Physico-Mechanical Properties of Cellulose Acetate Butyrate/ Yellow Poplar Wood Fiber Composites as a Function of Fiber Aspect Ratio, Fiber Loading, and Fiber Acetylation

2012 ◽  
Vol 1 (2) ◽  
pp. 371-383
Author(s):  
◽  
M. E. Enyiegbulam ◽  
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
Cellulose Acetate ◽  
Wood Fiber ◽  
Fiber Composites ◽  
Poplar Wood ◽  
Yellow Poplar ◽  
Fiber Loading ◽  
Fiber Aspect Ratio ◽  
Acetate Butyrate

Modeling the Large Deformation and Microstructure Evolution of Nonwoven Polymer Fiber Networks

2018 ◽  
Vol 86 (1) ◽  
Author(s):  
Mang Zhang ◽  
Yuli Chen ◽  
Fu-pen Chiang ◽  
Pelagia Irene Gouma ◽  
Lifeng Wang
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
Mechanical Behavior ◽  
Large Deformation ◽  
Biological Tissues ◽  
High Porosity ◽  
Polymer Fiber ◽  
Fiber Networks ◽  
Fiber Aspect Ratio ◽  
Network Microstructure

The electrospinning process enables the fabrication of randomly distributed nonwoven polymer fiber networks with high surface area and high porosity, making them ideal candidates for multifunctional materials. The mechanics of nonwoven networks has been well established for elastic deformations. However, the mechanical properties of the polymer fibrous networks with large deformation are largely unexplored, while understanding their elastic and plastic mechanical properties at different fiber volume fractions, fiber aspect ratio, and constituent material properties is essential in the design of various polymer fibrous networks. In this paper, a representative volume element (RVE) based finite element model with long fibers is developed to emulate the randomly distributed nonwoven fibrous network microstructure, enabling us to systematically investigate the mechanics and large deformation behavior of random nonwoven networks. The results show that the network volume fraction, the fiber aspect ratio, and the fiber curliness have significant influences on the effective stiffness, effective yield strength, and the postyield behavior of the resulting fiber mats under both tension and shear loads. This study reveals the relation between the macroscopic mechanical behavior and the local randomly distributed network microstructure deformation mechanism of the nonwoven fiber network. The model presented here can also be applied to capture the mechanical behavior of other complex nonwoven network systems, like carbon nanotube networks, biological tissues, and artificial engineering networks.

Mechanical Properties of Electrospun Carbon Nano Fiber (ECNF)/Epoxy Nanocomposites

2007 ◽  
Author(s):  
Darunee Aussawasathien ◽  
Erol Sancaktar
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
Epoxy Resin ◽  
Carbon Nanofiber ◽  
Mechanical Analysis ◽  
Short Fiber ◽  
Neat Epoxy ◽  
Epoxy Nanocomposites ◽  
Cure Reaction ◽  
Fiber Aspect Ratio

Electrospun polyacrylonitrile (PAN) fiber precursor based Carbon Nanofiber (CNF) mats were produced and impregnated with epoxy resin. The mechanical properties of as-prepared nanofibers in the mat and short fiber filled epoxy nanocomposite forms were determined to demonstrate the effect of fiber aspect ratio and interconnecting network on those properties. Our experimental results reveal that epoxy nanocomposites containing Electrospun Carbon Nano Fibers (ECNF) with high fiber aspect ratio and high interconnecting network in the non-woven mat form yield better mechanical properties than those filled with short ECNFs. The ECNF mat in epoxy nanocomposites provides better homogeneity, more interlocking network, and easier preparation than short ECNFs. Mechanical properties of ECNF mat-epoxy nanocomposites, which we obtained using tensile and flexural tests, such as stiffness and modulus increased, while toughness and flexural strength decreased, compared to the neat epoxy resin. Dynamic Mechanical Analysis (DMA) results showed, higher modulus for ECNF mat-epoxy nanocomposites, compared to those for neat epoxy resin and short ECNF-epoxy nanocomposites. The epoxy nanocomposites had high modulus, even though the glass transition temperature, Tg values dropped at some extents of ECNF mat contents when compared with the neat epoxy resin. The cure reaction was retarded since the amount of epoxy and hardener decreased at high ECNF contents together with the hindering effect of the ECNF mat to the diffusion of epoxy resin and curing agent, leading to low crosslinking efficiency.

Cellulose acetate butyrate/poly(caprolactonetriol) blends: Miscibility, mechanical properties, and in vivo inflammatory response

2014 ◽  
Vol 29 (5) ◽  
pp. 654-661 ◽  
Author(s):  
Luiz A Kanis ◽  
Ellen L Marques ◽  
Karine M Zepon ◽  
Jefferson R Pereira ◽  
Saulo Pamato ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bonding ◽  
Inflammatory Response ◽  
Cellulose Acetate ◽  
Intramolecular Hydrogen Bonding ◽  
Cellulose Acetate Butyrate ◽  
Swelling Capacity ◽  
Intramolecular Hydrogen ◽  
Acetate Butyrate

This study reports the results of the characterization of cellulose acetate butyrate and polycaprolactone-triol blends in terms of miscibility, swelling capacity, mechanical properties, and inflammatory response in vivo. The cellulose acetate butyrate film was opaque and rigid, with glass transition ( T g) at 134℃ and melting temperature of 156℃. The cellulose acetate butyrate/polycaprolactone-triol films were transparent up to a polycaprolactone-triol content of 60%. T g of the cellulose acetate butyrate films decreased monotonically as polycaprolactone-triol was added to the blend, thus indicating miscibility. FTIR spectroscopy revealed a decrease in intramolecular hydrogen bonding in polycaprolactone-triol, whereas no hydrogen bonding was observed between cellulose acetate butyrate and –OH from polycaprolactone-triol. The increase in polycaprolactone-triol content in the blend decreased the water uptake. An increase in polycaprolactone-triol content decreased the modulus of elasticity and increased the elongation at break. A cellulose acetate butyrate/polycaprolactone-triol 70/30 blend implanted in rats showed only an acute inflammatory response 7 days after surgery. No change in inflammation mediators was observed.

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.

scholarly journals The Effects Of Mixing And Curing On Morphological And Mechanical Properties Of Epoxy-Albasia Composites

2016 ◽  
Vol 2 ◽  
pp. 55 ◽  
Author(s):  
Henny Pratiwi
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Mixing Time ◽  
Wood Fiber ◽  
Fiber Composites ◽  
Crack Deflection ◽  
Curing Temperature ◽  
Propagation Path ◽  
Time Variations ◽  
The Impact

This research is aimed to know the effect of mixing time, mixing speed and curing temperature on morphological and mechanical properties of epoxy-albasia wood fiber composites. The method used in the manufacturing process was hand lay-up method. The fibers with 30 mesh and 25% volume fraction are mixed with epoxy for the time variations of 15 and 45 minutes by speed variation of 695 rpm, 773 rpm, and 853 rpm. In order to investigate the effects of curing temperature, the same mixture was blended manually for 20 minutes and cured with the temperature variation of 40, 50, 60, 70 and 800C. Experimental results show that mixing the fiber and matrix with the speed of 695 rpm for 15 minutes increases the tensile strength but slightly declines the impact strength. This phenomenon could be possibly caused by the longer the mixing time, the higher the amount of foreign particles entered into the mixture that could affect its properties. Both the tensile and impact tests show that the temperature of 80oC is the optimum curing temperature for epoxy-albasia wood fiber composites. Crack deflection presented by Scanning Electron Microscopy (SEM) micrographs results in an increase in the crack propagation path and in the energy-dissipating events in the region immediately ahead of the crack tip.

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