Polypropylene biocomposites reinforced with softwood, abaca, jute, and kenaf fibers

The potential application of green fibre based composite plate in retrofitting of structure is growing up in construction industry nowadays. The aim of this research was to develop high strength natural fibre based composite plates for the possible application in strengthening of reinforced concrete structure. The plates were fabricated using kenaf fibre, jute fibre and jute rope respectively. The fibres and rope were chemically treated using 6% NaOH solution to enhance the tensile strength of fabricated plates. In fabrication process, a special technique was applied to compact the treated and untreated fibres to obtain the highest tensile strength of composite plates. The physical and mechanical properties of the fabricated composite plates were then experimentally investigated. In general, results showed that the chemical treatments had an influence to enhance the tensile strength of the plates. The tensile strength of composite plates with treated kenaf fibre, jute fibre and jute rope were 137 MPa, 136 MPa and 113 MPa respectively. While those of untreated kenaf fibre, jute fibre and jute ropes were 131 MPa, 136 MPa and 110 MPa respectively. Kenaf and jute fibre composite plates had shown higher tensile strengths as compared to those of jute rope. The natural fibre composite plates were found to be linearly elastic in nature and had shown brittle failure. The moisture content and the water absorption of the plates with treated fibres were found to be lower as compared to those of untreated fibres. In terms of tensile strength of fabricated plates, kenaf, jute and jute rope composite plates could be used in retrofitting of structures.

Pineapple leaf fibre (PALF) was hybridized with kenaf fibre in order to achieve superior physical and flammability performance. The mixing effects of kenaf fibre and pineapple leaf fibre in phenolic composites are evaluated at various fibre ratios and investigated various physical properties such as density, void content water absorption, thickness swelling and flammability. Pure kenaf fibre composite showed lowest void content, water absorption and thickness swelling while pineapple leaf fibre revealed the opposite trend. After adding pineapple leaf fibre in kenaf composites, it absorbed more moisture and developed more void contents. Density of PALF composite was lower and kenaf fibre composite was highest but PALF/kenaf hybrid composite increased density with higher PALF. The flammability of hybrid composites were analysed by using UL-94 test method. Vertical and horizontal UL-94 test conducted to analyse fire resistance of composites from different angles. Phenolic resin is itself a fire resistant polymer and the percentage of polymer in all samples are fixed though ratios of both fibres pineapple leaf fibre and kenaf were change to analyse fire resistant of fibres and compatibility with polymers. The 70 % pineapple leaf fibre and 30 % kenaf fibre hybrid composites were very affective to improve the flammability of PALF/KF hybrid composites.

This study investigates the mechanical and thermal properties of biocomposite in relation to their hybridization. Compression moulding was utilised to produce hybrid biocomposites composed of polyester resin reinforced with kenaf, jute, and three distinct combinations of kenaf/jute fibers. To increase the bonding of kenaf and jute fibers with polyester resin, a 5 percent NaOH solution was administered to them. The following stacking sequences were used to manufacture a total of five different types of laminates: polyester resin 80 wt%/kenaf fiber 20 wt%, polyester resin 80 wt%/jute fiber 20 wt%), polyester resin 80 wt%/kenaf fiber 5 wt%/jute fiber 15 wt%, polyester resin 80 wt%/kenaf fiber 10 wt%/jute fiber 10 wt%, and polyester resin 80 wt%/kenaf fiber 15 wt%/jute fiber 5 wt%. In the mechanical and thermal tests, it was discovered that the polyester resin 80 wt%/jute fiber 20 wt% biocomposites had increased strength compared to the other hybrid biocomposites investigated.

This research investigates the physical and mechanical properties of hybrid composites made of epoxy reinforced by kenaf and flax natural fibers to investigate the hybridization influences of the composites. Pure and hybrid composites were fabricated using bi‐directional kenaf and flax fabrics at different stacking sequences utilizing the vacuum‐assisted resin infusion method. The pure and hybrid composites' physical properties, such as density, fiber volume fraction (FVF), water absorption capacity, and dimensional stability, were measured. The tests of tensile, flexural, interlaminar shear and fracture toughness (Mode II) were examined to determine the mechanical properties. The results revealed that density remained unchanged for the hybrid compared to pure kenaf/epoxy composites. The tensile, flexural, and interlaminar shear performance of flax/epoxy composite is improved by an increment of kenaf FVF in hybrid composites. The stacking sequence significantly affected the mechanical properties of hybrid composites. The highest tensile strength (59.8 MPa) was obtained for FK2 (alternative sequence of flax and kenaf fibers). However, FK3 (flax fiber located on the outer surfaces) had the highest interlaminar shear strength (12.5 MPa) and fracture toughness (3302.3 J/m2) among all tested hybrid composites. The highest water resistance was achieved for FK5 with the lowest thickness swelling.

