Water Absorption Tests Research Articles

Eco‐friendly enhancement of poly(lactic acid)/poly(butylene adipate‐co‐terephthalate) bridgeable composites using natural cotton stalk: A novel approach to improved mechanical, barrier properties, and compatibility

AbstractThis study investigates the potential of using natural cotton stalk (CS) to enhance the properties of poly(lactic acid) (PLA) and poly(butylene adipate‐co‐terephthalate) (PBAT) composite materials. Simple processed CS, used as a bio‐based filler, is integrated into the PLA/PBAT matrix with the objective of improving mechanical properties, barrier performance, and compatibility, while simultaneously reducing costs and environmental impact. The experiments conducted include tensile testing, scanning electron microscopy analysis, Fourier‐transform infrared spectroscopy (FTIR) analysis, X‐ray diffraction study, thermogravimetric analysis, contact angle measurement, water absorption tests, as well as water vapor and oxygen permeability tests. The results demonstrate that the inclusion of CS significantly enhances the mechanical properties and crystallinity of PLA/PBAT composites, along with increasing their water vapor and oxygen barrier capabilities. Compared to PLA/PBAT without CS, the addition of 2% CS to PLA/PBAT led to substantial improvements in tensile strength and elongation at break, with increases of 21.5%, 41.6%, and 74.4%, respectively. Additionally, scanning electron microscopy and Fourier‐transform infrared spectroscopy analyses indicate that the incorporation of CS promotes the compatibility and chemical interaction between PLA and PBAT, thereby enhancing various properties of the composite material. Image analysis revealed that the distribution area of CS fibers in the polymer matrix increased with content up to a peak at 2% but decreased at higher contents due to severe agglomeration, leading to uneven distribution and performance decline. This work proposes three possible reasons for the improvement in water vapor and oxygen permeability performance. Overall, the analysis suggests that an optimal amount of CS can effectively enhance multiple properties of PLA/PBAT composites, while excessive CS may lead to a decline in performance.Highlights Cotton stalk (CS) boosts polylactic acid/poly(butylene adipate‐co‐terephthalate) (PLA/PBAT) tensile strength by 21.5% and elongation by 41.6% at 2% inclusion. CS addition enhances water vapor and oxygen barrier properties of PLA/PBAT. Scanning electron microscopy and Fourier‐transform infrared spectroscopy show CS improves PLA/PBAT compatibility and strength. Optimal CS content at 2% identified for best mechanical and barrier performance. Study validates using agricultural waste as fillers in eco‐friendly composites.

SUSTAINABLE CONCRETE PRODUCTION USING WASTE GLASS POWDER AS A PARTIAL REPLACEMENT OF FINE AGGREGATE

The construction industry, in response to environmental concerns tied to traditional methods, explores alternative materials for concrete. The study aims to investigate the strength of concrete using waste glass powder as a partial substitute for sand. Waste glass powder was varied in concrete by 10%, 20%, and 30% replacement with sand. Silt and sieve analysis tests and compressive and water absorption tests were conducted on the constituents of concrete. Findings show that the water absorption test performed on the sample of 30% replacement of sand with waste glass powder absorbed 5 times less water. Percentage replacement of 20% and 30% have compressive strengths greater than the control samples.

Hydrothermal aging and soil biodegradation characteristics of biopolymer based sustainable composites

The current research endeavor examines the water absorption (in-service life) and soil biodegradation (end-of-the-service life) behavior of short sisal fiber (SF) reinforced poly (lactic acid) (PLA) and bio-based poly (butylene succinate) (bio PBS) composites. Samples were fabricated by extrusion-injection molding with varying sisal fiber loading of 10, 20, and 30 wt%. The water absorption test was conducted in distilled water at three distinct temperatures (5, 25, and 45 °C) for 336 h. The sorption behavior of composites was studied experimentally, and detailed diffusion kinetic behavior is discussed using Fickian diffusion models. The impact of fiber content and hydrothermal temperature on water diffusion and maximum water absorption was investigated in detail. A soil burial test was conducted in local farmland soil for 60 days to determine the influence of fiber content on the biodegradation characteristics of composites. After exposure to hydrothermal aging, it was concluded that fiber loading was most significant in affecting the maximum percentage of water absorption, whereas hydrothermal temperature was more relevant for higher water diffusion. Soil burial tests showed that SF/bioPBS composites degraded quickly as compared to PLA composites. Overall, composites made with bio PBS have shown an expected response than PLA composites in terms of water absorption and soil biodegradation.

