scholarly journals Determination of Mean Intrinsic Flexural Strength and Coupling Factor of Natural Fiber Reinforcement in Polylactic Acid Biocomposites

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1736 ◽  
Author(s):  
Tarrés ◽  
Oliver-Ortega ◽  
Espinach ◽  
Mutjé ◽  
Delgado-Aguilar ◽  
...  

This paper is focused on the flexural properties of bleached kraft softwood fibers, bio-based, biodegradable, and a globally available reinforcement commonly used in papermaking, of reinforced polylactic acid (PLA) composites. The matrix, polylactic acid, is also a bio-based and biodegradable polymer. Flexural properties of composites incorporating percentages of reinforcement ranging from 15 to 30 wt % were measured and discussed. Another objective was to evaluate the strength of the interface between the matrix and the reinforcements, using the rule of mixtures to determine the coupling factor. Nonetheless, this rule of mixtures presents two unknowns, the coupling factor and the intrinsic flexural strength of the reinforcement. Hence, applying a ratio between the tensile and flexural intrinsic strengths and a defined fiber tensile and flexural strength factors, derived from the rule of mixtures is proposed. The literature lacks a precise evaluation of the intrinsic tensile strength of the reinforcements. In order to obtain such intrinsic tensile strength, we used the Kelly and Tyson modified equation as well as the solution provided by Bowyer and Bader. Finally, we were able to characterize the intrinsic flexural strengths of the fibers when used as reinforcement of polylactic acid.


2021 ◽  
pp. 152808372110199
Author(s):  
HT Sreenivas ◽  
N Krishnamurthy ◽  
MS Murali ◽  
GR Arpitha

The current study investigates on development of hybrid composite with Kenaf/Kevlar as reinforcement and unsaturated Polyester as the matrix considering stacking sequence, the orientation of fabric and twill 2x2 weave of the Kenaf fabric in particular. Five laminates (L1, L2, L3, L4, and L5) were developed by stacking the lamina's one over the other with the matrix and then cured in an autoclave. The laminates were subjected to experimental investigation to evaluate mechanical properties such as tensile strength, flexural strength, hardness, and impact strength. Results indicate that L5 shows good flexural strength and modulus, high hardness, and good impact strength, whereas L4 indicates the best tensile strength and tensile modulus. To summarize, the hybridization resulted in an average of 30% increased mechanical property for Laminate L5. The effect of stacking in L5 has a significant impact on the property of the composite. The results of the study were mainly focused on minimizing the use of synthetic fiber and replacing it with natural fiber. SEM analysis was performed on fractured surfaces of specimens which revealed that the failure of the laminated composite is due to poor interfacial bonding among fiber and matrix. Overall, the composite obtained from the combination of Kenaf and Kevlar fabrics had the best balance of properties finds appropriate application for car bumpers, fenders, boat hull, turbine blade etc.



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Taslima Ahmed Tamanna ◽  
Shah Alimuzzaman Belal ◽  
Mohammad Abul Hasan Shibly ◽  
Ayub Nabi Khan

AbstractThis study deals with the determination of new natural fibers extracted from the Corypha taliera fruit (CTF) and its characteristics were reported for the potential alternative of harmful synthetic fiber. The physical, chemical, mechanical, thermal, and morphological characteristics were investigated for CTF fibers. X-ray diffraction and chemical composition characterization ensured a higher amount of cellulose (55.1 wt%) content and crystallinity (62.5%) in the CTF fiber. The FTIR analysis ensured the different functional groups of cellulose, hemicellulose, and lignin present in the fiber. The Scherrer’s equation was used to determine crystallite size 1.45 nm. The mean diameter, specific density, and linear density of the CTF fiber were found (average) 131 μm, 0.86 g/cc, and 43 Tex, respectively. The maximum tensile strength was obtained 53.55 MPa for GL 20 mm and Young’s modulus 572.21 MPa for GL 30 mm. The required energy at break was recorded during the tensile strength experiment from the tensile strength tester and the average values for GL 20 mm and GL 30 mm are 0.05381 J and 0.08968 J, respectively. The thermal analysis ensured the thermal sustainability of CTF fiber up to 230 °C. Entirely the aforementioned outcomes ensured that the new CTF fiber is the expected reinforcement to the fiber-reinforced composite materials.



BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7954-7964
Author(s):  
Diego Gomez-Maldonado ◽  
Maria Soledad Peresin ◽  
Christina Verdi ◽  
Guillermo Velarde ◽  
Daniel Saloni

As the additive manufacturing process gains worldwide importance, the need for bio-based materials, especially for in-home polymeric use, also increases. This work aims to develop a composite of polylactic acid (PLA) and nanofibrillated cellulose (NFC) as a sustainable approach to reinforce the currently commercially available PLA. The studied materials were composites with 5 and 10% NFC that were blended and extruded. Mechanical, structural, and thermal characterization was made before its use for 3D printing. It was found that the inclusion of 10% NFC increased the modulus of elasticity in the filaments from 2.92 to 3.36 GPa. However, a small decrease in tensile strength was observed from 55.7 to 50.8 MPa, which was possibly due to the formation of NFC aggregates in the matrix. This work shows the potential of using PLA mixed with NFC for additive manufacturing.



2013 ◽  
Vol 681 ◽  
pp. 256-259
Author(s):  
Xiu Qi Liu ◽  
He Qin Xing ◽  
Li Li Zhao ◽  
Dan Wang

In our study, a new kind of foam composite was prepared by melt blending with PVC as the matrix and carbon black (CB) as the filler, the standard-spline was made in the dumbbell system prototype. Tensile strength and elongation at break were measured at 25°C。When the CB was added greater than 2.0%, with the increase of CB added, the determination of sample mechanical index began to decline, when the CB content was greater than 9%, tensile strength and elongation at break of the composites remained basically unchanged.



2018 ◽  
Vol 81 (1) ◽  
Author(s):  
Nik Alnur Auli Nik Yusuf ◽  
Mohammad Khairul Azhar Abdul Razab ◽  
Mohamad Bashree Abu Bakar ◽  
Khor Jia Yen ◽  
Chee Wing Tung ◽  
...  

This study summarizes the research on organic fillers, where eggshells were used as the reinforcement and banana peels as the matrix in the manufacturing of biocomposite thin film. Banana peel fibers exhibit a good characteristic of renewable material for the substitution of cement-based composites. However, biocomposite properties are limited by the poor adhesion between natural fiber interface and polymer matrix, which can be improved by chemical modification of fibers. In this research, banana peels were subjected to silane treatment. Biocomposite thin film manufacturing processes were carried out using blending and hand lay-up techniques with various concentrations of epoxy/waste banana peels/eggshell filler (EWE) ratios (EWE 0%, EWE 5%, and EWE 10%). X-ray diffraction (XRD), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and thickness swelling test were conducted on silane-treated and untreated banana peel biocomposite samples. In XRD analysis, it was found that EWE 10% sample had the highest crystallinity compared to EWE 0% and EWE 5%, and silane-treated samples had higher crystallinity than untreated samples.  For FTIR test, lignin component was removed in silane treatment based on the changes of IR peak characteristic where the new bonds (-Si-O-C-, -Si-O-Si-, and -Si-C-) were found in treated samples. Besides, TGA results showed that the thermal stability of silane-treated samples was improved significantly with the increase of eggshell filler percentage, which was proven by the decrease in the decomposition stage. In thickness swelling test, the samples achieved higher swelling percentage as the percentage of eggshell filler increased. However, the decrease of 5–6% in thickness swelling of treated samples was possibly offset by the enhancement in fiber/matrix interfacial adhesion. 



2001 ◽  
Vol 9 (5) ◽  
pp. 333-338 ◽  
Author(s):  
Mitsuhiro Shibata ◽  
Retsu Makino ◽  
Ryutoku Yosomiya ◽  
Hiroyuku Takeishi

Poly(butylene succinate) composites reinforced with short sisal fibre were prepared by melt mixing and subsequent injection moulding. The influence of fibre length, fibre content and the surface treatment of the natural fibres on the mechanical properties of the composites were evaluated. Regarding fibre length, the tensile and flexural properties of the composites had maxima at a fibre length of about 5 mm. The flexural and tensile moduli of the composites increased with increasing fibre content. Although the tensile strength hardly changed, the flexural strength increased up to a fibre content of 10 wt%. The dynamic mechanical analysis of the composites showed that the storage moduli at above ca.-16°C (corresponding to the glass transition temperature of the matrix) increased with increasing fibre content.



2013 ◽  
Vol 718-720 ◽  
pp. 63-68 ◽  
Author(s):  
Raja R. Niranjan ◽  
S. Junaid Kokan ◽  
R. Sathya Narayanan ◽  
S. Rajesh ◽  
V.M. Manickavasagam ◽  
...  

