Recycling of polypropylene and curaua fiber-based ecocomposites: Effect of reprocessing on mechanical properties

Author(s):  
Sistanley Jones Lima Bispo ◽  
Raimundo Carlos Silverio Freire Júnior ◽  
Joelton Fonseca Barbosa ◽  
Camila Cruz da Silva ◽  
Elmo Thiago Lins Cöuras Ford

The polypropylene with load of reinforcement of curauá fiber (PP-curauá) is a compound developed to be applied in the process of injection of automotive plastic parts. Polypropylene composites reinforced with mineral fillers (talc) or glass fibers have been widely applied in this segment. However, natural fibers are an important alternative considering the aspects of sustainability, recyclability, abundance and low cost, when compared with glass fibers, and industrial talc. This study was prompted by the growing need for materials that meet the constant cycles of use, disposal and reuse, and avoid the harmful effects on the environment. The mechanical properties of a curaua fiber and polypropylene-based ecocomposite reprocessed one, three and five times were assessed, since reprocessing is known to change the strength of these materials. Pure polypropylene (0%) and ecocomposites with 10 and 30 wt% of fiber were submitted to tensile and three-point bending tests. The results showed that polypropylene ecocomposites with 30% curaua fibers exhibited a higher modulus of elasticity. Moreover, reprocessing did not significantly affect the ecocomposite properties, demonstrating their viability for reuse.

2012 ◽  
Vol 15 (3) ◽  
pp. 5-14
Author(s):  
Thanh Duy Tran ◽  
Tai Tan Dang

Composite materials are usually made with organic matrixes reinforced by synthetic fillers, such as carbon or glass fibers.... But the high cost and environmental awareness of the synthetic fibers has limited their application. Meanwhile, natural fibers have been very attractive because they have been low cost, low density, eco-friendly, available in high quantities, renewable, biodegradable and shown excellent mechanical properties. In this study, green composite materials were prepared by using unsaturated polyester resins and bamboo fibers. The fibers were previously modified by chemical treatment and inserted into matrix in the role of the reinforcement. Some factors effecting to properties of products showed more advantages than modifier content were studied meticulously. As a result, composite products showed more advantages than neat polymer. For example, it does not only improve significantly mechanical properties but also becomes cheaper and friendlier with environment.


Author(s):  
Amany Micheal ◽  
Yehia Bahei-El-Din ◽  
Mahmoud E. Abd El-Latief

Abstract When inevitable, failure in composite laminates is preferred to occur gracefully to avoid loss of property and possibly life. While the inherent inhomogeneity leads to slow dissipation of damage-related energy, overall failure is fiber-dominated and occurs in a rather brittle manner. Multidirectional plies usually give a more ductile response. Additionally, stiffness and strength as well as cost are important factors to consider in designing composite laminates. It is hence desirable to optimize for high mechanical properties and low cost while keeping graceful failure. Designing composite laminates with hybrid systems and layups, which permit gradual damage energy dissipation, are two ways proposed in this work to optimize for mechanical properties while avoiding catastrophic failure. In the hybrid system design, combining the less expensive glass reinforced plies with carbon reinforced plies offers a cost-effective product, marginal mechanical properties change and ductile profile upon failure. Hybrid glass/carbon composite laminates subjected to three-point bending showed strain to failure which is double that measured for carbon composite specimens, without affecting the ultimate load. Energy dissipation mechanisms were also created by building laminates which were intentionally made discontinuous by introducing cuts in the fibers of the interior plies. This created a longer path for damage before cutting through the next ply resulting in double failure strain with marginal reduction in load. The effect of fiber discontinuity in terms of spacing and distribution are among the factors considered.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 782 ◽  
Author(s):  
Wei Wang ◽  
Xiaomin Guo ◽  
Defang Zhao ◽  
Liu Liu ◽  
Ruiyun Zhang ◽  
...  

Environmentally sound composites reinforced with natural fibers or particles interest many researchers and engineers due to their great potential to substitute the traditional composites reinforced with glass fibers. However, the sensitivity of natural fiber-reinforced composites to water has limited their applications. In this paper, wood powder-reinforced polypropylene composites (WPCs) with various wood content were prepared and subjected to water absorption tests to study the water absorption procedure and the effect of water absorbed in the specimens on the mechanical properties. Water soaking tests were carried out by immersion of composite specimens in a container of distilled water maintained at three different temperatures, 23, 60 and 80 °C. The results showed that the moisture absorption content was related to wood powder percentage and they had a positive relationship. The transfer process of water molecules in the sample was found to follow the Fickian model and the diffusion constant increased with elevated water temperature. In addition, tensile and bending tests of both dry and wet composite samples were conducted and the results indicated that water absorbed in composite specimens degraded their mechanical properties. The tensile strength and modulus of the composites reinforced with 15, 30, 45 wt % wood powder decreased by 5.79%, 17.2%, 32.06% and 25.31%, 33.6%, 47.3% respectively, compared with their corresponding dry specimens. The flexural strength and modulus of the composite samples exhibited a similar result. Furthermore, dynamic mechanical analysis (DMA) also confirmed that the detrimental effect of water molecules on the composite specimens.


