Green Composite Material Research Articles

In situ loading of ZnO on hierarchical porous carbon derived from banana-peel waste to enrich mechanism for microwave absorption

Biomass has received widespread attention due to its easy availability, low cost, and environmental friendliness as an electromagnetic wave absorber candidate. Inspired by the natural porosity of biomass, the three-dimensional (3D) porous carbon materials derived from banana peels were prepared via coordination and pyrolysis carbonization. A conductive network of biomass-zinc complexes was constructed by introducing Zn2+ to coordinate with organic polymers. Hierarchical porous carbon/ZnO composites with a 3D skeleton network were obtained, which demonstrated outstanding electromagnetic wave absorption performance with an effective absorption bandwidth (EAB) of 6.72 GHz and the reflection loss (RL) of −44.18 dB. The banana peel-derived porous carbon (BPC) embedded with ZnO particles brings about conductive loss and interface polarization, further enriching the microwave loss mechanisms. This work offers a fresh idea for creating a green, sustainable, and high-value functional carbon-based composite material.

Improved carbon fibers dispersion in geopolymer composites

Carbon fibers (CFs) reinforced alkali-activated (AA) ground granulated blast furnace slag (GGBFS) geopolymer composites have excellent mechanical and thermoelectrical properties, as well as low energy consumption and low CO2 emissions during their production. However, the dispersion of CFs in the geopolymer matrix is always a technical issue in the preparation of the green composite material. Therefore, this study comparatively investigated various dispersion methods, including, mixing sequence (pre-mixing and after-mixing methods), dispersing agent (nano silicon dioxide [nSiO2]), and ultrasonic treatment time (0, 15, 30, and 45 min), as well as CFs content (0.5, 1.0, and 1.5 wt% of GGBFS). The distribution of CFs was then qualitatively and quantitatively evaluated by a series of tests, such as flowability, electrical resistivity, flexural strength, scanning electron microscope (SEM) analysis, and X-ray computed tomography (CT). The experimental results showed that the proposed pre-mixing method provided excellent dispersion characteristics for CFs compared with the after-mixing method. The introduction of nSiO2 can enhance the dispersion of CFs and the mechanical and electrical properties of AA GGBFS geopolymer composites. At a carbon fiber content of 1.5 %, the pre-mixing method and the addition of nSiO2 dispersant reduced the resistivity of the 28-day geopolymer composites by 17.0 % and 38 %, respectively, compared with the after-mixing method. It is feasible to use X-ray CT scanning with the gray-scale frequency map to analyze the dispersion effect of CFs in AA GGBFS geopolymer composites. However, the results were not intuitive when less agglomeration of CFs occurred for the low content of CFs. The scanning method is more applicable to the sample with over 1.0 wt% CFs. The average pixel areas of uniformly dispersed CF bundles in the 2D images of the pre-mixing method and the addition of nSiO2 dispersant specimens were 3.32 % and 6.55 % higher than those of the after-mixing method, respectively. The 2D and 3D scanning results from the dispersion characteristics of CFs were consistent. 2D scanning could provide a time-consuming option for the measurement of CFs dispersion characteristics.

Biomass-derived carbon heterostructure composites modified with magnetic iron oxide for excellent EMW-absorbing materials

With the gradual spread of satellite navigation, broadcasting, and communication technologies, the problem of electromagnetic pollution in C- and Ku-band has increased. Electromagnetic wave (EMW) absorbing materials can effectively mitigate this problem. Here, we report the design of a biomass carbon heterostructure for the absorption of EMWs. This design takes advantage of the natural fiber mesh structure of the loofah and the voids, veins, and basal tissues surrounding the fibers. The material is then carbonized to create a radar antenna-like structure of fibers and nanosheets. This improves the material's conductive loss. In addition, modification with magnetic iron oxide in loofah sponges improves the impedance matching of the materials, enhances the magnetic loss, and increases the heterogeneous interface. We found that the maximum effective absorption frequency range of the prepared EMW-absorbing materials is 3.80 GHz, which is mainly concentrated in the C-band and Ku-band, and its maximum RLminvalue is −59.20 dB. The material's ability to absorb EMWs was also verified by simulating the radar cross section (RCS). In conclusion, this work develops a green and efficient composite material for absorbing EMWs and provides new design ideas for the development of EMW-absorbing materials.