Modelling the Mechanical Effect of Salt Weathering on Historical Sandstone Blocks through Microdrilling

The durability of sandstones of historical building materials and geoheritage landforms is a major issue that requires an assessment methodology to follow salt weathering evolution. The building blocks of monuments support decorative carvings and reliefs that are outstanding testimonies of human activity. An evaluation based on quasi- and non-destructive testing is a reliable and generally accepted way of testing and inspecting historical building materials. Compression tests were performed on specimens of similar building sandstones extracted close to those of from St. Leonard’s Middle Ages Church, and microdrilling tests were carried out on adequate blocks of this monument. The locations of the latter tests were determined using the results of low-pressure water absorption tests, which contributed to finding a link between the sandstone specimens and the building blocks of the monument. This innovative methodology was used to generate simulated stress–strain diagrams of the building blocks of this church based on drilling strength results, avoiding the cutting of specimens from the façades with the sizes needed to ensure the mechanical validity of the results. A good agreement between the predicted and experimental stress–strain curves was achieved. The stress–strain curves of sound stones from historical building blocks and of their weathered envelopes are shown. The evolution of weathering profiles can be followed through the analysis of stress–strain diagrams, allowing an assessment of structural stability, which is essential to the study of the durability of historical building sandstones. This innovative methodology allows the adequate conservation of monuments and is a contribution to the knowledge of sustainable cultural tourism.

Material characterization with the fuzzy theory of particleboards bonded by urea formaldehyde with nanofillers

This study investigated the material characterization with the fuzzy theory of particleboards bonded by urea formaldehyde with nanofillers including nanofibrillated cellulose (NFC) and titanium dioxide (TiO2). The density, water absorption, thickness swelling, and mechanical tests (which included flexure and internal bonding strength tests) were considered. The fuzzy sets theory addressed the ambiguity and subjectivity of language using triangular fuzzy numbers to assess the interests of decision maker’s (DMs). The addition of nanofillers slightly decreased water absorption values due to possible good interactions between nanofillers and urea formaldehyde. Thickness swelling ranged from 0.4 to 17.5%, and water absorption ranged from 0.4 to 10.7% compared to the control sample. The physical properties of the samples were generally improved by urea formaldehyde with NFC/TiO2, and the densities of the test panels were found to be similar. The modulus of rupture of the panels with urea formaldehyde with nanofillers were under the EN 312 standard’s requirements, and the highest flexural strength and flexural modulus of elasticity were 11.1 and 1.3 GPa, respectively. Internal bond values were between 0.55 and 0.89 MPa. According to EDAS method rankings, 2C2T-8 was the best material, followed by 2C1T-8 and 2C-8. The samples coded with Control-4 and Control-8 were the lowest-performing materials.

Development of novel sustainable biocomposite from polycaprolactone and Sesbania rostrata fiber

