Biocomposites For Applications Research Articles

Chemical Composition and Thermal Behavior of Kraft Lignins

Lignin has great potential for utilization as a green raw material or as an additive in various industrial applications, such as energy, valuable chemicals, or cost-effective materials. In this study, we assessed a commercial form of lignin isolated using LignoBoost technology (LB lignin) as well as three other types of lignin (two samples of non-wood lignins and one hardwood kraft lignin) isolated from the waste liquors produced during the pulping process. Measurements were taken for elemental analysis, methoxyl and ash content, higher heating values, thermogravimetric analysis, and molecular weight determination. We found that the elemental composition of the isolated lignins affected their thermal stability, activation energies, and higher heating values. The lignin samples examined showed varying amounts of functional groups, inorganic component compositions, and molecular weight distributions. Mean activation energies ranged from 93 to 281 kJ/mol. Lignins with bimodal molecular weight distribution were thermally decomposed in two stages, whereas the LB lignin showing a unimodal molecular weight distribution was decomposed in a single thermal stage. Based on its thermal properties, the LB lignin may find direct applications in biocomposites where a higher thermal resistance is required.

Effect of Superheated Steam Treatment on the Mechanical Properties and Dimensional Stability of PALF/PLA Biocomposite.

The effectiveness of superheated steam (SHS) as an alternative, eco-friendly treatment method to modify the surface of pineapple leaf fiber (PALF) for biocomposite applications was investigated. The aim of this treatment was to improve the interfacial adhesion between the fiber and the polymer. The treatment was carried out in an SHS oven for different temperatures (190–230 °C) and times (30–120 min). Biocomposites fabricated from SHS-treated PALFs and polylactic acid (PLA) at a weight ratio of 30:70 were prepared via melt-blending techniques. The mechanical properties, dimensional stability, scanning electron microscopy (SEM), and X-ray diffraction (XRD) for the biocomposites were evaluated. Results showed that treatment at temperature of 220 °C for 60 min gave the optimum tensile properties compared to other treatment temperatures. The tensile, flexural, and impact properties as well as the dimensional stability of the biocomposites were enhanced by the presence of SHS-treated PALF. The SEM analysis showed improvement in the interfacial adhesion between PLA and SHS-treated PALF. XRD analysis showed an increase in the crystallinity with the addition of SHS-PALF. The results suggest that SHS can be used as an environmentally friendly treatment method for the modification of PALF in biocomposite production.

Fabrication, characterization, and application of biocomposites from poly(lactic acid) with renewable rice husk as reinforcement

Filaments for three-dimensional printing were fabricated from composites based from biodegradable Poly(lactic Acid) (PLA) and renewable rice husk (RH). Acrylic acid (AA)-grafted PLA (PLA-g-AA) and coupling agent-treated rice husk (TRH) were incorporated to improve the properties of PLA/RH biocomposites. The biocomposite morphology, tensile properties, water absorption, and biodegradability were investigated. PLA-g-AA/TRH demonstrated superior tensile properties than PLA/RH because of the improved compatibility between the polymer and the TRH. TRH was evenly dispersed in the PLA-g-AA, brought about by ester reaction; consequently, branched and three-dimensional networks structures were generated. These PLA-g-AA/TRH biocomposites can be used as biodegradable materials or filaments for 3D printing applications because of their low cost and excellent properties.

Improving the stability of bacteriocin extracted from Enterococcus faecium by immobilization onto cellulose nanocrystals

Enterococcus faecium (E. faecium) isolated from Vigna mungo (Black gram) produced bacteriocin that inhibits both Gram positive and Gram negative bacteria and better heat stability (100 °C for 30 min). The bacteriocin was sensitive to protease treatment and most active in acidic pH. Bacteriocin produced by Pediococcus acidilactici was used for comparison. To enhance stability for diversified applications, the bacteriocin was immobilized by physical adsorption onto cellulose nanocrystals (CNC) extracted from cotton linters. The bacteriocin immobilization yield was 64.91% for P. acidilactici and 53.63% for E. faecium. The bacteriocin immobilized CNC was characterized by DLS particle sizing, FTIR and AFM to evaluate size distribution, chemical nature and surface morphology. The bacteriocins immobilized on CNC showed 50% increase in stability in terms of antibacterial activity. The enzymatic synthesis of CNC in combination with physical adsorption immobilization method for bacteriocin makes it an efficient system of producing antibacterial nanofillers for food packaging and bio-composites applications.