Investigation of phosphogypsum-based cementitious materials: The effect of lime modification

Phosphogypsum-based cementitious material (PBC) is acknowledged as a low-carbon green composite material. The addition of lime to modify PBC has been found to significantly enhance PBC utilization rate. This study investigates the effects of varying lime contents in PBC on mechanical properties, volume expansion, hydration products, micromorphology, and pore structure of modified Phosphogypsum (PS). The results demonstrate that lime effectively counteracts the retarding effect of water-soluble impurities in PS, thereby reducing setting time. Additionally, the 7 days and 28 days strength of PBC initially increases and then decreases with increasing lime content, with the 28 days compressive strength of B0 (0.5%) reaching 48 MPa. A 0.5% lime-modified PS proves beneficial in promoting PBC hydration, reducing pore size, densifying the microstructure, and enhancing mechanical properties. Moreover, the volume expansion results highlight the significant influence of the alkaline environment on both the generation and distribution of ettringite, consequently impacting PBC expansion.

Tensile properties and dynamic mechanical analysis of kenaf/epoxy composites

Kenaf fibre-reinforced polymer composites could offer low-cost, biodegradable, recyclable, and renewable materials. The hydrophilic kenaf fibres exhibit poor compatibility with the hydrophobic epoxy matrix as compared to their synthetic counterparts and ultimately, this may severely constrain their potential as a green composite material. This work aims to evaluate the tensile properties and dynamic mechanical analysis (DMA) of kenaf fibre composites reinforced with two epoxy systems as matrices, B and M resins. Neat epoxy samples and kenaf-reinforced composites with varying fibre loading, 15% and 45% were fabricated in the study. It was found that the tensile properties of kenaf composites are dependent on the epoxy resin systems and higher with reinforcement content. The tensile strength of M-15% and M-45% are 16.3% and 12.0% stronger than their counterparts. Determination of interfacial shear strength using a modified micromechanical model was employed showing that M-45 has a higher value than B-45%, 107.09 kPa and 90.28 kPa respectively. By DMA, in general, an increase in the storage modulus and peak height in the loss modulus was always higher with kenaf composites that were manufactured with the M resin system. The adhesion factor, A calculated from tan delta curves and cole-cole plot has shown the state of fibre/matrix adhesion level in each epoxy resin system. The SEM analysis indicates the presence of void spaces around fibres and matrix may attributed to the lower compatibility of the B resins system used in kenaf composites fabrication.

Exploring the potential of Tamarindus indica stem short macro fibers reinforced guar gum resin green composites

In this study, Tamarindus indica stem fibers and guar gum resin matrix have been used for the production of green composites with varying fiber lengths of 4, 8, and 12 mm and fiber loading of 5%, 10%, and 15 wt%, by hand lay-up process. The green composites were subjected to Fourier transform-infrared spectroscopy, thermal, mechanical, fractography, and water absorption tests as per American Standard Testing of Materials standards. The composites displayed a significant absorption peak at 3303 cm−1, signifying the existence of a hydroxyl group, as indicated by Fourier transform-infrared spectroscopy. The thermogravimetric analysis results showed that the composites were thermally stable up to 225 °C and displayed an endothermic peak at 103 °C. Untreated 4 mm fiber length and 15% fiber loading in the matrix material resulted in superior tensile and flexural characteristics, with values of 23.87 and 33.21 MPa, respectively, compared to other green composites. The composite with a 12 mm fiber length and 5% fiber load exhibited the highest impact resistance, with a load of 75 kJ/mm2, and demonstrated better resistance to water absorption. Furthermore, an eco-friendly flowerpot was developed using the mechanically optimized US0415 green composite material under real-world conditions.

Mechanical and Tribological Characterization of Green Composite Fabricated by Wheat Flour and Wheat Straw

The excessive use of traditional plastic polymers has elevated environmental concerns. These polymers are extremely difficult to dispose off. It takes a long time for plastics to disintegrate. These plastics enter into river water through several channels, and for a considerable amount of time, it flow with the stream. Numerous marine creatures get sick after ingesting the trash and animals on the ground. Therefore, an effort is made for such a green composite which do not harm the creatures and animals. A green composite material was fabricated by compression molding using wheat flour (WF) as a matrix and wheat straw (WS) as a reinforcement. Both materials are natural and digestible for living beings. WS was lighter than WF, so the addition of WS made the composite lighter. A poly-lactic acid (PLA) coating was done over the surface of the WF-WS composite to make it water resistant and wear resistant. The pin on disc wear test was performed to get the specific wear rate of the composite. The air jet erosion was also carried out to know the erosion value of the composite. The thermo-gravimetric analysis was performed to investigate the thermal stability of the composite in order to ensure the use of the composite up to 200° C. It was found that the addition of WS fibers in the composite increased thermal stability. The scratch test was conducted to find out the strength of the 1 mm thickness coating. The WF-WS composite with PLA coating can be used in non-load bearing components and light weight applications. It can also be used for eco-friendly food packaging materials.