AbstractAn efficient method to accelerate the use of polymer composites is to focus on their development as environmentally friendly materials that can naturally break down without causing any harm to the ecosystem. Hence, the primary aim of this study is to develop a biocomposite material through the fusion of Sesbania rostrata (SRF) bark fibers and the polycaprolactone (PCL) biopolymer. Various percentages (10, 15, 20, and 25 wt.%) of untreated and sodium bicarbonate‐treated SRF were incorporated into polycaprolactone to create the biocomposite samples. The composite panels were made using the compressing molding technique. Several tests were performed on the samples, such as mechanical, thermal, water absorption, wear, and morphological tests. Research has demonstrated that the strength of biocomposites composed of 20% chemically treated SRF and PCL is superior to that of other mixed materials. The thermal properties of the biocomposite remained unchanged when untreated fibers were included, but they improved when treated fibers were included. Higher water absorption properties are attributed to an increased fiber volume fraction in the biocomposites, while chemically treated fibers exhibit a notable improvement in water resistance. The wear test results indicate that the weight loss of the biocomposites is mainly influenced by the contact temperature and adhesion between the SRF surface and the PCL matrix. When examining the fractured biocomposites with a scanning electron microscope (SEM), it becomes evident that the primary reasons for failure are fiber pull‐out, debonding, and agglomeration.Highlights SR Natural fiber is chemically treated by eco‐friendly sodium bicarbonate. The treated SRF‐reinforced composites had best mechanical property. The treated SRF‐reinforced composites showed less water absorption. The composite mechanical and thermal properties had dropdown at 25 wt.% SRF. The addition of SRF reduced the weight loss of composites on wear test.

Utilization of marble waste as fine aggregate in the composition of high performance concrete containing mineral additions

This study investigates the effect of adding marble waste as fine aggregate on the properties of high-performance concrete. To achieve this objective, 10%, 20%, 30%, and 40% of marble waste fine aggregate were substituted for ordinary fine aggregate in the composition of high-performance concrete mixtures containing silica fume and ground blast furnace slag. The fresh properties were studied using slump, fresh density and air content tests, while the hardened properties were assessed using compressive and flexural strengths, ultrasonic pulse velocity, water absorption, and chemical acid attack tests. The results obtained revealed that the addition of marble waste fine aggregate significantly improved the properties of high-performance concrete and increased its resistance to chemical acid attacks. The composition-based ground blast furnace slag containing 40% marble waste fine aggregate outperformed all other compositions, increasing compressive strength by 30.98%.

Novel Collagen Membrane Formulations with Irinotecan or Minocycline for Potential Application in Brain Cancer.

Our study explores the development of collagen membranes with integrated minocycline or irinotecan, targeting applications in tissue engineering and drug delivery systems. Type I collagen, extracted from bovine skin using advanced fibril-forming technology, was crosslinked with glutaraldehyde to create membranes. These membranes incorporated minocycline, an antibiotic, or irinotecan, a chemotherapeutic agent, in various concentrations. The membranes, varying in drug concentration, were studied by water absorption and enzymatic degradation tests, demonstrating a degree of permeability. We emphasize the advantages of local drug delivery for treating high-grade gliomas, highlighting the targeted approach's efficacy in reducing systemic adverse effects and enhancing drug bioavailability at the tumor site. The utilization of collagen membranes is proposed as a viable method for local drug delivery. Irinotecan's mechanism, a topoisomerase I inhibitor, and minocycline's broad antibacterial spectrum and inhibition of glial cell-induced membrane degradation are discussed. We critically examine the challenges posed by the systemic administration of chemotherapeutic agents, mainly due to the blood-brain barrier's restrictive nature, advocating for local delivery methods as a more effective alternative for glioblastoma treatment. These local delivery strategies, including collagen membranes, are posited as significant advancements in enhancing therapeutic outcomes for glioblastoma patients.

A study on the effect of mixture constituents on washout resistance, mechanical, and transport properties in the context of underwater 3D concrete printing

Underwater layered concrete depositions, such as those obtained using 3D printing, demonstrate washout resistance, which influences layer stability, transport properties, and inter-layer mechanical strength, thus impacting its final properties. This work first focuses on understanding the compositional effect of 3D printable mortars on their washout resistance. Conventional methods for assessing washout resistance of underwater concrete are ill-suited to 3D printable materials due to different mix designs and material deposition techniques. To address this, a new protocol considering layered deposition during 3D printing was developed to evaluate the washout resistance. Interrogation of the pore structure of the printed specimens (in air and underwater environment) via water absorption and sorptivity test further establishes the influence of washout on water transport properties. The study also investigates the impact of hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA) fiber dosages on mechanical properties, including compressive strength, interlayer split tensile strength, and flexural strength. Results indicate that HPMC addition significantly improves the washout resistance, whereas PVA fibers have detrimental effect. However, optimizing the PVA fiber dosage enhances both mechanical and water transport properties of underwater printed specimen via permeable void and capillary pore structure refinement.

