Characterization and Utilization of Coconut Fibers of the Caribbean

2014 ◽  
Vol 1611 ◽  
pp. 95-104 ◽  
Author(s):  
Nadira Mathura ◽  
Duncan Cree ◽  
Ryan P. Mulligan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Micrographs ◽  
Saline Water ◽  
Gauge Length ◽  
Scanning Electron Micrographs ◽  
Coir Fiber ◽  
Coir Fibers ◽  
The Caribbean ◽  
Scanning Electron

ABSTRACTIn many tropical countries coconut (coir) fiber production is a major source of income for rural communities. The Caribbean has an abundance of coconuts but research into utilizing its by-products is limited. Environmentally friendly coir fibers are natural polymers generally discarded as waste material in this region. Research has shown that coir fiber from other parts of the world has successfully been recycled. This paper therefore investigates the mechanical properties of Caribbean coir fiber for potential applications in civil engineering.Approximately four hundred fibers were randomly taken from a coir fiber stack and subjected to retting in both distilled and saline water media. The mechanical properties of both the retted and unretted coir fibers were evaluated at weekly increments for a period of 3 months. Tensile strength test, x-ray diffraction analysis and scanning electron micrographs were used to assess trends and relationships between fiber gauge lengths, diameter, tensile strength and Young’s modulus. Diameters ranged between 0.11 mm-0.46 mm, while fiber samples were no longer than 250 mm in length. The tensile strength and strain at break decreased as the gauge length increased for both unretted and retted fibers. The opposite occurred for the relationship between the gauge length and Young’s modulus. Additionally, the tensile strength and modulus decreased as the fiber diameter increased. Neither distilled nor saline water improved the coir fiber’s crystalline index. Scanning electron micrographs qualitatively assessed fiber surfaces and captured necking and microfibril degradation at the fractured ends.The analysis revealed that the tensile strength, modulus, strain at break and crystallinity properties of the Caribbean coir fibers were comparable to commercially available coir fiber which are currently being used in many building applications.

PREPARATION OF CHAIN EXTENDED POLYURETHANE AND ITS COMPOSITES BASED ON CASTOR OIL AND COIR FIBER

2015 ◽  
Vol 1 (01) ◽  
pp. 67-70
Author(s):  
A. Malar Retna
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Castor Oil ◽  
High Performance ◽  
Chain Extender ◽  
Coir Fiber ◽  
Percentage Elongation ◽  
Polyurethane Composites ◽  
Performance Character ◽  
Scanning Electron

The chain extended polyurethane was synthesized by reacting castor oil based polyol with 4,4’-methylenebis(cyclohexyl) isocyanate and chain extender such as malonic acid. The composites have been fabricated by incorporating the coir fiber into the neat polyurethane. The polyurethane and its composites were characterized with respect to their mechanical properties such as hardness, tensile strength, percentage elongation and Young’s modulus. The morphology of neat polyurethane and its composites with coir fiber was studied using scanning electron microscope (SEM). These studies revealed the high performance character of the polyurethane composites with respect to the corresponding neat polyurethane.

AA-MMA Prepolymer Grafted LLDPE as Compatibilizer for Starch-PE Blends

2011 ◽  
Vol 374-377 ◽  
pp. 170-173
Author(s):  
Li Min Tai
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Graft Copolymerization ◽  
Reactive Extrusion ◽  
Scanning Electron Micrographs ◽  
Screw Extruder ◽  
Single Screw ◽  
Single Screw Extruder ◽  
Compatibilization Effect ◽  
Scanning Electron

Through the graft copolymerization of LLDPE and the AA-MMA prepolymer by reactive extrusion on the single-screw extruder, the LLPE-g-AA-MMA was prepared and used as compatibilizer for starch/PE blends, and then the compatibilization effect was investigated. The results exhibited that the addition of this compatibilizer substantially improved the mechanical properties, especially the tensile strength. Scanning electron micrographs of the blend specimens also supported the above observations.

scholarly journals Coir Fiber Reinforced Polypropylene Composites: Eco-friendly Byproducts

2017 ◽  
Vol 10 (1) ◽  
pp. 61-64
Author(s):  
SMG Moktadir ◽  
MU Talukder ◽  
AKO Huq ◽  
MA Gafur ◽  
AMS Chowdhury
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Saline Water ◽  
Coir Fiber ◽  
Percentage Elongation ◽  
Polypropylene Composites ◽  
Rebound Hardness ◽  
Pp Composites ◽  
Fiber Addition

