Eco-composite Materials Research Articles

Development of phase change eco-composite materials from eggshell waste

ABSTRACT The consumption of eggshell powder (ES) as an affluent source of calcium carbonate (CaCO3) can efficiently solve both ecological and financial interest. The use of eggshell waste in eco-composite materials (ECPCMs) is an attempt to reduce waste's negative effects. Eco-composite powders of polyethylene glycol (PEG) and calcium carbonate (CaCO3) were obtained by mechanical grinding. Compression molding was used to produce plates from the ground powders. FTIR spectroscopy and X-ray diffraction analysis showed that the ECPCMs were physically combined and the crystallinity of the two components was affected. According to TGA, the thermal stability of ECPCMs was improved, thanks to the use of eggshell waste powder. On the other hand, the results of the DSC showed that ECPCM with the addition of 90 wt% of PEG in the mixture provides excellent thermal stability and high energy storage density. In light of its high latent heat storage capacity of 156.1 J/g as well as its ability to prevent PEG exudation. Significant enhancement in melting-solidification time shows an improvement in Thermal Energy Storage (TES) response time by adding ES to the PCM. The obtained results indicate a good potential for industrially applied ECPCMs.

Characterizing eco-composite boards with non-woven polypropylene from disposable face masks and bamboo reinforcement

This study investigates the development of eco-composite panels using treated and untreated nonwoven polypropylene (PP) extracted from disposable medical face masks, reinforced with bamboo particles. Treated PP underwent a washing process with detergent. Panels were fabricated with varying PP-to-bamboo particle ratios of 100:0, 75:25, and 50:50. Fourier-transform infrared (FT-IR) spectroscopy analysis indicated minimal impact of washing on the intrinsic properties of the PP material, as confirmed by thermogravimetric analysis (TGA). Both analyses showed similar intensities of functional groups and thermal trends in treated and untreated recycled PP (rPP) samples. Energy-dispersive X-ray spectroscopy (EDX) confirmed the uniform integration of bamboo particles within the PP matrix by detecting silicon and potassium elements. Chemical interactions between bamboo fibres and the PP matrix were also evident in the form of reduced peak intensities in FT-IR spectra. Despite these interactions, limited adhesion between bamboo fibres and the PP matrix led to reduced stability and mechanical strength in the eco-composite panels. A direct correlation was observed between board thickness and the proportion of bamboo particles, with the 50:50 formulation showing the greatest thickness. Conversely, board strength decreased as bamboo particle concentration increased due to weak interfacial adhesion. Notably, panels made from treated rPP exhibited superior mechanical properties compared to those from untreated rPP, achieving a modulus of rupture (MOR) of 36.259 MPa and a modulus of elasticity (MOE) of 2048.215 MPa. These findings underscore the potential of utilizing nonwoven PP from disposable medical face masks, reinforced with bamboo fibre particles, to create eco-composite materials with enhanced sustainability and mechanical properties.

Effects of Wet and Dry Treatments on Surface Functional Groups and Mechanical Properties of Flax Fiber Composites

Flax fibers have found widespread use in eco-composite materials because of their remarkable mechanical properties compared to glass fibers. However, their low stability limits their use on a larger scale when employed in hot or humid environments. Therefore, the surfaces should be modified before the composite process to provide the best interfacial interactions and increase the dispersion of natural fibers. To tackle this problem, two kinds of modifications can be considered: wet and dry modifications. This research explores different methods to improve the adhesion between flax fibers and the poly lactic acid (PLA) polymer. Morphological and chemical modifications in the presence of acetone, alkali (as a wet modification), and with air atmospheric pressure plasma (as a dry modification) are compared in this research. The results revealed that altering the chemical characteristics on the surface significantly changed the mechanical properties of the final composite. More specifically, the Fourier transform infrared spectroscopy (FTIR) data indicate that wax-related peaks (2850 and 2920 cm−1) were eliminated by both wet and dry treatments. Dynamic mechanical analysis (DMA) results also highlighted that a better bond between the flax fibers and the PLA matrix is obtained with the plasma modification.