The natural fibre composite materials are nowadays playing a vital role in replacing the conventional and synthetic materials for industrial applications. This paper proposes a natural fiber composite made of Abaca fibre as reinforcing agent with Epoxy resin as the matrix, manufactured using Hand Lay-up method. Glass Fiber Reinforced Plastics (woven rovings) are used to improve the surface finish and impart more strength and stiffness to natural fibers. In this work, the fibers are arranged in alternative layers of abaca in horizontal and vertical orientation. The mechanical properties of the composite are determined by testing the samples for tensile and flexural strength. It is observed that the tensile strength of the composite material is dependent on the strength of the natural fiber and also on the interfacial adhesion between the reinforcement and the matrix. The composite is developed for automobile dashboard/mudguard application. It may also be extended to biomedical, electronics and sports goods manufacturing. It can also be used in marine products due to excellent resistance of abaca to salt water damage since the tensile strength when it is wet.



2010 ◽  
Vol 24 (15n16) ◽  
pp. 2838-2843 ◽  
Author(s):  
KAZUYA OHKITA ◽  
HITOSHI TAKAGI

In recent years, from an environmental perspective, there has been increasing interest in the change to a sustainable society. The use of natural-fiber-reinforced biodegradable composites has been proposed as one solution. Bamboo is an often used renewable bio-resource; it has an inherent advantage of rapid growth. Polybutylene succinate ( PBS ), used as matrix resin, has biodegradable characteristics. This paper describes flexural properties of bamboo/ PBS composites prepared by injection molding. The following results were obtained. The flexural modulus was improved with increasing bamboo powder contents when the cylinder temperature of the injection molder was 140°C. However, the flexural strength showed the opposite tendency to be decreased with increasing bamboo powder contents. An SEM photomicrograph of the fracture surface for bamboo/ PBS composites showed typical fracture behavior of pull-out fibers without fiber fracture. Furthermore, there was no adhesion of PBS resin on the bamboo fiber surface. Processing conditions affected mechanical properties of bamboo/ PBS composites, imparting higher flexural strength and flexural modulus at high cylinder temperatures such as 180°C and 200°C.



2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Chern Chiet Eng ◽  
Nor Azowa Ibrahim ◽  
Norhazlin Zainuddin ◽  
Hidayah Ariffin ◽  
Wan Md. Zin Wan Yunus

Natural fiber as reinforcement filler in polymer composites is an attractive approach due to being fully biodegradable and cheap. However, incompatibility between hydrophilic natural fiber and hydrophobic polymer matrix restricts the application. The current studies focus on the effects of incorporation of silane treated OPMF into polylactic acid (PLA)/polycaprolactone (PCL)/nanoclay/OPMF hybrid composites. The composites were prepared by melt blending technique and characterize the composites with Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). FTIR spectra indicated that peak shifting occurs when silane treated OPMF was incorporated into hybrid composites. Based on mechanical properties results, incorporation of silane treated OPMF enhances the mechanical properties of unmodified OPMF hybrid composites with the enhancement of flexural and impact strength being 17.60% and 48.43%, respectively, at 10% fiber loading. TGA thermogram shows that incorporation of silane treated OPMF did not show increment in thermal properties of hybrid composites. SEM micrographs revealed that silane treated OPMF hybrid composites show good fiber/matrix adhesion as fiber is still embedded in the matrix and no cavity is present on the surface. Water absorption test shows that addition of less hydrophilic silane treated OPMF successfully reduces the water uptake of hybrid composites.



2011 ◽  
Vol 31 (6-7) ◽  
Author(s):  
Xiuju Zhang ◽  
Juncai Shen ◽  
Tingting Yang ◽  
Bihua Ye ◽  
Zhidan Lin ◽  
...  

Abstract In this study, waste cotton cloth (RC) was bonded with soluble starches as an adhesive, then dried, cut into particles and filled into polylactic acid (PLA) to achieve resource efficiency. The mechanical, thermal and crystallization properties of the composites were characterized. The results indicated that with the addition of RC, the tensile strength, impact strength and flexural strength of PLA composites improved. Also, the heat distortion temperatures increased slowly, indicating that RC filled into PLA can be turned back into useful items without the degradation of PLA composites. This is a good way to give direction to the resource utilization of waste clothing. The addition of RC could significantly reduce the spherulitic size of PLA.



Sign in / Sign up

Export Citation Format

Share Document