Impacts of corrosion inhibiting admixture and supplementary cementitious material on early strength concrete

This research aimed to evaluate the influence of alccofine 1203 on a mineral admixture and sodium nitrite as a corrosion inhibitor on the properties of concrete. To achieve these aims, an experimental investigation was carried out on a set of composite samples comprising five distinct concrete formulations. Five different mixes for the concrete were used as the overlay materials such as NC as a reference concrete, alccofine concrete (i.e. 25% cement replaced with alccofine), and alccofine concrete with varying dosages of sodium nitrite (i.e. 1%, 1.25%, and 1.5%). Alccofine reduced the workability and water absorption and increased the compressive strength of the concrete (5%) at curing age of 28 days. Adding sodium nitrite further reduced water absorption of the concrete and workability but compressive strength of 29.15% and 26.93% for the curing period of 3 and 7 days, respectively. The pH of the concrete powdered solution became more alkaline with the replacement of alccofine and addition of sodium nitrite. Free chloride content dropped by 48 and 66%, respectively, with the introduction of GGBS and sodium nitrite. Corrosion properties of the concrete samples were examined using open circuit potentials and linear polarization resistance of various concrete mixes after being immersed in 1 M H2SO4 and 3% NaCl environment. The findings indicated a notable improvement in the corrosion resistance, water absorption test, thermal conductivity, strength properties, and microstructural properties of concrete with the incorporation of SN in combination with alccofine. The application of the response surface method allowed for the prediction, validation, and optimization of experimental data using a regression equation.

Exploring the Use of Iron Ore Tailings in Concrete by Partial Replacement of Fine Aggregates

Concrete is the most durable, resilient, available and affordable material in the built environment. The manufacture of large quantities of iron ore has created difficulties for the environment and disposal. The utilization of IOT as fine aggregate in building material production is relatively feasible. Experiments were conducted to determine the suitability of iron ore tailings as replacement of fine aggregates for concrete. The iron ore waste was collected from Gua Iron Mines, Singhbum. Mix Design was carried out for concrete of grade M35 using standard practice for selecting proportions for normal weight. Iron ore waste replaced with fine aggregates in mixes by 30% and 35% respectively. The materials used for M35 grade of concrete is coarse aggregate 10-20mm, fine aggregate is of Zone 2, cement of 53 grade. Tests were performed on materials, for cement and fine Aggregate Fineness test, Specific Gravity were performed. Water absorption test, specific gravity, Impact value these were performed for Coarse aggregate. It was observed that compression values of concrete for 30% for 3 days its 13.703 Mpa, For 7 days its 16.503 Mpa, and for 28 it was 28.033 Mpa

Performance evaluation of kevlar fiber reinforced epoxy composite by depositing graphene/SiC/Al2O3 nanoparticles

The synergistic effect of adding Silicon Carbide (SiC), Aluminum Oxide (Al2O3), and Graphene (GR) nanoparticles into Kevlar fiber-reinforced epoxy composites is investigated in this study. Within the epoxy matrix and Kevlar fibre reinforcement, these nanoparticles come in a variety of compositions. The mechanical and flammability features of the composite are revealed by experimental evaluation. Of the nanoparticles, graphene performs the best; the composite reinforced with graphene shows 324 MPa of tensile strength, 8 J/mm of impact strength, and 75.2 HRC of hardness. The composite layers' interior structure is investigated using scanning electron microscopy examination. To evaluate thermal stability of the composition the thermogravimetric (TG) and the differential thermal analysis (DTA) investigations were performed. Thermal stability is achieved by the graphene-reinforced composite at 775 °C. Additionally, corrosion tests and water absorption tests were conducted to assess the material's moisture sensitivity. The overall goal of the research is to ascertain whether adding various nanoparticles to Kevlar produces the best outcomes; graphene has demonstrated promising results in terms of improving mechanical and thermal stability.