Experimental study of composite materials based on ecological wastes

Thermal insulation is a good strategy for saving energy and reducing the emission of CO2 especially when produced locally with ecological materials. The hereby document aims at evaluating the thermal and mechanical properties of eco-composite materials based on plaster and wood waste or granular cork. The proportion of used additives were respectively 20 and 30%. Two wood waste types were used as sawdust and wood chips; several granular sizes were used for granular cork. The thermal characterization consists of determining the thermal conductivity, and thermal effusivity of all samples. Flexural and compressive strength were also tested. Results show that the composite materials with 20% wood shaving, 20% granular cork size 3.35–6.7 mm, and 30% sawdust have improved thermal performance with acceptable mechanical resistances. The thermal simulation proves that using these composite materials as plasterboards in buildings can generate thermal energy gain about 38%, compared to reference building. These results indicate that the use of ecological composites based on plaster has a promising future in thermal building insulation.

Effective microorganisms composite scupper drain (EM-CSD) as a new revolution in drainage system: A preliminary study

Effective microorganisms composite scupper drain (EM-CSD) system, which is designed using eco-composite in porous concrete with the concrete mixture and a cement replacement, consists of the waste material elements that being recycled, such as wood waste ash, egg shells, rice husk ash (RHA), and many more, for the purpose of managing stormwater quantity and quality, and also for ecologically sustainable development. The numerous ecocomposite materials researches have been conducted, specifically for the building materials. In addition, several impermeable surfaces including sidewalks, secondary roads, and also parking lots in several countries have used the porous concrete materials, as it is good quality in terms of the concrete strength, the porosity, the workability, and also the maintenance cost reduction. Besides, previous researches related to effective microorganisms (EM) as an admixture in concrete have been done, as a part of construction materials. However, the previous researches of eco-composite, specifically using RHA and EM did not focus on the drainage systems. Therefore, this paper presents a preliminary study of EM-CSD system using RHA and EM as a cement replacement, as a green technology and sustainable development in urban drainage systems. This kind of technology is a new revolution to replace the existing drainage systems, with high cost effective consideration, high concrete mixture strength and workability, and low temperature. For the part of the research, Shah Alam, Selangor as the main study area to implement this kind of the new drainage system technology for the purpose to reduce the flash flood phenomenon, to overcome the dengue fever issues due to stagnant water in the drainage system, and also vandalism of the drainage cover, which cause a safety issue for public. This preliminary study using EM-CSD as a new revolution in the drainage system indicates the ecocomposite porous concrete mixtures are expected able to overcome the drainage system problems with low cost maintenance and high on concrete strength and workability.

Chemical modification of hemp fibres by plasma treatment for eco-composites based on biodegradable polyester

In this paper, raw hemp fibres were used to reinforce a commercial biopolyester, namely poly(1,4-butylene adipate-co-terephthalate), to achieve eco-composite materials. To promote the adhesion between the polyester matrix and the fibrous reinforcement, chemical modification of fibres surface with coupling agents was accomplished. Usually, the grafting of coupling molecules is carried out involving high amount of solvents. Here, in a general approach of an environmental sustainability, uncut, combed and slightly stretched hemp fibres were treated with a green process based on a novel soft plasma jet device (developed by Nadir Srl). This technique activates the fibres surface and, at the same time, allows the deposition of reactive monomers as coupling agents. Three different monomers were investigated: methyl methacrylate (MMA), (3-aminopropyl)triethoxysilane (APTES) and (3-glycidyloxypropyl)trimethoxysilane. Unmodified and surface-modified fibres were characterized and compared in terms of thermal behaviour and morphological features. Long-fibre eco-composites were then prepared by different compression moulding procedures and characterized by thermal, morphological and dynamic mechanical analysis. Experimental evidences indicated that the cold plasma deposition/grafting treatment was successfully carried out; the composite with the best mechanical performance resulted that obtained by using APTES as coupling agent.

Green technology and sustainable urban drainage systems using eco-composite porous concrete: A preliminary study

Eco-composite in porous concrete is designed with the mix of concrete and a cement replacement, which have the element waste material that being recycled, for example, rice husk ash (RHA), egg shells, palm oil fly ash, wood waste ash, and many more, for the purpose of ecologically sustainable development, and also for managing stormwater quantity and quality. The various researches related to eco-composite materials have been done, mainly as the construction and building materials. Besides, the porous concrete itself is mainly being used as paving material for the construction of parking lots, sidewalks and secondary roads. Thus, the good quality of porous concrete in terms of the concrete strength, the workability, the porosity, and so on are required. Meanwhile, previous researches related to effective microorganisms (EM) as an admixture in concrete have been done. However, the previous researches of eco-composite, specifically using RHA and EM did not focus on the drainage systems. Therefore, this paper presents a preliminary study of the eco-composite using RHA and EM as a cement replacement, as a green technology and sustainable development in urban drainage systems. For the part of the research, this technology, which is drain covers (slab) as part of the drainage system has been implemented in several areas in Selangor, specifically in Shah Alam in order to mitigate the flash flood, stagnant water lead to the mosquitos fertilization issue, and vandalism of the drainage cover, which cause a safety issue for public. The early findings seem encouraging that indicates the eco-composite porous concrete can be successfully in construction.