Coir fiber (CF) reinforced polypropylene (PP) composites were fabricated using an extruder machine. The fiber contents were varied 5 to 20% and physico-mechanical properties as well as bio-degradability were also tested. Ultimate tensile strength and flexural strength decreases with the increases of percentages of fiber addition. Lowest percentage elongation is observed at 20% CF+PP composite which are rigid in nature. Leeb rebound hardness also decreases with the increase of percentage of raw fiber addition. The bio-degradation of different percentage of CF and PP composites in soil and saline water increased with increase of coir fiber content. Thus, it showed that higher percentage of coir fiber was produced more biodegradable and eco-friendly byproducts. However, higher percentages of coir fiber decrease the mechanical properties. A moderate percentage of coir fiber i.e. 15% CF +PP showed the good mechanical properties as well as considerable amount of bio-degradability in soil and saline water.J. Environ. Sci. & Natural Resources, 10(1): 61-64 2017

New evidence for a pressure-induced phase transformation during the indentation of silicon

1991 ◽  
Vol 6 (6) ◽  
pp. 1129-1130 ◽  
Author(s):  
G.M. Pharr ◽  
W.C. Oliver ◽  
D.S. Harding
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Thin Layer ◽  
Electron Micrographs ◽  
Metallic State ◽  
Scanning Electron Micrographs ◽  
New Evidence ◽  
Scanning Electron

Scanning electron micrographs of indents in (111) silicon reveal that a thin layer of material immediately adjacent to the indenter is plastically extruded. The fact that the material can be deformed in this way indicates that it has metallic-like mechanical properties. This is presented as new evidence that a pressure-induced phase transformation to the metallic state occurs during the indentation of silicon.

scholarly journals Coir Fibers Treated with Henna as a Potential Reinforcing Filler in the Synthesis of Polyurethane Composites

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1128
Author(s):  
Sylwia Członka ◽  
Anna Strąkowska ◽  
Agnė Kairytė
Keyword(s):  
Mechanical Properties ◽  
High Energy ◽  
Dynamic Mechanical Properties ◽  
Milling Process ◽  
Coir Fiber ◽  
Lawsonia Inermis ◽  
Coir Fibers ◽  
Mechanical Performances ◽  
The Impact ◽  
Reinforcing Filler

In this study, coir fibers were successfully modified with henna (derived from the Lawsonia inermis plant) using a high-energy ball-milling process. In the next step, such developed filler was used as a reinforcing filler in the production of rigid polyurethane (PUR) foams. The impact of 1, 2, and 5 wt % of coir-fiber filler on structural and physico-mechanical properties was evaluated. Among all modified series of PUR composites, the greatest improvement in physico-mechanical performances was observed for PUR composites reinforced with 1 wt % of the coir-fiber filler. For example, on the addition of 1 wt % of coir-fiber filler, the compression strength was improved by 23%, while the flexural strength increased by 9%. Similar dependence was observed in the case of dynamic-mechanical properties—on the addition of 1 wt % of the filler, the value of glass transition temperature increased from 149 °C to 178 °C, while the value of storage modulus increased by ~80%. It was found that PUR composites reinforced with coir-fiber filler were characterized by better mechanical performances after the UV-aging.

scholarly journals Analysis of PLA Composite Filaments Reinforced with Lignin and Polymerised-Lignin-Treated NFC

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2174
Author(s):  
Diana Gregor-Svetec ◽  
Mirjam Leskovšek ◽  
Blaž Leskovar ◽  
Urška Stanković Elesini ◽  
Urška Vrabič-Brodnjak
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Glassy State ◽  
Nanofibrillated Cellulose ◽  
Dynamic Mechanical Properties ◽  
Initial Modulus ◽  
Surface Modified ◽  
Scanning Electron

Polylactic acid (PLA) is one of the most suitable materials for 3D printing. Blending with nanoparticles improves some of its properties, broadening its application possibilities. The article presents a study of composite PLA matrix filaments with added unmodified and lignin/polymerised lignin surface-modified nanofibrillated cellulose (NFC). The influence of untreated and surface-modified NFC on morphological, mechanical, technological, infrared spectroscopic, and dynamic mechanical properties was evaluated for different groups of samples. As determined by the stereo and scanning electron microscopy, the unmodified and surface-modified NFCs with lignin and polymerised lignin were present in the form of plate-shaped agglomerates. The addition of NFC slightly reduced the filaments’ tensile strength, stretchability, and ability to absorb energy, while in contrast, the initial modulus slightly improved. By adding NFC to the PLA matrix, the bending storage modulus (E’) decreased slightly at lower temperatures, especially in the PLA samples with 3 wt% and 5 wt% NFC. When NFC was modified with lignin and polymerised lignin, an increase in E’ was noticed, especially in the glassy state.