Green composite colorimetric and “Turn-on” fluorescent material for the detection of Al3+ ion in blood serum and herbal tea

In the present investigation, we fabricated an ecologically sustainable green composite material derived from green raw materials, including cellulose nanomaterials and Morin. This innovative material underscores its commitment to environmental friendliness and boasts distinctive surface properties that render it an ideal substrate. The selection of this material was motivated by its intricate network structure and inherent capacity for surface modifications. The crux of our methodology involved the integration of the organic probe 2-(2,4-dihydroxyphenyl)-3,5,7-trihydroxychromen-4-one, commonly known as Morin, onto the surface of the cellulose nanocomposite. This strategic embedding of Morin conferred the composite material with exceptional attributes, enabling preconcentration, spectrophotometric determination, and fluorometric turn-on sensing of Al3+ ions. This unique property facilitated the ion-sensing of Al3+ ions in diverse samples, including blood serum and herbal tea.The resultant Morin green composite material exhibited remarkable sensitivity toward Al3+ ions in aqueous solutions, accomplishing extraordinary LOD as low as 0.26 ppb. This heightened sensitivity permits for precise and efficient ion-sensing and enables the detection to be perceptible to the naked eye. Notably, the Morin green composite material displayed a rapid and distinct color change within a brief span of less than two minutes when exposed to varying concentrations of Al3+ ions. Beyond its analytical prowess, the developed Morin green composite material demonstrated significant efficacy in practical applications. Specifically, it showcased remarkable performance in detecting Al3+ ions in serum samples and herbal tea samples.

Effect of spent alumina catalyst and date palm fiber ash addition in the development of aluminum based composite

This study focuses on utilizing waste aluminum as a base material and aims to fabricate a new green composite material by incorporating industrial aluminum waste, carbonized date palm fiber (CDPF), and spent alumina catalyst (SAC) powder as reinforcing agents. Initially, this type of waste disposal SAC, along with date palm fiber ash, has not been used before. In practical applications, we can utilize our composite in the automobile industry since the results show improved mechanical properties and reduced corrosion. By introducing 1.25% SAC and 6.25% carbonized palm fiber (CDPF) particles into the waste aluminum, significant improvements have been observed in mechanical characteristics like tensile strength, hardness, and toughness. Comparative analysis with the base material reveals enhancements of approximately 20.82%, 33.11%, and 22.72% in tensile strength, hardness, and toughness, respectively. Moreover, a reduction in composite elasticity has been observed. The SEM and EDX results demonstrate a uniform microstructure in the composite material. Corrosion experiments indicate that the addition of SAC and CDPF effectively minimizes the annual corrosion rate.

Comparing non-biodegradable plastic with environmentally friendly natural fibre composite on car front bumpers design

Production of plastic is growing, and plastics are used in a variety of products. However, plastics are not biodegradable and do not decompose easily. To overcome the problems in decomposition of plastics, the use of a specific type of natural fibre composite (NFC) material for front-bumper in cars is considered in this investigation. NFCs have the advantages of being environmentally friendly, light weight and high strength. The use of jute fibre is adopted for the design of a car front bumper and compared with the plastic bumper through Finite Element Analysis. The aim is to identify their performances in terms of impact energy, strength and resilience. The results show that when both materials were simulated under the same impact force, jute fibre has a lower equivalent stress with 177.1 MPa compare with 293.18 MPa on plastic material. This finding indicates that jute fibre has greater yield limit and more resilient to fracture. The simulation result also shows that jute fibre has a higher equivalent stress of 65.55 MPa on the front bumper compare with a lower equivalent stress of 39.94 MPa on plastic. This suggests that plastic material will yield soon when an impact force is higher. The total deformation after the same impact force in jute fibre is 2.1 mm, which is significantly less than the deformation in plastic with 11.7 mm. Therefore, this research concludes that jute fibre can potentially replace plastic as a green composite material application to minimise environmental damages.Graphical abstract

Tensile Property of Jute Fiber Sliver Reinforced Green Composite Material under Loading Speed

To assess the safety and utility of green composite materials as a sustainable structural material, this study investigated their tensile properties using unidirectional jute fiber sliver and poly (lactic acid) and poly (butylene succinate) under loading speed. The fiber volume fraction of the green composite materials was about 10%. Vacuum compression molding was used for molding. Static tensile tests of green composite materials using poly (lactic acid) and poly (butylene succinate) were conducted with 0.1–10 mm/min test speed at room temperature, yielding the following conclusions. Tensile strengths of green composite materials using poly (lactic acid) and poly (butylene succinate) increased with increased test speed. The strain rate dependence of the green composite using poly (lactic acid) became strong, but the strain rate dependence of green composite material using poly (butylene succinate) became weak. Results suggest that the matrix viscoelasticity might influence the loading speed effects on the tensile properties of these green composite materials.