EFFECTS OF THE PRESENCE OF CELLULOSE AND CURAUA FIBERS IN THE THERMAL AND MECHANICAL PROPERTIES OF ECO-COMPOSITES BASED ON CELLULOSE ACETATE

Eco-composite materials have gained the interest of academia and industry due to their environmentally friendly features. In this work, two groups of eco-composites of cellulose acetate matrix reinforced with cellulose and curaua fibers were prepared by extrusion and injection method. The first group of eco-composites, were prepared on laboratory scale, with curaua fibers, virgin and treated by two different methods; extraction with acetone and mercerized. A second group of materials was obtained on pilot scale, for which cellulose fibers and curaua fibers treated with acetone were used at different times of extraction. The acetone treatment was selected because in the first group, the materials with these fibers presented better mechanical properties, and mainly for their lower thermal conductivity (0.132 W m-1 K-1), compared to those from untreated fibers (0.178 W m-1 K-1) and treated with NaOH (0.255 W m-1 K-1). The eco-composites prepared on a pilot scale with curaua fibers previously treatment with acetone for 5 days presented a better balance of their thermal and mechanical properties, which could allow their use as thermal insulation with high mechanical performance (thermal conductivity = 0.097 W m-1 K-1 and modulus of elasticity = 2.2 GPa).

Effect of water ageing on nanoindentation response of single hemp yarn/epoxy composites

This paper aims to evaluate the influence of water ageing on nanoindentation response of the in situ components of hemp/epoxy composites. Specific samples have been tested, made of single hemp yarn composites with two different epoxy resins. Analysis of indentation points depending on their location in the yarn microstructure has been performed. Measurements showed the influence of neighbouring fibres on the reduced modulus in the confined resin. Water induces a decrease in nanoindentation properties, and maximum decrease in reduced modulus takes place in the interfacial zone, which shows the significant degradation of the fibre/matrix interface caused by water ageing. Evolutions in the indentation properties induced by water are similar for both partially bio-based and fully synthetic epoxy resin composites. All these results bring insights into the influence of water ageing of each constituent of hemp fibre reinforced composites and give interesting data for developing eco-composite materials.

A Novel Process for the Production of Unidirectional Hybrid Flax/Paper Reinforcement for Eco-composite Materials

In this paper a new process to manufacture unidirectional reinforcements for eco-composite materials, made of natural fibers, is presented. Starting with flax rovings of different sizes, an apparatus was developed to feed and align the rovings over the wet-end section of a paper machine. The short kraft paper fibers are therefore mixed with the long flax roving as the machine is running, and at the end of the process, a sheet of the hybrid dry reinforcement is obtained and cut to size for impregnation with various resins, using different processes. This novel manufacturing process allows for high volume production of reinforcement. It is very flexible, and many different combinations of long and short fibers can be exploited for the production of a vast variety of dry reinforcements. In this paper, composite samples are obtained out of these reinforcements, using the resin infusion (RI) molding process with a commercial epoxy resin. The results are compared with those of usual glass fiber reinforcement. An interesting aspect is that the large variability, typical for natural fibers, is largely reduced when the short kraft fibers are present in the composite. In terms of permeability to resin, reasonably comparable values can be obtained compared to that of glass fabrics, if a low surface density of reinforcement is chosen.

Tension–tension fatigue behaviour of woven hemp fibre reinforced epoxy composite: A multi-instrumented damage analysis

The purpose of this work is to characterise the tensile–tensile fatigue behaviour of a woven hemp fibre reinforced epoxy composite, adding up analysis of fatigue damage mechanisms by combining different techniques: optical microscopic and X-ray micro-tomography observations, temperature field measurement by infrared camera, and acoustic emission monitoring (AE). Two different stacking sequences: [0°/90°] and [±45°] are compared. A power law based model is used to fit S–N curves of experimental results. [±45°]7 layups show better fatigue strength than [0°/90°]7 ones, in relative terms. This is explained by the difference of their damage behaviour, in concordance with the local shear stresses developing in [±45°]7 laminates. Moreover, high resolution micro-tomography pictures allow one to clearly visualise the yarn/matrix interface damage in these materials. The obtained results give a complete description of fatigue damage mechanisms, and a damage scenario during fatigue tests is proposed for these eco-composite materials.