Finding the Additives Incorporation Moment in Hybrid Natural Pigments Synthesis to Improve Bioresin Properties

Interest in applications of natural dye applications has increased because of their antibacterial properties and the possibility of extracting them from nature and residues. Using nanoclays as hosts to reinforce natural dye properties has been successfully demonstrated. However, no one has attempted to optimize the polymer matrix and hybrid pigment properties at the same time to ensure the best final properties for bio-composite applications. Using a statistical design for experiments, we propose the best combination of modifiers with the best nanoclay as the host of three natural dyes: chlorophyll, β-carotene, and betanine. Using the L9 Taguchi designs, we learned both the influence of the nanoclay structure, and the addition moment of surfactant, mordant salt, and silane modifiers. FTIR, XRD, DTG, integration sphere spectrophotometer, and UV-aging tests were used to characterize the hybrid pigments and epoxy bioresin composites. The degradation temperatures of the three natural dyes rose and the reinforcement of the stability of three natural dyes to UV–Vis radiation exposure was demonstrated, which avoided the migration of these dyes from bioresin to wet ribbing. Optimal results were obtained with hydrotalcite clay (calcined or not) by using surfactant and mordant before the natural dye, and before or after silane.

Preparation and antibacterial properties of nano biocomposite Poly(ε-caprolactone)-SiO2 films with nanosilver

Two different silica samples with different particle size distributions (Silica-I: 40–63 μm, Silica-II: 90% below <55 μm) were utilized after the nano silver (5–30 nm) coating process by poly(dimethylsiloxane) in acetone. The prepared nano Ag-silica powders were melt-mixed into poly(e-caprolactone) (PCL) and the mixture was roll-milled to produce the nano biocomposite films containing 10%, 20% and 40% nano Ag-silica. The antibacterial activity of the composite films against E. coli was evaluated. For the PCL films with 40% Ag-silica (0.08–0.12% nanosilver), 100% reduction of the bacterial contamination was observed. The nanosilver coated silica particles could find applications in antibacterial nano biocomposites.

Development and evaluation of water absorption, compression and impact properties of okra Nanofibrillated cellulose reinforcement in epoxy resin composites

Abstract Nanofibrillated cellulose were extracted from natural fibre of Okra plant by a chemical, Acid hydrolysis and mechanical method to study their potential for use as reinforcement fibrils in bio composite applications. The okra Nanofibrillated cellulose composites were prepared by Compression moulding and VARTM method. The Present work was to investigate water absorption, compression and impact properties of okra Nanofibrillated cellulose reinforced epoxy composites. The water absorption compression and impact of okra Nanofibers Reinforced Epoxy composites were studied and the effects of okra Nanofiber (0, 1, 2, 4 and 6 wt%) are also examined. The water absorption, compression and impact properties of Nanofibre reinforcement has improved when compared with the virgin composite. Water Absorption capacity is less for okra Nanofibrillated cellulose reinforced epoxy resin composites sample when compared to other composite samples but it is high when compared to pure epoxy resin sample. The compression strength of 4 wt% okra Nanofibrillated cellulose composites shows improve quality result among other composites and it gives 4 wt% improved strength of the pure epoxy resin composites. Whereas 4 wt% okra Nanofibrillated cellulose composites (OKCNFs) shows improve impact strength as compared to Epoxy resin composites. The okra Nanofibrillated cellulose composites are tested by means water absorption, compression and impact test based on ASTM standard. Effect of Fibril surface Treatment on water absorption, compression and impact properties are also observed.