Remediation of ibuprofen and naproxen in water by a green composite material of magnetic carbon nanotube–metal–organic framework

This work adopted a simple and green method for synthesizing a composite of magnetic carboxylic multi–walled carbon nanotube–metal–organic frame (MCNTs–UiO–66–NH2) at room temperature, which was applied to the remediation of ibuprofen (Ibu) and naproxen (Nap) in wastewater. The influencing factors of adsorption were investigated, including adsorbent dosage, pH value, coexisting ions, temperature, and contact time, etc. Various methods were employed for analyzing the structural features and surface characteristics exhibited by MCNTs–UiO–66–NH2. The values of max adsorption quantity about MCNTs–UiO–66–NH2 toward Ibu and Nap reached 143 mg·g–1 and 139 mg·g–1 at 313 K, respectively. The Langmuir model and Pseudo–second–order model can describe the adsorption process of Ibu and Nap. According to the values of the thermodynamic parameters, both adsorption processes were endothermic, spontaneous and could lead to an increase in entropy. In addition, the composite can be used to capture Ibu and Nap in the pH range of 1–10 and the salinity range of 0–0.2 mol·L–1 with an ideal regeneration performance taking 5 mmol·L–1 NaHCO3 as eluent. The mechanism of adsorption is including complexation, π–π conjugation, electrostatic action and H–bonding. These properties confirm MCNTs–UiO–66–NH2 as one potential adsorbent for remediation of Ibu and Nap in wastewater.

Investigation of mechanical and viscoelastic properties of Agave cantala fiber-reinforced green composites for structural applications

This study explored using cellulosic plant fibers as composite-reinforcing materials for structural applications. Specifically, a green composite material was created using Agave cantala fiber (ACF) and an epoxy matrix with weight fractions ranging from 30% to 60%. The laminates were fabricated using a compression molding technique, which involved alternating layers of resin and fibers on a flat mold. The fibers were uniformly aligned, and the resin was layered over them. The mold was then covered with polyethylene film to ensure that voids were minimized, and the mold was compressed for 12 h at ambient temperature. Four different samples were created by varying the fiber and resin weight percentages, with ACF30 containing 30% fiber and 70% resin, ACF40 containing 40% fiber and 60% resin, ACF50 containing 50% fiber and 50% resin, and ACF60 containing 60% fiber and 40% resin. The resulting composites were characterized to investigate their mechanical properties and it was found that the 40% ACF laminates had the maximum tensile, flexural, and compressive moduli and strengths. Additionally, viscoelastic characteristics were evaluated, and the 40% ACF composite demonstrated the highest storage and loss moduli. Scanning electron microscopy was also used to interpret the interface between the fibers and the matrix at the fracture surfaces. These findings suggest that cellulosic plant fibers have the potential as reinforcement materials for creating high-performance composites.

Thermal and mechanical evaluation of natural fibers reinforced gypsum plaster composite

Many problems such as the increase in the world population, global drought, and greenhouse gases have caused materials used in industries to be reconsidered. This is how the concept of green composite material emerged. Using natural fibers to obtain such materials is important in terms of sustainability. This study is aimed to use hemp fiber and banana fiber as natural fiber additives in the gypsum composite to produce green bio-composite. Natural fibers are chemically modified with 5% NaOH solution. In this way, a good fiber/matrix interface interaction is provided. The composite hardness test result of 5 wt% HB fiber added sample is obtained as 50.4. Compared to the control plaster sample test result, which is 53.6, a slight decrease can be seen. However, it is observed that the fibers held the structure together and sopped the crack propagation. The increase in the porous structure with fiber addition caused a decrease in the thermal conductivity of the composite. Comparing thermal conductivity result of 5 wt% HB fiber reinforced gypsum composite (0.131 W⸳mK-1) with respect to pure gypsum result (0.237 W⸳mK-1), it gave a promising result as an insulation material.

