Characterization and Comparison of Rheological Properties of Agro Fiber Filled High-Density Polyethylene Bio-Composites

The rheological behavior of composites made with high-density polyethylene (HDPE) and different agro fiber by-products such as corncob (CCF), Rice hull (RHF), Flax shives (FSF) and Walnut shell (WSF) flour of 60 - 100 mesh were studied. The experimental results were obtained from samples containing 65 vol.% agro fiber and 3 wt.% lubricant. Particle sizes distribution of the agro fibers was in the range of 0.295 mm to ?0.125 mm. SEM showed evidence of complete matrix/fiber impregnation or wetting. The melt rheological data in terms of complex viscosity (η*), storage modulus (G'), loss modulus (G"), and loss tangent (tanδ) were evaluated and compared for different samples. Due to higher probability of agglomeration formation in the samples containing 65 vol.% of agro fillers, the storage modulus, loss modulus and complex viscosity of these samples were high. The unique change in all the samples is due to the particle size distribution of the agro fibers. The storage and loss modulus increased with increasing shear rates for all the composites, except for Walnut shell composite which exhibited unusual decrease in storage modulus with increasing shear rate. Damping factor (tanδ) decreased with increasing shear rate for all the composites at 65 vol.% filler load although there were differences among the composites. Maximum torque tended to increase at the 65 vol.% agro fiber load for all composites. Corncob and Walnut shell composites gave higher torque and steady state torque values in comparison with Flax shives and Rice hull composites due to differences in particle sizes distribution of the agro fibers.

New Type Bio-composites Containing Nitrogenous Fertilizers of Prolonged Action and Nitrogen-Fixing Microorganisms

Technology was developed for obtaining ecologically pure composites containing nitrogenous fertilizers of prolonged action and nitrogen-fixing microorganisms in order to increase productivity of cereal crops. As a result of application of this composite nitrogenous fertilizer hectare norm decreases by 40%-55%, while productivity increases by 15%-30%, compared to those of the control.

Development and characterization of mycelium bio-composites by utilization of different agricultural residual byproducts

Mycelium bio-composites was developed by incubating Pleurotus ostreatus fungi on different sub-strates from agricultural residual byproducts,including rice straw,bagasse,coir-pith,sawdust,and corn straw.The scanning electron microscope(SEM)results showed that the hypha of com-posite derived from bagasse was the densest,and the diameter of hypha was the biggest(0.77μm),which was presumably due to the existence of cellulose in bagasse in the form of dextran and xylan.The maximum and minimum compression strength for sawdust substrate and corn straw substrate were 456.70 and 270.31 kPa,respectively.The flexural strength for bagasse sub-strate and rice straw substrate were 0.54 and 0.16 MPa,respectively.The two composites derived from rice straw and bagasse exhibited higher hydrophobic properties than others.In comparison,mycelium bio-composite derived from bagasse showed the best comprehensive properties.Except for a little worse anti-creep ability and waterproof performance,other properties of mycelium bio-composites could be comparable to commercially expanded polystyrene(EPS)packaging mate-rial.Derived from this study,mycelium material provided a good way to use agricultural residual byproducts and could be a good alternative to non-biodegradable materials for packaging appli-cations.

New Ulva lactuca Algae Based Chitosan Bio-composites for Bioremediation of Cd(II)Ions

The current article covers the production of chitosan(CS)from shells of shrimp waste and its utilization in the preparation of eco-friendly imprinting and non-imprinting composites with Ulva lactuca algae(Alg).These bio-composites namely(Imp-Alg-25wt%CS)and(NImp-Alg-25wt%CS)were used for removal of Cd(II)ions.Fourier transform infrared(FT-IR)spectra,scanning electron microscope(SEM)equipped with electron dispersive X-ray(EDX),X-ray diffraction(XRD),and elemental analysis measurements were performed to characterize these bio-composites sorbents.The highest adsorption of these sorbents towards Cd(II)ions was determined as a function of solutions pH,contact time,Cd(II)ion concentration,beads dose,and temperature.The equilibrium experimental data were treated using various mathematical isotherm and kinetic models to approve the maximum bio-sorption capacities of NImp-Alg-25wt%CS and Imp-Alg-25wt%CS(in mg/g).The results exhibited that Imp-Alg-25wt%CS gave higher removal capacity than NImp-Alg-25wt%CS at the same optimum parameters.Pseudo-2nd order dynamic and Langmuir isotherm models were well described in these biosorption processes.Thermodynamically,the removal behavior of Cd(II)using both bio-composites was spontaneous at room temperature.The reusability of the sorbents,NImp-Alg-25wt%CS and Imp-Alg-25wt%CS,showed three cycles.In addition,comparative study was also conducted for Cd(II)removal onto some reported sorbents.

