scholarly journals Enhancement of Static and Fatigue Strength of Short Sisal Fiber Biocomposites by Low Fraction Nanotubes

2021 ◽  
Author(s):  
A. Pantano ◽  
F. Bongiorno ◽  
G. Marannano ◽  
B. Zuccarello
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Low Cost ◽  
Short Fiber ◽  
Fatigue Tests ◽  
Sisal Fiber ◽  
Molding Process ◽  
Matrix Adhesion ◽  
Fiber Matrix ◽  
Damage Processes

AbstractThanks to good mechanical performances, high availability, low cost and low weight, the agave sisalana fiber allows to obtain biocomposites characterised by high specific properties, potentially very attractive for the replacement of synthetic materials in various industrial fields. Unfortunately, due to the low strength versus transversal damage processes mainly related to the matrix brittleness and/or to the low fiber/matrix adhesion, the tensile performance of random short fiber biocomposites are quite low, and to date most of the fiber treatments proposed in literature to improve the fiber-matrix adhesion, have not led to very satisfactory results. In order to overcome such a drawback, this work in turn proposes the proper introduction of low fractions carbon nanotubes to activate advantageous improvements in matrix toughness as well as fiber-matrix bridging effects, that can both lead to appreciable increments of the tensile strength.Systematic experimental static and fatigue tests performed on high quality biocomposites obtained by an optimized compression molding process, have shown that the introduction of 1% of carbon nanotubes is sufficient to gives significant improvement in both stiffness and static tensile strength, respectively by approximately 28% and 30%. Furthermore, toughening the biocomposite with 1% of nanotubes results in an appreciable enhancement in lifetime of at least 3 orders of magnitude. Biocomposites with 2% of CNTs show instead more limited improvement of 13% in stiffness, 6% in strength and 150% in lifetime. Also, a thorough analysis of the damage processes by SEM micrographs, as well as of the main fatigue data, has allowed to determine the model that can be used to predict the fatigue performance of such biocomposites.

scholarly journals Thermo-Mechanical and Morphological Properties of Polymer Composites Reinforced by Natural Fibers Derived from Wet Blue Leather Wastes: A Comparative Study

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1837
Author(s):  
Alessandro Nanni ◽  
Mariafederica Parisi ◽  
Martino Colonna ◽  
Massimo Messori
Keyword(s):  
Tensile Strength ◽  
Polymer Matrix ◽  
Thermoplastic Polyurethane ◽  
Young Modulus ◽  
Morphological Properties ◽  
Poly Lactic Acid ◽  
Matrix Adhesion ◽  
The Poor ◽  
Leather Wastes ◽  
Fiber Matrix

The present work investigated the possibility to use wet blue (WB) leather wastes as natural reinforcing fibers within different polymer matrices. After their preparation and characterization, WB fibers were melt-mixed at 10 wt.% with poly(lactic acid) (PLA), polyamide 12 (PA12), thermoplastic elastomer (TPE), and thermoplastic polyurethane (TPU), and the obtained samples were subjected to rheological, thermal, thermo-mechanical, and viscoelastic analyses. In parallel, morphological properties such as fiber distribution and dispersion, fiber–matrix adhesion, and fiber exfoliation phenomena were analyzed through a scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS) to evaluate the relationship between the compounding process, mechanical responses, and morphological parameters. The PLA-based composite exhibited the best results since the Young modulus (+18%), tensile strength (+1.5%), impact (+10%), and creep (+5%) resistance were simultaneously enhanced by the addition of WB fibers, which were well dispersed and distributed in and significantly branched and interlocked with the polymer matrix. PA12- and TPU-based formulations showed a positive behavior (around +47% of the Young modulus and +40% of creep resistance) even if the not-optimal fiber–matrix adhesion and/or the poor de-fibration of WB slightly lowered the tensile strength and elongation at break. Finally, the TPE-based sample exhibited the worst performance because of the poor affinity between hydrophilic WB fibers and the hydrophobic polymer matrix.

A low-cost, low-fiber-breakage, injection molding process for long sisal fiber reinforced polypropylene

2004 ◽  
Vol 44 (9) ◽  
pp. 1766-1772 ◽  
Author(s):  
L. M. Arzondo ◽  
A. Vazquez ◽  
J. M. Carella ◽  
J. M. Pastor
Keyword(s):  
Injection Molding ◽  
Low Cost ◽  
Sisal Fiber ◽  
Injection Molding Process ◽  
Fiber Breakage ◽  
Fiber Reinforced ◽  
Molding Process