Recycled foam concrete masonry and porcelanite rocks-based lightweight geo-polymer concrete at elevated temperatures

This study investigated the mechanical and microstructural properties of lightweight aggregate geo-polymer concrete (LWAGC) produced by alkali-activating glass powder (GP) and Fly Ash (FA) at elevated temperatures ranging from 200 to 800°C. It also examined the effects of incorporating crushed foam masonry (RFA) and crushed porcelanite rock aggregates (PA) into FA and GP-based geo-polymer concrete, both before and after exposure to ambient and high temperatures. A low-calcium type of FA was used as a binder in the geo-polymer concrete paste, with a 10 % replacement of glass powder. The concrete samples were heated at temperatures of 200°C, 400°C, 550°C, and 800°C for a duration of 60 minutes, with a heating rate of 7°C per minute. It was observed that the inclusion of weaker coarse aggregate resulted in a reduction of the compressive strength of the concrete. The geo-polymer concrete was subjected to tests for water absorption, mass loss, cracking, and microstructure analysis at elevated temperatures. The findings indicate that at heating temperatures of 400°C and above, the geo-polymer concrete underwent degradation and dehydration. The test findings also revealed residual compressive strengths of 104.9 %, 97.2 %, 81.8 %, and 64.2 % for the (RFA) types, and 107.3 %, 94.8 %, 78.3 %, and 58.8 % for the (PA) types. Additionally, the density decreased by 1.02 %, 4.88 %, 8.10 %, and 13.88 % for (RFA) and (PA) types, respectively, and by 0.27 %, 1.91 %, 4.67 %, and 10.79 % overall. The results indicate that the compressive strength of the concretes increased after exposure to elevated temperatures of 35°C and 200°C. However, when exposed to temperatures ranging from 400°C to 800°C, the strength of the LWAGC started to degrade and decline. Based on the obtained findings, the present study recommends performing laboratory tests on construction waste generated during demolition while developing and evaluating numerical models that predict the behavior of the resulting demolition materials when incorporated in the production of geo-polymer concrete.

Study of Physical Properties and Alterability of Natural Stones and Artificial Agglomerated

Objective: This work aims to evaluate the physical and alterability properties such as resistance to staining and chemical attack of two natural stones (Siena White and White Marble) and two artificial agglomerated stones (Aldan White and Galaxy White), using Brazilian technical standards as methodology. ABNT NBR 15845 (2015), NBR 16596 (2017) and NBR 10545 (2017). Theoretical Framework: Ornamental stones, such as granite, marble and quartzite, are valued in construction and decoration for their durability and natural beauty. Artificial agglomerated stones are industrially produced to imitate the appearance of natural stones, offering additional advantages such as greater uniformity and resistance. Both options have their various aesthetic and functional applications. Method: Ten specimens measuring 60 x 60 x 20 mm were used for each material. Apparent density, apparent porosity and water absorption tests were carried out. To determine resistance to chemical attack, ABNT NBR 16596 (2017) was used, where the stones were exposed to a variety of chemical agents. The determination of stain resistance was carried out according to the ABNT NBR 10545-14 (2017) standard in an adapted form. The samples were exposed for 24 hours to penetrating agents and household products. Subsequently, the material was classified according to the ease of removing stains, after the cleaning steps described in the standard. Results and Discussion: The results showed that natural stones and artificial agglomerates were satisfactory in meeting the requirements of the ABNT NBR 15844 (2015) standard, as the lower porosity and reduced water absorption generally make these materials more durable and easier to maintain, especially in environments where the Exposure to moisture and liquids is an important factor, such as in kitchens and bathrooms. Research Implications: Evaluate the physical indices, staining and chemical attack of natural stones and artificial agglomerated stones produced by the industry. Originality/Value: Carry out tests on natural stones and artificial agglomerates in materials sold in industry and certify their technological characteristics through tests established by Brazilian standards.