Potential of New Sustainable Green Geopolymer Metal Composite (GGMC) Material as Mould Insert for Rapid Tooling (RT) in Injection Moulding Process.

The investigation of mould inserts in the injection moulding process using metal epoxy composite (MEC) with pure metal filler particles is gaining popularity among researchers. Therefore, to attain zero emissions, the idea of recycling metal waste from industries and workshops must be investigated (waste free) because metal recycling conserves natural resources while requiring less energy to manufacture new products than virgin raw materials would. The utilisation of metal scrap for rapid tooling (RT) in the injection moulding industry is a fascinating and potentially viable approach. On the other hand, epoxy that can endure high temperatures (>220 °C) is challenging to find and expensive. Meanwhile, industrial scrap from coal-fired power plants can be a precursor to creating geopolymer materials with desired physical and mechanical qualities for RT applications. One intriguing attribute of geopolymer is its ability to endure temperatures up to 1000 °C. Nonetheless, geopolymer has a higher compressive strength of 60-80 MPa (8700-11,600 psi) than epoxy (68.95 MPa) (10,000 psi). Aside from its low cost, geopolymer offers superior resilience to harsh environments and high compressive and flexural strength. This research aims to investigate the possibility of generating a new sustainable material by integrating several types of metals in green geopolymer metal composite (GGMC) mould inserts for RT in the injection moulding process. It is necessary to examine and investigate the optimal formulation of GGMC as mould inserts for RT in the injection moulding process. With less expensive and more ecologically friendly components, the GGMC is expected to be a superior choice as a mould insert for RT. This research substantially impacts environmental preservation, cost reduction, and maintaining and sustaining the metal waste management system. As a result of the lower cost of recycled metals, sectors such as mould-making and machining will profit the most.

Adsorption of Carvone and Limonene from Caraway essential oil onto Tunisian montmorillonite clay for pharmaceutical application

To explore a novel kind of green composite material having excellent antibacterial, antifungal ability and specific-targeting capability for pharmaceutical uses, a novel kind of bio-composite was prepared using sodium purified clay as carrier of Caraway essential oil (CEO). Gas chromatography-mass spectroscopy (GC–MS) analyses of CEO reveals that Carvone (68.30%) and Limonene (22.54%) are the two major components with a minimum inhibitory concentration (MIC) value equal to 125 mg/mL against Staphylococcus (S) aureus bacteria and Candida albicans fungi. Clay from Zaghouan was purified and characterized by X-ray Photoelectron Spectroscopy (XPS), X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR) and N2 adsorption–desorption (BET method). Results obtained by chromatograph equipped with a flame ionization detector (GC-FID) show that the concentration of 130 mg/mL of essential oil and 5 h of contact with the purified clay are the optimal conditions for the bio-hybrid formation. The pseudo-second-order model can describe the kinetic study of the adsorption of Carvone and Limonene on sodium montmorillonite, and the adsorption isotherms have been established to the Langmuir type. Limonene registers a maximum adsorption value equal to 3.05 mg/g of clay however Carvone register the higher amount of adsorption (19.98 mg/g) according to its polarity and the abundance of this compound in the crude CEO. X-ray diffraction, Fourier transformed infrared spectroscopy, elemental analyses (CHN) and X-ray fluorescence characterization valid the success adsorption of CEO in sodium montmorillonite surface. The purified clay/CEO hybrid (purified clay/CEO) combined the advantages of both the clay and the essential oil used in exerting the antibacterial and antifungal activity, and thus, the composite has a double antibacterial and antifungal activity compared to the separately uses of inactive clay and CEO, suggesting the great potential application in pharmaceutical treatments.

Material innovation and performance optimization of multi-solid waste-based composite grouting materials for semi-flexible pavements

With the increasing power generation capacity of circulating fluidized bed boilers and electrolytic aluminum production worldwide, the emissions of fluidized bed coal combustion fly ash (FBCF) and bayer red mud (BRM) have increased dramatically, resulting in extremely severe environmental issues as it is difficult to utilize these as resources. To address this issue, this study uses industrial solid wastes such as BRM, FBCF, and silica fume as mineral admixtures to develop a green and low-carbon early strength multi-solid waste composite grouting material (ESMSWCGM) for semi-flexible pavements (SFPs). According to the findings of this study, 18 % of the cement in the ESMSWCGM could be replaced with the three solid waste mineral admixtures. With the optimal ratio, the developed ESMSWCGM exhibits initial and 20-min flow-cone fluidities of 12 s and 14 s, respectively, and initial and final setting times of 66 min and 69 min, respectively. The compressive strengths at 3 h, 1 d, 7 d, and 28 d are 17.05 MPa, 22.95 MPa, 29.55 MPa, and 30.72 MPa, respectively, and the dry shrinkage rate at 28 d is 0.12 %. The performance of the SFP material obtained through grouting is excellent. When the grouting saturation is 95 %, the SFP has a dynamic stability of 28911, a rutting depth of 1.19 mm, and a splitting strength of 1.91 MPa.