Short-Fiber-Reinforced Elastomer Composites

1977 ◽  
Vol 50 (5) ◽  
pp. 945-958 ◽  
Author(s):  
J. E. O'Connor
Keyword(s):  
Fiber Type ◽  
Cellulose Fibers ◽  
Short Fiber ◽  
Bonding Agents ◽  
Fiber Dispersion ◽  
Adhesion Promoters ◽  
Fiber Aspect Ratio ◽  
Matrix Adhesion ◽  
Glass Carbon ◽  
Fiber Matrix

Abstract The reinforcement of elastomers with short fibers results in composites with a wide variety of properties. The performance and properties are a function of fiber type, fiber content, fiber aspect ratio, fiber orientation, fiber dispersion, fiber-matrix adhesion, processing methods, and properties of the elastomer matrix. A composite with almost any desired property can be obtained by manipulation of these parameters. Of the five fibers studied in this work, glass and carbon are the poorest for increasing mechanical properties. The cellulose, aramid, and nylon fibers all reinforce elastomers to give composites of approximately the same magnitude in properties. Alignment of reinforcing fibers by milling creates a significant anisotropy in the composite properties. The degree of fiber alignment is best for glass, carbon, and cellulose fibers. The uniformity of fiber dispersion is again best for glass, carbon, and cellulose fibers. Aramid and nylon fibers tend to clump together and do not disperse easily. Fiber-to-matrix adhesion is a problem. No evidence of consistently good fiber-matrix adhesion is observed except for the precoated cellulose fibers. The interaction between fiber and elastomer can only improve with a coating or sizing that is compatible with both the fiber and its matrix. Adhesion-promoting bonding agents also improve fiber-matrix adhesion. However, each fiber and/or elastomer may be influenced differently by a bonding agent. Adhesion promoters specific to the type of composite being prepared must be sought in order to obtain optimum properties.

Mechanical Behavior of Environment-Friendly Green Composites Fabricated with Starch-Based Resin and Short MAO Fibers

2010 ◽  
Vol 452-453 ◽  
pp. 313-316 ◽  
Author(s):  
Hitoshi Takagi ◽  
Anil N. Netravali
Keyword(s):  
Tensile Strength ◽  
Surface Treatment ◽  
Fiber Length ◽  
Alkali Treatment ◽  
Short Fiber ◽  
Interface Fracture ◽  
Green Composites ◽  
Weight Content ◽  
Fiber Matrix ◽  
Interfacial Adhesion Strength

Environmentally friendly green composites were fabricated from a natural cellulosic fiber (MAO fiber) and a biodegradable starch-based resin through hot-pressing. The effects of fiber length and alkali surface treatment on mechanical properties of the green composites were investigated. Fiber lengths of 2.5, 5, 10, and 20 mm were used and fiber weight content was adjusted to 56%, to obtain short fiber composites with random orientation. Ultimate tensile strength increased with increasing the fiber length up to 10 mm and remained almost constant for further increases in fiber length. Fracture strain for the composites fabricated with fiber length of 2.5 mm showed the smallest value of approximately 2 %, which is less than that of MAO fiber. This might be attributed to the debonding at the fiber/matrix interface. Fracture strains of the green composites with fibers longer than 2.5 mm were almost constant and were comparable to the fracture strains of MAO fiber indicating that the fracture properties were controlled by the fiber. Both tensile strength and Young’s modulus values were increased by alkali surface-treatment for MAO fibers. The reason for this behavior seems that alkali treatment increases the fiber/matrix interfacial adhesion strength primarily by removing lignin.

Study on Temperature-Dependent Tensile Strength of Short-Fiber-Reinforced Elastomer Matrix Composites

2008 ◽  
Vol 44-46 ◽  
pp. 97-104 ◽  
Author(s):  
D.S. Zhu ◽  
Bo Qin Gu ◽  
Ye Chen
Keyword(s):  
Tensile Strength ◽  
Fiber Length ◽  
Volume Fraction ◽  
Short Fiber ◽  
Tensile Fracture ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Temperature Dependent ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

The temperature-dependent tensile strength is an important indicator used to evaluate combination property of short-fiber-reinforced elastomer matrix composite. Some short-fiber-reinforced elastomer matrix composites are manufactured in the molding preparation process, and the tensile tests of fiber, matrix and the composites are carried out at different temperatures. The fiber length and orientation distributions are statistically analyzed. The influence of temperature on the micromechanical stress distribution and transfer in the composite is investigated, and the thermal stresses in the fiber, matrix and fiber-matrix interface are obtained. Based on the theory of micromechanical stress distribution and transfer of the fibrous composite, the mixture law is modified, and a model for predicting the temperature-dependent tensile strength of this kind of composite is developed. Moreover, the mechanism of the tensile fracture of the composite at various temperatures is discussed. Research indicates that the tensile strength is largely related to the temperature, mechanical performances of the main components of the composite and some microstructural parameters, such as short fiber aspect ratio, volume fraction and orientation distribution. The tensile strength of SFRE decreases with increasing temperature. The tensile strength increases with the increase of fiber length when the fiber length is no larger than critical fiber length. There exists a critical fiber volume fraction where the tensile strength of SFRE reaches the maximum. The tensile fracture of the composite depends largely on the temperature, the bond strength of fiber-matrix interface and the average length of reinforcing short fibers. The temperature-dependent tensile strengths predicted by the presented model are in good agreement with experimental data.

