite characteristic, wheat straw fibers were treated with three different concentrations of alkali (1%, 3%, and 5%). The mechanical and water absorption properties of the treated fiber composites were characterized and compared with those of untreated fiber-filled epoxy composites. It was observed that the mechanical properties and water resistance were reduced with the increase in wheat straw fiber loading from 5 to 25 wt.%. Among the three levels of alkali treatment, the composite made with 3% alkali-treated fiber exhibited superior mechanical properties than the other untreated and treated fiber composites, which pointed to an efficient fiber-matrix adhesion. The scanning electron microscope was used to observe the surface features of the wheat straw fiber.

Carbon Fiber Powder Reinforced Epoxy Composites used for Rapid Tooling

2011 ◽  
Vol 287-290 ◽  
pp. 197-200
Author(s):  
Hai Qing Hu ◽  
Li Zhao ◽  
Jia Qiang Liu ◽  
Shi Bao Wen ◽  
Yong Jiang Gu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Glass Fiber ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Rapid Tooling ◽  
Epoxy Composites ◽  
Waste Materials ◽  
Ultrasonic Time ◽  
Good For

Carbon fiber powder (CFP) instead of the traditional glass fiber (cloth) was used to reinforce epoxy resin for rapid tooling. There are two obvious advantages: one is to utilize the waste materials, which is good for the protection of the environment; another is to simplify the producing process by cast molding. The filling amount and dispersing process of CFP was studied in this paper. The results show that when the amount of CFP was 10 wt%, and the ultrasonic time is more than 15 min, the CFP can be dispersed in the epoxy matrix uniformly, and the mechanical properties can meet the requirement of epoxy molding.

scholarly journals Hybrid films of cellulose nanofibrils, chitosan and nanosilica—Structural, thermal, optical, and mechanical properties

2019 ◽  
Vol 218 ◽  
pp. 87-94 ◽  
Author(s):  
Mostafa Y. Ismail ◽  
Minna Patanen ◽  
Juho Antti Sirviö ◽  
Miikka Visanko ◽  
Takuji Ohigashi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cellulose Nanofibrils ◽  
Hybrid Films ◽  
Optical And Mechanical Properties

Thermal and Mechanical Properties of Epoxy Resin Functionalized Copper and Graphene Hybrids using In-situ Polymerization Method

2020 ◽  
Vol 16 ◽  
Author(s):  
Nadia A. Ali ◽  
Alaa M. Abd-Elnaiem ◽  
Seenaa I. Hussein ◽  
Asmaa Sh. Khalil ◽  
Hatem R. Alamri ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Wear Resistance ◽  
Epoxy Resin ◽  
Hybrid Composite ◽  
Hybrid Composites ◽  
Weight Ratio ◽  
Epoxy Composites ◽  
Thermal And Mechanical Properties ◽  
Maximum Hardness

Objective: In this work, graphene (Gr) or/and Cu particles are used to improve the thermal and mechanical properties of epoxy resin. Methods: Various contents of Gr powder (0.1, 0.3, and 0.5 wt%), Cu powder (10, 30, and 50 wt%) were loaded to epoxy to form Gr/epoxy and Cu/epoxy composites, respectively. In addition, hybrids epoxy/Cu/Gr samples were prepared with a selection of lowest (0.1 and 10) and highest (0.5 and 50) ratios of Gr, and Cu, respectively. Results: The thermal conductivity increases with the increasing weight ratio of Gr and Cu as compared to the pure epoxy. The Thermogravimetric analysis (TGA) of epoxy composites and hybrid composites reveals an improvement in the thermal stability. In addition, the mechanical properties such as hardness shore D and the wear resistance are enhanced for both the epoxy composites and hybrids composites. However, the Ep+0.5wt%Gr+50wt%Cu hybrid composite has the maximum hardness 84, thermal conductivity of 3.84 W/m.K, it shows the lowest wear resistance 2.7×10-6 mm3/Nm at loading 10 N. Conclusion: The hybrid composite containing 0.5wt%Gr and 50wt%Cu shows the maximum hardness and thermal conductivity, as well as the lowest wear resistance when compared to other composites. The physical properties of the hybrid composite can be controlled by the host blend, and hence the morphology, and interfacial characteristics.

scholarly journals Preparation and Properties Study of PVA/Bamboo Cellulose Composite Membrane

2022 ◽  
Vol 58 (4) ◽  
pp. 19-27
Author(s):  
Peng Jian Xiang ◽  
Zhu Xiao Rao ◽  
Sun Shi Dong ◽  
Zhu He Ping
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Film ◽  
Composite Membrane ◽  
High Light ◽  
Bamboo Fiber ◽  
Light Transmittance ◽  
Transparent Material ◽  
Reinforcing Material ◽  
Cellulose Composite

The effect of bamboo fiber content on mechanical properties, moisture permeability and light transmittance of composite membrane was studied. The results show that the tensile strength of the composite film is increased by 30%, and the mechanical properties of PVA film are improved obviously with the addition of bamboo cellulose, which can be used as a good reinforcing material of PVA matrix. Bamboo cellulose composite film is a kind of transparent material because of its high light transmittance.

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