Procedure for Spaced Mesh Modeling from Digital Images: Example of the Leaf Sheath of the Coconut Palm Cocos Nucifera L. (2D).

The characterization of the two-dimensional (2D) leaf sheath of the coconut palm Cocos nucifera from digital images is part of a research project that focuses on the feasibility of using a local natural resource, the leaf sheath of the coconut palm C. nucifera (2D), for the development of a green composite material and the analysis of the influence of this type of reinforcement, which has the advantage of being naturally woven, on the properties of the biocomposites obtained. In order to characterize these properties, it is essential to extract information from the leaf sheath samples. This work consists of counting and evaluating the thicknesses and directions of all the fibers that make up the sheath. In simple cases, from sample photographs, we wish to propose a processing chain capable of automating this extraction process. We are interested here only in samples with areas of spacing between the fibers. Therefore, our proposal cannot be a solution for tightly packed fibers. The data are represented by photographs of leaf sheath samples taken with a high-resolution microscope. This results in color images of 3000 × 3000 pixels. In the following, we will call EI a space in which it is possible to locate a pixel by its spatial coordinates, and we will call EC another space in which it is possible to locate the color of a pixel by its colorimetric coordinates. In EI, the set representing the pixels denoting the fiber will be denoted EF and that representing the void areas will be denoted EV. From these starting sets, the work consisted of finding a process that allows the extraction and characterization of points of interest representing the leaf sheath.

Experimental Study on the Mechanics and Impact Resistance of Multiphase Lightweight Aggregate Concrete

Multiphase lightweight aggregate concrete (MLAC) is a green composite building material prepared by replacing part of the crushed stone in concrete with other coarse aggregates to save construction ore resources. For the best MLAC performance in this paper, four kinds of coarse aggregate—coal gangue ceramsite, fly ash ceramsite, pumice and coral—were used in different dosages (10%, 20%, 30% and 40%) of the total coarse aggregate replacement. Mechanical property and impact resistance tests on each MLAC group showed that, when coal gangue ceramsite was 20%, the mechanical properties and impact resistance of concrete were the best. The compressive, flexural and splitting tensile strength and impact energy dissipation increased by 29.25, 19.93, 13.89 and 8.2%, respectively, compared with benchmark concrete. The impact loss evolution equation established by the two-parameter Weibull distribution model effectively describes the damage evolution process of MLAC under dynamic loading. The results of a comprehensive performance evaluation of four multiphase light aggregate concretes are coal gangue ceramsite concrete (CGC) > fly ash ceramsite concrete (FAC) > coral aggregate concrete (CC) > pumice aggregate concrete (PC).

Comprehensive characterization of raw and treated pineapple leaf fiber/polylactic acid green composites manufactured by 3D printing technique

AbstractThe aim of this study is to develop a completely sustainable, biodegradable, eco‐friendly and green composite material for packaging of food and medical products by an additive manufacturing technique such as 3D printing. This report presents the mechanical, crystalline, chemical bonding and thermal characteristics of a novel pineapple leaf fiber (PALF) reinforcing polylactic acid (PLA) green composite manufactured by 3D printing technique. Both powdered raw and alkali‐treated PALFs were respectively mixed with PLA and extruded as filaments for 3D printing into composite test specimens. The characterization study reveals that the 3D printed composite with 3 wt% (alkali‐treated) PALF reinforcement exhibited maximum tensile and flexural characteristics. The density of the 3D printed composite specimens increased with increase in wt% of PALF. On the other hand, the 3D printed composite specimens blended with raw PALF showed enhanced elongation at break compared to alkali‐treated PALF reinforced composite specimens. The microstructural images of the 3D printed composite specimens confirms the existence of impurities, voids and fiber degradation phenomenon. The Fourier transform infrared spectra revealed the chemical bonding nature of the 3D printed composite specimens. The X‐Ray diffraction was used to calculate the crystalline size and crystallinity index. Thermogravimetric analysis reveals that the 3D printed composite specimen possessed adequate thermal stability for use in packaging applications.