SUSTAINABLE BIO-COMPOSITE ITS MANUFACTURING PROCESSES AND APPLICATIONS

The biocomposite materials which serve for present nation or civilization without affecting our future generation is called as sustainable biocomposite i.e., it does not affect our environment and save our environment from toxic and hazardous effect. The sources and production of the raw materials, material Processing, the service-life of the product and waste management should be evaluated in terms of energy, chemical consumption, emissions of gaseous materials, toxicology upon use and disposal of a biocomposite are considered as sustainable bio-composites. This can be formed by different manufacturing process like filament winding, lay up method, extrusion moulding, Injection moulding, compression moulding, Resin transfer moulding, Sheet moulding compound etc. Sustainable biocomposite have several advantages like light weight, high specific stiffness, high strength, low electrical conductivity, easily bondable, good fatigue resistance, internal energy storage and release, low thermal expansion, easily moulded to complex and design flexibility etc. These biocomposite have huge applications in several fields like in the field of domestic sector, building materials, aerospace industry, circuit boards and automobile applications. It supports our sustainable environment by using natural fibres like jute, hemp, sisal, knead, flax etc. which is the cause of biodegradation and can also be used in the industrial scale. It not only saves our environment but also made our life easier and more comfortable.

Plasmonic Hybrid Biocomposite as an Effective Substrate for Detection of Biomolecules by Surface-Enhanced Raman Spectroscopy

The enhancement of the Raman light scattering signal from the surface of the porous hybrid biocomposites based on polyhydroxybutyrate (PHB), calcium carbonate (CaCO3), and nanoplasmonic Ag particles is investigated. Based on PHB, fibrous scaffolds are obtained by the electrospinning technique. The fibrous scaffolds have been covered by CaCO3 and Ag nanoparticles by means of mineralization in salt solutions and Ag reduction reaction. Successful formation of the CaCO3 and Ag nanoparticles on the scaffold surface has been confirmed by the data of scanning electron microscopy, x-ray diffraction analysis, and infrared spectroscopy. Surface-enhanced Raman spectroscopy (SERS) of the obtained sample surface has demonstrated a significant enhancement of the Rhodamine 6G signal (Ef > 105) in comparison with the reference sample where the analyte concentration and the laser power were 100 times higher. Thus, the present research has confirmed prospects for the application of biocomposites based on polyhydroxybutyrate for detection and investigation of biomolecules by the SERS method.

Bio-composite materials: a short review of recent trends, mechanical and chemical properties, and applications

Recently, the attraction on the bio-composite (known as green composites) materials has significantly increased due to the potential of being substitute to conventional materials used in manufacturing industries. Bio-composite materials are produced with natural fibres or natural resins instead of synthesized fibres (carbon, glass, etc fibres) or resins (poly vinyl alcohol, epoxy, etc resins ). The bio-based fibres such as jute, sisal, flax, hemp, bamboo, hair, wool, silk etc., are obtained from plants or animals. Also, natural matrix materials such as natural rubber, polyester, etc., are produced from plants. The advantages of bio-composites such as the ease of disposal and being able to composted characteristics of bio-composites after the expiration date which is not generally possible with conventional synthetic materials, being renewable, sustainable have attracted many researcher. Furthermore, the comparable mechanical properties of bio-composites make feasible for application to many different products. This study reviews the, recent trends, mechanical and chemical properties, and application of bio-composites in recent years.

Isolation and characterization of cellulose nanocrystals from Saharan aloe vera cactus fibers

Saharan aloe vera cactus leaves fibers (SACLFs) are a biodegradable and renewable agro textile fiber enriched with cellulose polysaccharides. The isolation of cellulose nanocrystals (CNCs) from SACLFs is an alternative approach to reinforcement for bio-composites applications. In this study, we show that standard chemical methods for the extraction of cellulose microfibrils and sulfuric acid hydrolysis (64 wt%) will result in usable CNCs. The resulting CNCs were characterized by XRD, FTIR, TGA and TEM. Fourier Transform Infrared Spectroscopy (FT-IR) confirms that the maximum amount of noncellulosic materials is removed from SACLFs. High yield content (32%) of CNCs is achieved by sulfuric acid hydrolysis and sonication process. It also enhances the crystalline size and crystallinity index of CNCs, which are confirmed by XRD. TEM analysis of CNCs shows a rod-like structure with diameter (10–14 nm), length (200–255 nm) and high aspect ratio of 18–20, which confers good reinforcing properties. These were tested in biodegradable agar film, whose tensile strength is increased by 27% when 5 wt% of CNCs from SACLFs was incorporated into the matrix. The SACLFs represent an interesting source of cellulosic reinforcing materials.