Evaluation of Novel Chitosan Based Composites Coating on Wettability for Pure Titanium Implants

This work aims to prepare chitosan(CS)-based coated layers,CS(10 wt%nanosilver/90 wt%CS,10 wt%biotin/90 wt%CS,and 5 wt%nanosilver–5 wt%biotin)/90 wt%CS coatings are prepared,onto pure Ti substrate.The surface morphology of the novel CS composite coating was studied using field emission scanning electron microscopy,atomic force microscopy(AFM),Fourier transforms infrared(FTIR)and wettability test.Results show that the addition of(biotin,nanosilver)5 Vol.%improves the properties of composite materials.Using different particles’scale size aid in improving the combinations in the alginate,producing a dual effect on film properties.Coating surface roughness decreased in the chitosan-based biocomposite with preferable homogeneity and crack-free coating layers,as confirmed by AFM.An increase in surface roughness ensured substitution,which enhanced the surface structures.The high wettability of the CS-based coating layers was due to the presence of nanoparticles,and the composite coatings with CS,nanosilver,or biotin had excellent wettability because of the good hydrophilic nature of the CS matrix combined with reinforced particles.The FTIR results showed that peaks of the blending of CS plus nanoparticles,CS plus biotin,or CS plus nanosilver plus biotin were excellent matching with no changes in the structure of the matrix.

Optimization of Extrusion Process Parameters of Recycled High-Density Polyethylene-Thermoplastic Starch Composite for Fused Filament Fabrication

High-density poly-ethylene (HDPE) is a nonbiodegradable recyclable plastic which is widely utilized in single use packaging applications. Consequently, it constitutes a significant amount of plastic waste found in landfills. From literature, it has been shown that parts produced using composites of HDPE with carbohydrate-based polymers, such as thermoplastic starch (TPS), experience mechanical degradation through hydrolytic degradation process. The possible utilization of recycled-HDPE (rHDPE) and TPS composite in nonconventional manufacturing processes such as Fused filament fabrication (FFF) has however not been explored. This study explores the potential application of rHDPE and TPS composites in FFF and optimizes the extrusion process parameters used in rHDPE-TPS filament production process. Taguchi method was utilized to analyze the extrusion process. The extrusion process parameters studied were the spooling speed, extrusion speed and the extrusion temperatures. The response variable studied was the filament diameter. In this research, the maximum TPS content achieved during filament production was 40 wt%. This filament was however challenging to use in FFF printers due to frequent nozzle clogging. Printing was therefore done with filaments that contained 0 - 30 wt% TPS. The experimental results showed that the most significant parameter in extrusion process was the spooling speed, followed by extrusion speed. Extrusion temperature had the least significant influence on the filament diameter. It was observed that increase in TPS content resulted in reduced warping and increased rate of hydrolytic degradation. Mechanical properties of printed parts were investigated and the results showed that increasing TPS content resulted in reduction in tensile strength, reduction in compression strength and increase in stiffness. The findings of this research provide valuable insights to plastic recycling industries and researchers regarding the utilization of recycled HDPE and TPS composites as substitute materials in FFF.

Characterization of Ceramic Filled Polymer Matrix Composite Used for Biomedical Applications

A particulate composite material was prepared by adding (CaCO3, CaO, MgCO3, MgO) ceramic particles with particle size of (2 (0.5% wt.). The results had revealed that the maximum values of tensile strength, compression, bending strength, hardness, impact energy and water absorption%, were (57.6828 N/mm2 at 3% wt. CaCO3, 124.0965 N/mm2 at 9% wt. CaCO3, 102.188 N/mm2 at 9% wt. MgO, 88.2 Shore D at 9% wt. CaCO3, 0.27 J at 6%wt. CaCO3 and 0.8432 % at 15%wt.CaO) compared with reference values, i.e.( 37.4742 N/mm2, 100.3563 N/mm2, 34.194 N/mm2, 83 Shore D, 0.36 J and 0.2626%) respectively.

Fiber-Reinforced Polymer Bridge Design in the Netherlands： Architectural Challenges toward Innovative, Sustainable, and Durable Bridges

This paper reviews the use of fiber-reinforced polymers （FRPs） in architectural and structural bridge design in the Netherlands. The challenges and opportunities of this relatively new material, both for the architect and the engineer, are discussed. An inventory of recent structural solutions in FRP is included, followed by a discussion on architectural FRP applications derived from the architectural practice of the author and of other pioneers.

Recent Trends in Preparation and Applications of Biodegradable Polymer Composites

This review efficiently covers the research progress in the area of polymer bio composites in perspective of the modern-day renewable materials.In the last decade,attraction towards the bio-composite based systems has been the topic of interest due to their potential as a substitute of conventional materials produced in important manufacturing industries.Recently,preparation of biocompatible and biodegradable polymer composites is an important achievement as an alternative of petrochemical based renewable products.Successful production of eco-friendly bio-composite materials have been achieved with natural fibers viz jute,bamboo,hair,flex,wool,silk and many others instead of synthesized fibers like carbon,glass dispersed in synthesized resins viz poly vinyl alcohol,epoxy and etc.Biomaterials based on natural fibers dispersed in natural matrix like natural rubber or polyester have also been obtained with endless applications for the mankind.The utilization of such materials for the good well of mankind is attributed to their ease of disposal and being renewable.The last but not the least,the extraordinary mechanical properties of bio-composites make them superior to many other conventional materials.This review paper addresses the recent trends,mechanical and chemical properties,synthesis,and application of bio-composites in the recent years.