Effect of waste tyre particles reinforcement on mechanical properties of jute and abaca fiber- epoxy hybrid composites with pre-treatment

5 - Rice husk and kenaf fiber reinforced polypropylene biocomposites

Purpose This study aims to evaluate the impact of heat treatment on mechanical properties by means of different mechanical measurement methods such as tensile strength and comparison between two results taken by the same test, experimental and 7D image analyses. Design/methodology/approach In this work, two different types of natural fibers, namely alfa and jute fibers, were used as reinforcing materials for the development of fiber-reinforced hybrid composites. Alfa fiber, due to its availability in the Laghouat region of Algeria, represents a good alternative for the development of an eco-responsible natural reinforcement for plastic composites. In this sub-Saharan region materials are subjected to very high temperatures that can easily reach 50°C and often more. For this reason, the composites of this study made with a weight fraction of 40% of either alfa or jute fibers were subjected to aging in an oven at a temperature of 50°C. A sampling was carried out at regular intervals, i.e. 0, 30 and 60 days. Findings There is a considerable change between the experimental results and the image analysis software from one element to another, being based on the behavior of each element relative to the other elements of the test piece, which results in a non-homogeneous behavior of the tensile curve. Originality/value This initial work highlights the superior potential of polyester composites reinforced with treated esparto fiber, suggests a novel methodology and provides a strong foundation for optimizing and modeling biosourced composite materials intended for thermally sensitive environments. Depending on the type of fiber and the treatment received, thermal aging can either strengthen or weaken specific mechanical directions, according to an analysis of aging-induced anisotropy that clearly shows the differences in the evolution of longitudinal and transverse performances. In order to supplement traditional testing, a sophisticated image analysis technique (7D) was used, which revealed local strain variations of up to ±25% that were not detectable using traditional methods. This demonstrates that in order to investigate composite materials with intricate microstructures, more sensitive measurement instruments are required.

The plastic industry is considered one of the most dynamic industries with the highest competitive projection in the country [1]. Thanks to the advances of this industry, new products have been developed with various applications at industrial, commercial, service levels, and society’s daily lives. Plastics are highly demanded their chemical and physical properties, versatility, and low cost. However, many challenges are arising from the growth in consumption and the dynamics of the plastics industry, such as the prices of raw materials, substitute products of plastic, the demands of consumers, government, and other interested parties with the impact of plastics on the environment during the different stages of their life cycle. Concerning the life cycle of the plastic products is especially determinant the post-consumption, where plastic waste presents a low percentage of recycling and a prolonged period of degradation, being a product questioned for its negative environmental implications. In this sense, companies in the sector must implement different strategies and tools to evaluate their environmental performance, considering the product life cycle. In the world, there are various government regulations for the responsible use of plastics. International methodologies focused on sustainable environmental management in the products, processes, and organizational level have also been developed, such as the product life cycle approach, reverse logistics, and the ISO 45001 standard. However, it is necessary to create objective and analytical methodologies for evaluating environmental management and reverse logistics that provide solutions for the plastic industry, helping companies comply with applicable legal requirements and standards, and supporting decision-making processes. Concerning the decision-making is a complex process given the complexity of the sector and the multiple criteria taken into account when evaluating and establishing improvement strategies. In the literature review, we found several studies with the application of a multicriteria combined approach focused on selecting plastic recycling methods, location of plastic processing centers, eco-design of plastic products, and selection of suppliers. Despite these considerations, the research-oriented on applying integrated methodologies for evaluating performance in the environmental management and reverse logistics in the plastic industry, under multiple criteria and uncertainty, are mostly limited and with the exciting potential of development. Therefore, this document presents a hybrid methodology for evaluating the performance in the environmental management and reverse logistics in the plastic industry by applying two techniques of Multi-criteria Decision Methods (MCDM) uses in environments under uncertainly. First, the fuzzy Analytic Hierarchy Process (FAHP) is applied to estimate the initial relative weights of criteria and sub-criteria. The fuzzy set theory is incorporated to represent the uncertainty in the judgments of decision-makers. Then, the Decision-making Trial and Evaluation Laboratory (DEMATEL) was used for evaluating the interdependences between criteria and sub-criteria. FAHP and DEMATEL are later combined for calculating the final criteria and sub-criteria weights under vagueness and interdependence. Subsequently, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was used to rank the companies of the plastic industry. Finally, we detect improvement opportunities for the companies of the plastic sector.