Sustainable Carbonaceous Biofiller from Miscanthus: Size Reduction, Characterization, and Potential Bio-composites Applications

The use of biocarbon derived from renewable resources to substitute for petroleum-based carbonaceous materials in composites and other applications often requires size reduction. Biocarbon obtained by the pyrolysis of miscanthus was subjected to ball milling from 2 to 24 h. Particle analysis was performed by combining scanning electron microscope imaging and image-based particle counting. The milled biocarbon had a highly heterogeneous shape and size distribution, making image-based analysis the most suitable method. The average particle size was reduced from above 3 µm after 2 h of milling to below 1 µm after 24 h of milling. The specific surface area doubled from 148 m²/g to approximately 300 m²/g after 2 h of milling, but it did not change with longer milling. Ball milling caused a gradual decrease of the thermal conductivity from 0.137 to 0.116 W·m-1·K-1. The ash content increased from 8 to 17% after 24 h of milling. Polypropylene composites filled with the biocarbon with and without ball milling showed lower density and comparable mechanical properties to a talc-filled composite except for lower impact strength. Using ball milled biocarbon led to a steady increase of the impact strength with longer milling time, reaching values on a par with that of the talc composite.

Converting spent battery anode waste into a porous biocomposite with high Pb(II) ion capture capacity from solution

Abstract Taking advantage of the low-cost carbon and manganese sources of the spent battery anode waste (SB), porous biocomposites were synthesized by co-pyrolyzing of SB with sawdust. Synthesis method was optimized, and potential biocomposite application in the aspect of Pb(II) removal in the wastewater was investigated and the related possible mechanism of Pb(II) removal was discussed. Composite derived at 750 °C with 10% SB loading amount had high Pb(II) adsorption capacity with negligible influence of ion strength. The maximum Pb(II) adsorption capacity was around 183.82 mg/g at 298 K and pH 4, and the increase of the temperature favored Pb(II) adsorption. Pb(II) adsorption behavior fitted the intraparticle diffusion model and Redlich-Pearson model. Pb(II) removal was governed by precipitation, complexation and Cπ−Pb(II) bond interaction combined processes. Co-pyrolysis of sawdust with SB not only explores an approach for the SB utilization but also provides an excellent biocomposite for solution Pb(II) ion adsorptive removal.

Toxicity assessment of chlorpyrifos-degrading fungal bio-composites and their environmental risks

Bioremediation techniques coupling with functional microorganisms have emerged as the most promising approaches for in-situ elimination of pesticide residue. However, the environmental safety of bio-products based on microorganisms or engineered enzymes was rarely known. Here, we described the toxicity assessment of two previously fabricated fungal bio-composites which were used for the biodegradation of chlorpyrifos, to clarify their potential risks on the environment and non-target organisms. Firstly, the acute and chronic toxicity of prepared bio-composites were evaluated using mice and rabbits, indicating neither acute nor chronic effect was induced via short-term or continuous exposure. Then, the acute mortality on zebrafish was investigated, which implied the application of fungal bio-composites had no lethal risk on aquatic organisms. Meanwhile, the assessment on soil organic matters suggested that no threat was posed to soil quality. Finally, by monitoring, the germination of cabbage was not affected by the exposure to two bio-products. Therefore, the application of fungal bio-composites for chlorpyrifos elimination cannot induce toxic risk to the environment and non-target organisms, which insured the safety of these engineered bio-products for realistic management of pesticide residue, and provided new insights for further development of bioremediation techniques based on functional microorganisms.