Mechanical properties of low-density paper

2020 ◽  
Vol 35 (1) ◽  
pp. 61-70
Author(s):  
Na Young Park ◽  
Young Chan Ko ◽  
Lili Melani ◽  
Hyoung Jin Kim
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Structural Change ◽  
Tensile Testing ◽  
Tensile Modulus ◽  
Gauge Length ◽  
Efficiency Factor ◽  
Low Density ◽  
Tensile Stiffness ◽  
Lower Tensile Strength

AbstractFor the mechanical properties of paper, tensile testing has been widely used. Among the tensile properties, the tensile stiffness has been used to determine the softness of low-density paper. The lower tensile stiffness, the greater softness of paper. Because the elastic region may not be clearly defined in a load-elongation curve, it is suggested to use the tensile modulus which is defined as the slope between the two points in the curve. The two points which provide the best correlation with subjective softness evaluation should be selected. Low-density paper has a much lower tensile strength, but much larger elongation at the break. It undergoes a continuous structural change during mechanical testing. The degree of the structural change should depend on tensile conditions such as the sample size, the gauge length, and the rate of elongation. For low-density paper, the tensile modulus and the tensile strength should be independent of each other. The structure efficiency factor (SEF) is defined as a ratio of the tensile strength to the tensile modulus and it may be used a guideline in developing superior low-density paper products.

Effect of Castor Oil Impregnation on the Physical and Mechanical Properties of Bacterial Cellulose

2012 ◽  
Vol 3 (1) ◽  
pp. 13-26
Author(s):  
Myrtha Karina ◽  
Lucia Indrarti ◽  
Rike Yudianti ◽  
Indriyati
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Bacterial Cellulose ◽  
Young’S Modulus ◽  
Castor Oil ◽  
Young's Modulus ◽  
Physical And Mechanical Properties ◽  
Scanning Electron Micrographs ◽  
Elongation At Break ◽  
Acetone Water

The effect of castor oil on the physical and mechanical properties of bacterial cellulose is described. Bacterial cellulose (BC) was impregnated with 0.5–2% (w/v) castor oil (CO) in acetone–water, providing BCCO films. Scanning electron micrographs revealed that the castor oil penetrated the pores of the bacterial cellulose, resulting in a smoother morphology and enhanced hydrophilicity. Castor oil caused a slight change in crystallinity indices and resulted in reduced tensile strength and Young's modulus but increased elongation at break. A significant reduction in tensile strength and Young's modulus was achieved in BCCO films with 2% castor oil, and there was an improvement in elongation at break and hydrophilicity. Impregnation with castor oil, a biodegradable and safe plasticiser, resulted in less rigid and more ductile composites.

A new genus and four new species of millipedes from Tasmania, Australia (Diplopoda: Polydesmida: Dalodesmidae), with notes on male leg setae in some Tasmanian dalodesmids

Zootaxa ◽  
2004 ◽  
Vol 558 (1) ◽  
pp. 1 ◽  
Author(s):  
ROBERT MESIBOV
Keyword(s):  
New Species ◽  
Electron Micrographs ◽  
Type Species ◽  
New Genus ◽  
Scanning Electron Micrographs ◽  
Scanning Electron

Bromodesmus catrionae n. gen., n. sp. (type species), B. militaris n. sp., B. riparius n. sp. and B. rufus n. sp. are described. The new genus is characterized by greatly reduced paranota and a gonopod telopodite expanded at the distal end into a posteriorly concave hood fringed with teeth; the hood partly protects a long, curved, acutely pointed solenomerite. Male leg setation in the type species of six Tasmanian dalodesmid genera is briefly discussed and illustrated with scanning electron micrographs. The sphaerotrichome shaft is sharply pointed in Atrophotergum; gently tapered in Dasystigma, Lissodesmus and Tasmanodesmus; expanded at the tip in Bromodesmus; and entirely absent in Gasterogramma. Tips of the setae forming the dense ventral brush on male podomeres are gently tapered in Dasystigma and Lissodesmus, truncated in Gasterogramma, expanded in Bromodesmus and forked in Tasmanodesmus.

The ultrastructure of the epidermis of the redia and cercaria of Parorchis acanthus, Nicoll. A study by scanning and transmission electron-microscopy

Parasitology ◽  
1971 ◽  
Vol 62 (3) ◽  
pp. 479-488 ◽  
Author(s):  
Gwendolen Rees
Keyword(s):  
Electron Micrographs ◽  
Technical Assistance ◽  
Ventral Surface ◽  
The Body ◽  
Muscle Fibres ◽  
Scanning Electron Micrographs ◽  
Large Area ◽  
Transmission Electron ◽  
Parorchis Acanthus ◽  
Scanning Electron

Scanning electron-micrographs have shown the covering of microvilli on the surface of the redia of Parorchis acanthus. In the contracted state the elongated microvilli with bulbous extremities seen in the surface grooves may be the result of compression. The surface of the epidermis of the cercaria is smooth on a large area of the ventral surface and lattice-like with microvilli, laterally, anteriorly, dorsally and on the tail. The spines on the body can be withdrawn into sheaths by the contraction of muscle fibres inserted into the basement lamina below each spine.I would like to express my sincere gratitude to Dr I. ap Gwynn of this department for preparing the scanning electron-micrographs and the School of Engineering Science, University of North Wales, Bangor for the use of their stereoscan. I should also like to thank Mr M. C. Bibby for technical assistance and Professor E. G. Gray and Dr W. Sinclair for assistance with the transmission electron-micrographs.

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