Polysaccharide Ecocomposite Materials: Synthesis, Characterization and Application for Removal of Pollutants and Bacteria

A novel, simple and totally recyclable method has been developed for the synthesis of nontoxic, biocompatible and biodegradable composite materials from cellulose and chitosan. In this method, [BMIm+Cl-], an ionic liquid (IL), was used as a solvent to dissolve and synthesize the [CEL+CS] composite materials. Since the IL can be removed from the materials by washing them with water, and recovered from the washed solution, the method is totally recyclable. XRD, FTIR, NIR and SEM were used to characterize the materials and to confirm that CEL and CS were successfully regenerated by the method without any chemical transformation. More importantly, we have successfully demonstrated that [CEL+CS] material can serve as an effective adsorbent for removal various endocrine disruptors including polychlorophenols and bisphenol A. This is because the composites have combined advantages of their components, namely superior chemical stability and mechanical stability (from CEL) and excellent adsorption capability for pollutants (from CS).

Polysaccharide Ecocomposite Materials: Synthesis, Characterization and Application in Removal of Pollutants and Bacteria

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Potential of using coconut shell particle fillers in eco-composite materials

Morphology and mechanical properties of coconut shell particles reinforced epoxy composites were evaluated to assess the possibility of using it as a new material in engineering applications. Coconut shell filled composites were prepared from epoxy polymer matrix containing up to 30 wt% coconut shell fillers. The effects of coconut shell particle content on the mechanical properties of the composites were investigated. Scanning electron microscopy (SEM) of the composite surfaces indicates that there are fairly good interfacial interaction between coconut shell particles and epoxy matrix. It was shown that the value of tensile modulus and tensile strength values increases with the increase of coconut shell particles content, while the impact strength slightly decreased, compared to pure epoxy resin. This work has shown that coconut shell particles can be used to improve properties of epoxy polymer composite to be used in eco-buildings.

Effects of fibre surface treatment on fracture-mechanical properties of sisal-fibre composites

Sisal fibre reinforced composites, one class of a broad range of eco-composite materials, were studied in connection with the effects of fibre surface treatment on their fracture-mechanical properties. Previous investigations on sisal fibre and its composites have been fully reviewed [1], which provided an impetus for this research. Two fibre surface treatment methods, chemical coupling based on silane and oxidization based on permanganate and dicumyl peroxide, together with untreated sisal fiber composites were used to set up different levels of interface bonding strength. The interface effects on the mechanical properties and fracture toughness of sisal fibre reinforced vinyl-ester composites were completely assessed based on the test results obtained and theoretical analyses. Many aspects of studies reported in this paper are original, such as single fiber pull-out tests and toughness evaluation of sisal composites aided by scanning electron microscopy. The results showed that fibre surface treatment could improve interfacial bonding properties between sisal fibre and vinylester resin. These in turn influenced the fracture-mechanical characteristics of this class of ecocomposites.

Prediction of the Dielectric Properties of Some Eco-composite Materials for Energy-related Applications

The study establishes a theoretical evaluation trough several models concerning the dielectric properties of some new eco-composites made of a cellulosic derivative matrix - hydroxypropyl methylcellulose (HPMC) - in which distinct sorts of fillers (ceramic, metallic and bio-derived) were introduced. The investigation describes the impact of the filler addition on the dielectric constant, the dielectric breakdown, and finally how these two factors are contributing to the electric energy density of purposed eco-composites. After incorporation of the reinforcement agents, the dielectric constant significantly increases comparatively with the matrix, as a function of the type of filler used. Moreover, by assessing of the dielectric breakdown, it is observed that with the increase of filler quantity, this parameter slightly decreases for all samples. The data concerning the electric energy density reveal that, by filler insertion in the HPMC matrix, an improvement occurs, especially for the barium titanate system owing to its large dielectric constant. These data are promising for design of new eco-composites having improved dielectric features as demanded for green energy storage devices. Since the materials have biodegradable and biocompatible character, they also have importance in bio-related applications.