Lightning strike evaluation on composite and biocomposite vertical-axis wind turbine blade using structural health monitoring approach

Lightning damages to wind turbine blades increase as the size of wind turbine becomes larger. The damages are quite serious since it contributes to high cost of repairs and loss of electric power production. Since natural plant fibres receive attention nowadays due to low density and high specific strength, the usage of natural fibre to replace synthetic fibre in fabricating the turbine blade will promote a green renewable material. As the application of biocomposite for wind turbine blade has been explored, the effect of lightning strike damage has been required for further test investigation. This article explores the comparative results of performing lightning strike damage testing on composite (fibreglass) and biocomposite (flax fibre) wind turbine blades with protective metal mesh materials. The damage assessments were performed using visual non-destructive inspection methods and piezoelectric sensor as part of structural health monitoring. From the result, it is found that fibreglass blade experienced larger damage area compared to flax fibre blade based on the visual test conducted.

An approach to use agricultural waste fibre in polymer (polypropylene: PP) for bio–composites applications

The mechanical properties of rice husk composites were studied The range of added rice husk is and of polypropylene weight and the rise husk ratio was Natural fiber extracted from plants has gained attentions owing to their advantages over synthetic polymers Nowadays composites from natural fibers are among the most keenly required materials In the present study raw rice husk was treated in order to enhance the properties The purpose of using annealing method is to increase the rate of reaction Change in morphology of rice husk was found when treated through SEM technique The goal of the present study is to show that chemical treatment is an effective method to enhance the properties of rice husk that may be used as reinforcement in polymers to make ecofriendly lightweight biodegradable polymer composites The properties polypropylene PP rice husk RH composites were analyzed as a function of the RH amount All prepared composites showed improved fibers dispersion in the polypropylene matrix All composites displayed lower elongation of break compared to pure PP Recently interest in composite manufacturing has shifted towards the use of natural fibres as reinforcement because of their environmental benefits The use of a biodegradable matrix is worth considering since this would result in a completely biodegradable composite In order to assess the most suitable matrix polymer one must know the properties of the available polymers Since data tend to be widely scattered over many sources and are very scarce compared to the conventional polymers it is the purpose of this article to give an overview of the most relevant properties of a range of biodegradable polymers An overview such as the one given here may provide a useful guide in establishing the best compromise between conflicting property demands This research work describes the characterization and fabrication of bio ndash composites In recent years the incorporation of natural fibers as reinforcing agent in polymers has gained increasing interest which enhances optimal utilization of natural resources and particularly of renewable resources Natural fibers have proven to be suitable reinforcement materials for composite thanks to a combination of good mechanical and thermal properties with environmental advantages such as renewability and bio ndash degradability comparable to synthetic fiber reinforced polymer composites Hence for these reasons it has not been surprising that the use of natural materials in the production of composites has gained significant importance both in technical applications such as in automotive industry The effect of rice husk concentration in composite has been analyzed In order to improve the strength and to reduce the sensitivity to environmental influences the interfacial adhesion between the natural fiber and the matrix material was improved by chemical treatment of the rice husk

Biocomposite application for the phosphate ions removal in aqueous medium

Mango stone biocomposite efficiency for the removal of phosphate ions (PO43−) from aqueous solution was investigated as a function of pH (2–8), biocomposite dose (0.05–0.40g/100mL solution), contact time (5–120min), initial PO43− ions concentration (20–800mg/L) and temperature (33–61°C). Maximum PO43− ions removal was achieved at pH 2, biocomposite dose 0.3g, contact time 90min and initial PO43− ions concentration 200mg/L. At optimized conditions, up to 95mg/g PO43− adsorption was achieved. Biocomposite pre-treatment with surfactants (SDS, Tween-80, C-TAB, VIM and Surf excel) were also investigated and it was observed that surfactants pre-treatments decreased the adsorption capacity of the biocomposite. Thermodynamic study (ΔG0, ΔH0 and ΔS0) revealed that PO43− adsorption process onto biocomposite was spontaneous and endothermic in nature. Adsorption data fitted well to the Freundlich isotherm and pseudo-second-order kinetic model. Adsorbed PO43− was successfully desorbed using 1.0M NaOH solution. Results revealed that biocomposite adsorbed PO43−, which could possibly be used for the adsorption of PO43− efficiently from wastewater.