Kenaf fibre mat (KFM) reinforced polypropylene (PP) biocomposites have been prepared using sandwich structure and hot press moulding technique. To enhance the interfacial bonding between PP and kenaf fibre, KFM was chemically treated with two different chemicals which are 5% hydrogen peroxide and 2% silane. Fourier transform infrared (FTIR) was used to characterize the chemical constituents in both treated and untreated kenaf fibres. Universal tensile machine (UTM) was used to determine mechanical properties (tensile and flexural strength, tensile and flexural modulus) of both treated and untreated KFM-PP biocomposites. Water absorption test was also conducted in order to evaluate its water-resistance performance. The result shows that peroxide treatment demonstrated the highest performance in mechanical and water absorption properties compared to other chemical treatment. SEM morphological studies proved that almost all treated KFM showing good fibre-matrix interfacial adhesion which less fibre pull out, void and and small interface gap. Thus, the chemical treatment on KFM improved fibre-matrix adhesion, which also contributed to the enhancement of mechanical properties and physical properties compared to untreated KFM reinforced PP biocomposites.

Influence of alkaline treatment and fiber loading on the physical and mechanical properties of kenaf/polypropylene composites for variety of applications

Environmentally friendly biocomposites were made using plant-based natural fibers, such as henequen and kenaf. The natural fiber reinforced polypropylene (PP) and unsaturated polyester (UP) biocomposites were examined in terms of the reinforcing effect of natural fibers on thermoplastic and thermosetting polymers. Kenaf (KE) and henequen (HQ) fibers were treated with an electron beam (EB) of 10 and 200 kGy doses, respectively, or with a 5 wt% NaOH solution. Four types of biocomposites (KE/PP, HQ/PP, KE/UP and HQ/UP) were fabricated by compression molding and each biocomposite was characterized by dynamic mechanical analysis and thermogravimetric analysis. The kenaf fiber had the larger reinforcing effect on the dynamic mechanical properties of both PP and UP biocomposites than the henequen fiber. The highest storage modulus was obtained from the biocomposite with the combination of UP matrix and 200 kGy EB treated kenaf fibers.

Roselle fiber is a type of natural fiber that can potentially be used as a reinforcement material in polymer composites for different applications. This study investigated the chemical, physical, thermal, mechanical, and morphological characteristics of roselle fiber‐reinforced vinyl ester subjected to different fiber treatments. The roselle fiber was treated with alkalization and a silane coupling agent, and samples were prepared using the hand lay‐up method. Treated roselle fiber significantly enhanced most of the properties of vinyl ester biocomposites compared with an untreated biocomposite. The results revealed that alkalization and silane treatment of the fiber changed its chemical properties. The treated fiber improved water repellence behavior of the roselle fiber‐reinforced vinyl ester compared with the untreated fiber. Use of a silane coupling agent was determined as the best chemical treatment for the water absorption effect. Thermogravimetric analysis (TGA) demonstrated that alkalization‐treated fiber had improved thermal stability; however, the opposite result was obtained with the silane‐treated fiber. The morphological examination of treated and untreated roselle fiber‐reinforced vinyl esters showed a good fiber adhesion between the treated fiber and the matrix, and less fiber pull‐out from the matrix was observed. This observation provides good indication of the interfacial interlocking between the fiber and the matrix, which improved the tensile properties of the composites. In contrast, the impact results revealed that the treated fiber had a decreased impact energy compared with the untreated fiber. POLYM. COMPOS., 39:274–287, 2018. © 2016 Society of Plastics Engineers

This study investigated the rheological and mechanical properties of cement composites with kenaf and jute fibers for use in shotcrete. The length and volume fractions of the fiber were varied; the rheological properties were analyzed in terms of air content, compression and flexural tests were conducted, and the degree of fiber dispersion was assessed using fluorescence microscopy. The rougher surfaces of the jute fibers led to a higher yield stress and viscosity of the composite compared to the kenaf fibers. The use of 10-mm-long jute fibers at 2.0% volume fraction led to optimal rheological properties while 30-mm-long jute fibers at 1.0% resulted in the worst properties. The yield stress and plastic viscosity exhibited positive and negative correlations with the fiber volume fraction, respectively. This was likely because of the bridging and fluid actions of the bubbles at higher fiber content. For a given fiber content, only the yield stress increases with an increase in fiber length. Although all the mechanical properties deteriorated (compressive strength decreased from 27.5 to 6 MPa, and flexural strength deteriorated from 6.2 to 1.8 MPa), the mixtures failed in a ductile manner. Using 10-mm-long kenaf fibers at 2.0% induced optimal fiber dispersion, whereas the minimum dispersion-coefficient value was found for 5-mm-long kenaf fibers at 0.5%.

9 - Stress relaxation behavior of polymer-based composites

The application of principal components analysis for the comparison of chemical and physical properties among activated carbon models