2020 ◽  
pp. 002199832097519
Author(s):  
Fatma Naiiri ◽  
Allègue Lamis ◽  
Salem Mehdi ◽  
Zitoune Redouane ◽  
Zidi Mondher

Natural fibers are increasingly used in composites because of their low cost and good mechanical properties. Cement reinforced with natural fibersis contemplates as a new generation of construction materials with superior mechanical and thermal performance. This study of three sizes’effect of Doum palm fiber explores the mortar’s behavior reinforced with different fiber ratio. The aim is to determine the optimal addition to improve mechanical and thermal properties of natural fiber reinforced cements. Physical, mechanical and thermal properties of composite are examined. Tensile properties of Doum fibers are verified to determine their potential as reinforced material. Findings prove that the use of alkali-treated Doum fiber as reinforcement in cement mortar composite leads to the upgrading of the mechanical properties including thermo-physical properties against composites reinforced with raw fibers and control cement mortars. While, the compression and flexural strength of the cement mortar reinforced with alkali-treated Doum fiber with diameter 0.3 mm (CT3) are metered to be 11.11 MPa, 5.22 MPa, respectively for fiber content 0.5%. Additionally, based on thermo-physical tests, it is assessed that the thermal conductivity and diffusivity decrease for cement mortar reinforced with Doum fiber with diameter 0.2 mm (CT2).


2018 ◽  
Vol 25 (6) ◽  
pp. 1039-1058 ◽  
Author(s):  
Sumit Das Lala ◽  
Ashish B. Deoghare ◽  
Sushovan Chatterjee

AbstractThe inherent properties of bio-composites such as biodegradability, environment friendly, low cost of production, high strength and durability make them a suitable replacement to traditional materials such as glass and nylon. Bio-polymers are finding wide applications due to their intrinsic properties such as low density, low thermal conductivity, corrosion resistance and ease of manufacturing complex shapes. This paper aims toward a comprehensive study on polymer bio-composites. The review mainly focuses on types of reinforcements such as natural fibers, seed shells, animal fibers, cellulose, bio-polymers, bio-chemicals and bioceramics which enhance the mechanical properties, such as tensile strength, compressive strength, flexural strength, Young’s modulus and creep behavior, of the composites. The pertinent study carried out in this review explores an enormous potentiality of the composites toward a wide variety of applications.


2014 ◽  
Vol 69 (6) ◽  
Author(s):  
A. Mataram

Polypropylene (PP) including a type of plastic which ranks second on the most number of types of plastic waste after the type of High Density Polyethylene (HDPE). Glass fibers have superior mechanical properties of natural fibers. Because it has good mechanical properties, glass fibers currently plays an important role in the use of composite reinforcement. Mechanical properties of glass fiber owned and PP waste in environmental conditions that more conditions, it can be utilized as a composite reinforcement and matrix materials. This research was conducted by of injection molding method. The comparison between the volume fraction of the glass fiber matrix of type PP plastic waste with variation 0% fibers 100% matrixs, 10% fibers 90% matrixs, 20% fibers 80% matrixs, 30% fibers 70% matrixs, 40% fibers 60% matrixs, and 50 % fibers 50% matrixs. The optimum conditions obtained in this study was the comparison of variation occurs in 50% fibers volume fractions of 50% matrixs were: tensile stress was 24.30 N/mm2, tensile strain was 13.60%.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Jong Sung Won ◽  
Ji Eun Lee ◽  
Da Young Jin ◽  
Seung Goo Lee

The effective utilization of original natural fibers as indispensable components in natural resins for developing novel, low-cost, eco-friendly biocomposites is one of the most rapidly emerging fields of research in fiber-reinforced composite. The objective of this study is to investigate the interfacial adhesion properties, water absorption, biodegradation properties, and mechanical properties of the kenaf/soy protein isolate- (SPI-) PVA composite. Experimental results showed that 20 wt% poly (vinyl alcohol) (PVA) and 8 wt% glutaraldehyde (GA) created optimum conditions for the consolidation of the composite. The increase of interfacial shear strength enhanced the composites flexural and tensile strength of the kenaf/SPI-PVA composite. The kenaf/SPI-PVA mechanical properties of the composite also increased with the content of cross-linking agent. Results of the biodegradation test indicated that the degradation time of the composite could be controlled by the cross-linking agent. The degradation rate of the kenaf/SPI-PVA composite with the cross-linking agent was lower than that of the composite without the cross-linking agent.


2014 ◽  
Vol 984-985 ◽  
pp. 285-290
Author(s):  
K. Hari Ram ◽  
R. Edwin Raj

Polymer composites reinforced with natural fibers have been developed in recent years, showing significant potential for various engineering applications due to their inherent sustainability, low cost, light weight and comparable mechanical strength. Sisal is a natural fiber extracted from leaves of Agave Sisalana plants and substituted for natural glass fiber. Six different combinations of specimens were prepared with sisal, sisal-glass and glass fibers with epoxy as matrix at two different fiber orientation of 0-90° and ±45°. Mechanical characterization such as tensile, flexural and impact testing were done to analyze their mechanical strength. It is found that the hybrid composite sisal-glass-epoxy has better and comparable mechanical properties with conventional glass-epoxy composite and thus provides a viable, sustainable alternate polymer composite.


2014 ◽  
Vol 775-776 ◽  
pp. 325-329 ◽  
Author(s):  
Sergio Neves Monteiro ◽  
Frederico Muylaert Margem ◽  
Noan Tonini Simonassi ◽  
Rômulo Leite Loiola ◽  
Michel Picanço Oliveira

Natural fibers obtained from plants are being investigated as possible engineering materials with application in polymer composite reinforcement. For instance, the lignocellulosic fibers extracted from the leaves of the curaua plant (Ananas erectifolius) display a reinforcement potential owing to their relatively high strength. However, the curaua fiber has a poor adhesion with the polymeric matrix. In order to understand the curaua fiber interaction with a polymer matrix, the physical and chemical characteristics need to be evaluated. Among these characteristics, the Fourier transform infrared spectroscopy (FTIR) provides relevant information about the functional molecular groups and their possible interaction. Therefore, the objective of the present work was to analyze the FTIR of curaua fibers by means of transmittance spectrum obtained in the FTIR method with a 60o angle. The results showed peaks corresponding to specific molecular interaction that are discussed and compared to other results.


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