Effect of Moringa oleifera Pod Husk Fibers on the Properties of Gelatin-Based Biocomposite

The objective of this work is to study the feasibility of reinforcing polymer composites by utilizing the biofibers from the agricultural residue of Moringa oleifera pod husks (MOPH). The chemical and physical properties of the fibers were comprehensively investigated to evaluate their potential as a filler in gelatin-based films. The effect of MOPH fiber concentrations of 0, 5, 10, and 15 wt% on the water vapor permeability (WVP), and mechanical and thermal properties of the gelatin-based films was studied. By incorporation of 10 wt% of the MOPH fibers in gelatin, the highest tensile strength and Young’s modulus, and the lowest WVP properties were obtained. Scanning electron microscopy (SEM) photographs indicated good interfacial adhesion between the fibers and the gelatin matrix. TGA of the biocomposites revealed an improvement of thermal stability. Moreover, under accelerated weathering, the gelatin-MOPH-10% biocomposite degraded more slowly than the gelatin control. These results indicate that the MOPH fibers are a good reinforcing filler and may be useful for biocomposite applications.

Thermal behavior of extruded and injection‐molded poly(lactic acid)–talc engineered biocomposites: Effects of material design, thermal history, and shear stresses during melt processing

ABSTRACTReinforced biocomposites were compounded by the reactive extrusion of poly(lactic acid) (PLA) and chemically modified microlamellar talcs. Talc was functionalized by the hydrolysis and condensation reaction of its surface hydroxyl groups with different kinds of organosilanes, namely, 3‐aminopropyl triethoxysilane and (3‐glycidoxypropyl)trimethoxysilane, and commercially available tri‐isocyanates, namely, Bayhydur 3100 and Desmodur 3900, which feature hydrophilic and hydrophobic behaviors, respectively. PLA–talc biocomposites were also compounded by the addition of two types of reactive biodegradable compatibilizing agents, namely, maleic anhydride and glycidyl methacrylate modified PLA. The resulting compounds were melt‐processed by injection molding to get flat substrates with different formulations. The thermal responses of the extruded compounds and injection‐molded items, specifically the first and second thermal transitions, were analyzed by differential scanning calorimetry. In particular, the influence of the different material formulations, their thermal history, and/or shear stress in single‐ or multiple‐stage heating and/or melt processing on the glass transition, crystallinity, and melting behavior of the biocomposites was investigated. The experimental findings revealed that the macroscopic thermal response of the compounds (i.e., extruded pellets) and substrates (i.e., injection‐molded flat slabs) manufactured by the melt processing of the available formulations was controlled and significantly improved by the fine‐tuning of the chemical (i.e., reaction mechanisms, chemical bonds) and physical interactions (i.e., steric hindrances, physical bonds) among the modified talc, PLA, and compatibilizing agents. These results are of great practical importance and open up broader scenarios for the industrial application of biopolymers and biocomposites, specifically in all of those consumer goods where thermal stability and the preservation of mechanical performance at moderate and high temperatures of the materials are pivotal. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45179.

Glycidyl methacrylate-compatibilized poly(lactic acid)/hemp hurd biocomposites: Processing, crystallization, and thermo-mechanical response

Poly(lactic acid)-based biocomposites were developed with hemp hurd (Cannabis sativa L.) with grafting-based interfacial compatibilization. Poly(lactic acid) was extruded with hemp hurd and glycidyl methacrylate as the polymer/hurd interfacial compatibilizer, and injection molded. Interfacial compatibility between poly(lactic acid) and hemp hurd increased with grafted glycidyl methacrylate in comparison to the non-compatibilized control, as corroborated by scanning electron microscopy fractography and mechanical analysis, which showed increases in the glycidyl methacrylate-grafted 20% (w/w) hemp hurd/poly(lactic acid) biocomposite, retaining 94% of the neat polymer strength, with increases in crystallinity, and showing a range of thermo-mechanical properties desirable for rigid biocomposite applications.