scholarly journals New Concept in Bioderived Composites: Biochar as Toughening Agent for Improving Performances and Durability of Agave-Based Epoxy Biocomposites

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 198
Author(s):  
Bernardo Zuccarello ◽  
Mattia Bartoli ◽  
Francesco Bongiorno ◽  
Carmelo Militello ◽  
Alberto Tagliaferro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Low Cost ◽  
Experimental Tests ◽  
Short Fiber ◽  
Molding Process ◽  
Environmental Friendliness ◽  
Synthetic Materials ◽  
The Matrix ◽  
Static Tensile

Biocomposites are increasingly used in the industry for the replacement of synthetic materials, thanks to their good mechanical properties, being lightweight, and having low cost. Unfortunately, in several potential fields of structural application their static strength and fatigue life are not high enough. For this reason, several chemical treatments on the fibers have been proposed in literature, although still without fully satisfactory results. To overcome this drawback, in this study we present a procedure based on the addition of a carbonaceous filler to a green epoxy matrix reinforced by Agave sisalana fibers. Among all carbon-based materials, biochar was selected for its environmental friendliness, along with its ability to improve the mechanical properties of polymers. Different percentages of biochar, 1, 2, and 4 wt %, were finely dispersed into the resin using a mixer and a sonicator, then a compression molding process coupled with an optimized thermomechanical cure process was used to produce a short fiber biocomposite with Vf = 35%. Systematic experimental tests have shown that the presence of biochar, in the amount 2 wt %, has significant effects on the matrix and fiber interphase, and leads to an increase of up to three orders of magnitude in the fatigue life, together with an appreciable improvement in static tensile strength.

Investigating the effects of liquid-plasma treatment on tensile strength of coir fibers and interfacial fiber-matrix adhesion of composites

2020 ◽  
Vol 183 ◽  
pp. 107722 ◽  
Author(s):  
Andi Erwin Eka Putra ◽  
Ilyas Renreng ◽  
Hairul Arsyad ◽  
Bakri Bakri
Keyword(s):  
Tensile Strength ◽  
Plasma Treatment ◽  
Matrix Adhesion ◽  
Coir Fibers ◽  
Fiber Matrix

Effect of fiber-matrix adhesion on the properties of short fiber reinforced ABS

1973 ◽  
Vol 13 (6) ◽  
pp. 409-414 ◽  
Author(s):  
William M. Speri ◽  
Charles F. Jenkins
Keyword(s):  
Short Fiber ◽  
Fiber Reinforced ◽  
Matrix Adhesion ◽  
Fiber Matrix

scholarly journals Functionalized multi-walled carbon nanotubes and hydroxyapatite nanorods reinforced with polypropylene for biomedical application

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fahad Saleem Ahmed Khan ◽  
N. M. Mubarak ◽  
Mohammad Khalid ◽  
Rashmi Walvekar ◽  
E. C. Abdullah ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Mechanical Characteristics ◽  
Biomedical Application ◽  
Thermal Study ◽  
Melt Compounding ◽  
Industry Applications ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
And Cartilage

AbstractModified multi-walled carbon nanotubes (f-MWCNTs) and hydroxyapatite nanorods (n-HA) were reinforced into polypropylene (PP) with the support of a melt compounding approach. Varying composition of f-MWCNTs (0.1–0.3 wt.%) and nHA (15–20 wt.%) were reinforced into PP, to obtain biocomposites of different compositions. The morphology, thermal and mechanical characteristics of PP/n-HA/f-MWCNTs were observed. Tensile studies reflected that the addition of f-MWCNTs is advantageous in improving the tensile strength of PP/n-HA nanocomposites but decreases its Young’s modulus significantly. Based on the thermal study, the f-MWCNTs and n-HA were known to be adequate to enhance PP’s thermal and dimensional stability. Furthermore, MTT studies proved that PP/n-HA/f-MWCNTs are biocompatible. Consequently, f-MWCNTs and n-HA reinforced into PP may be a promising nanocomposite in orthopedics industry applications such as the human subchondral bone i.e. patella and cartilage and fabricating certain light-loaded implants.

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