Effect of Recycling Cycles on the Mechanical and Damping Properties of Flax Fibre Reinforced Elium Composite:Experimental and Numerical Studies

This manuscript deals with the effects of recycling on the static and dynamic properties of flax fibers reinforced thermoplastic composites.The corresponding thermoplastic used in this work is Elium resin.It’s the first liquid thermoplastic resin that allows the production of recycled composite parts with promising mechanical behavior.It appeared on the resin market in 2014.But until now,no studies were available concerning how it can be recycled and reused.For this study,a thermocompression recycling process was investigated and applied to Elium resin.Flax fiber-reinforced Elium composites were produced using a resin infusion process and were subjected to different thermomechanical recycling operations.For each material,five recycling operations were carried out on the raw material.A total of 10 different materials were investigated and tested by means of tensile and free vibration tests to evaluate the effect of recycling on their behavior.In addition,a finite element model of the dynamic problem was developed to evaluate the loss factor and natural frequencies regarding different cases.The results obtained show that the failure tensile properties of Elium resin as well as flax fiber reinforced composites decrease during recycling operations.Conversely,recycling induces a rise in the elastic modulus.Moreover,improvement in the dynamic stiffness was observed with recycling operations.But repeated recycling appeared to have negligible effects on the loss factor of the recycled materials.The results obtained from the experiment and the numerical analyses were in close agreement.

Research Achievements and Trends in Forest Products Science in Indonesia

The supply of logs for wood industries during the period 2004-2008 was 13.5-32 million cubic meters per year. Logs from plantation forest reached about 65%, which was exploited from industrial plantation forest, Perum Perhutani, as a government enterprise, community forest and estate. The changing log supply from natural forest to plantation forest implies changing of wood species, cutting cycle, log diameter and wood properties. Research concerning the utilization of fast growing species, small log diameter, lesser used species and other llignocellulosic material have been intensively done by some research institutes and universities, and were related to wood properties, wood properties enhancement, wood chemistry, bio-composite, wood engineering, and also non-timber forest products.

The Thermal and Crystallization Studies of Luffa Fiber Reinforced Poly Lactic Acid Composites

Poly lactic acid (PLA)—chemically treated fiber of Luffa cylindrica (LC) composites were fabricated by micro-compounding followed by injection molding method. Before reinforcement, LC fibers were exposed to chemical treatment like alkali treatment, bleaching and acid hydrolysis. The chemically treated LC fibers were then modified with Ca salts to explore their uses in bio medical industries. Thermal stability of chemically extracted cellulose fibers of LC and PLA composites reinforced with 2 wt%, 5 wt% and 10 wt% LC fibers were studied by thermo gravimetric analysis (TGA) in the temperature range from 30℃ to 700℃. Better interfacial bonding between fiber and matrix was evidenced by increased thermal stability of composites due to incorporation of fiber. Crystallization and melting behavior of PLA composites were studied in the temperature range from 30℃ to 170℃ at heating rate of 10°/minute. The crystallization temperature and crystallization enthalpy increased up to 2 wt% of LC fiber content and gradually decreased with further increase of fiber content in the composites. Double melting peaks were observed for all composite samples and possible explanations were suggested on the basis of different crystalline structure of PLA and melt crystallization phenomena.

Effect of trace HA on microstructure, mechanical properties and corrosion behavior of Mg-2Zn-0.5Sr alloy

Effect of the addition of trace HA particles into Mg-2Zn-0.5Sr on microstructure, mechanical properties, and bio-corrosion behavior was investigated in comparison with pure Mg. Microstructures of the Mg-2Zn-0.5Sr-xHA composites （x= 0, 0.1 and 0.3 wt%） were characterized by optical microscopy （OM）, scanning electron microscopy （SEM） equipped with energy dispersion spectroscopy （EDS） and X-ray diffraction （XRD）. Results of tensile tests at room temperature show that yield strength （YS） of Mg- 2Zn-0.5Sr/HA composites increases significantly, but the ultimate tensile strength （UTS） and elongation decrease with the addition of HA particles from 0 up to 0.3 wt%. Bio-corrosion behavior was investigated by immersion tests and electrochemical tests. Electrochemical tests show that corrosion potential （Ecorr） of Mg-2Zn-0.5Sr/HA composites significantly shifts toward nobler direction from -1724 to -1660 mVscE and the corrosion current density decreases from 479.8 to 280.8 p.Acm^-2 with the addition of HA particles. Immersion tests show that average corrosion rate of Mg-2Zn-0.BSr/HA composites decreases from 11.7 to 9.1 mm/year with the addition of HA particles from 0 wt% up to 0.3 wt%. Both microstructure and mechanical properties can be attributed to grain refinement and mechanical bonding of HA particles with second phases and α-Mg matrix. Bio-corrosion behavior can be attributed to grain refinement and the formation of a stable and dense CaHPO4 protective film due to the adsorption of Ca^2＋ on HA particles. Our analysis shows that the Mg-2Zn-0.5Sr/0.3HA with good strength and corrosion resistance can be a good material candidate for biomedical applications.