Extracting and characterizing novel cellulose fibers from Chamaerops humilis rachis for textiles' sustainable and cleaner production as reinforcement for potential applications

New cellulose (CL) fibers are derived from Chamaerops humilis (Ch) rachis. They play an essential role in various industries to produce environmentally friendly products as an alternative to enhancing and strengthening lightweight composites, such as dashboards automotive. Distinctive properties of Ch fibers (ChFs) were determined by extracting fibers from dwarf palm plant branches using anaerobic analysis. This search comprehensively studies morphological, physical, mechanical, and thermal characteristics and water absorption testing. The fiber diameter was 241.23 ± 34.77 μm, while the obtained linear density and density were 13.71 ± 0.57 Tex and 0.801 ± 0.05 g/cm3, respectively. The moisture content was 8.5 %, and the moisture regain was 9.29 %. Scanning electron microscopy images showed the fibers and smooth and rough surfaces. The thermogravimetric analysis demonstrated the maximum degradation of 352 °C, thermal stability of 243 °C, and the kinetic activation energy reached (79.78 kJ/mol). X-ray diffraction proves the availability of CL, with a crystallinity index = 68.38 % and crystal size = 2.92 nm. Fourier transform infrared succeeded in detecting functional groups and chemical compounds of fibers. The fibers exhibited a tensile stress of 110.85 ± 77.08 MPa, an elongation at a break rate of 2.29 ± 1.27 %, and Young's modulus of 6.05 ± 3.9 GPa. The maximum likelihood method (2P-Weibull distribution) was employed to examine the distribution of mechanical properties of fibers. According to the results above, new ChFs are an excellent reinforcement for elaborating fiber-reinforced biocomposites.

Bridging gap between agro-industrial waste, biodiversity and mycelium-based biocomposites: Understanding their properties by multiscale methodology

A multiscale methodology approach was employed integrating microscopic analysis of the biomasses present in the biocomposite (lignocellulosic and fungal) to understand their macroscopic response in terms of physical and mechanical properties. Colombian native strain Ganoderma gibbosum, used for the first time in the production of biocomposites was cultivated on peach palm fruit peel flour and sugar cane bagasse wet dust, individually and as a mixture. During the solid-state fermentation were monitoring the change that occurred in substrate composition such as glucan, arabinoxylan, and lignin through biomass compositional analysis using structural carbohydrates and lignin. Moreover, fungal biomass formation was monitored via scanning electron microscopy. The resulting biocomposites underwent characterization through flexural and water absorption tests. Our findings indicated that G. gibbosum primarily degraded the polysaccharides in each of the evaluated media. However, lignin degradation to 15.06 g/g was only observed in the mixture biocomposite of peach palm fruit peel fluor and sugarcane bagasse wet dust in a ratio of 1꞉1, accompanied by a reduction in glucan and arabinoxylan weights to 26.1 and 7.72 g/g, respectively. This polymer degradation, combined with a protein-rich source in the mixture biocomposite of peach palm fruit peel fluor and sugarcane bagasse wet dust in a ratio of 1꞉1, facilitated the production of a fungal skin (biological matrix) with a high hyphal density of 65 %, contributing to Young's modulus of 3.83 MPa, elongation without failure, and low water absorption rate in this biocomposite (55 %). The lignocellulosic biomass in the culture media acted as a filler for mechanical interlocking with the matrix and provided attachment points for water absorption. Thus, our study establishes a connection between the microscopic scale and the macroscopic behavior of this biocomposite, assessing structural carbohydrates and lignin analysis during solid-state fermentation (SSF), laying the groundwork for a more customized design of mycelium-based biocomposites. Finally, this study demonstrates the possibility of tailoring nutrient composition by designing their culture media to obtain physical-mechanical properties according to the application requirement.

Water absorption and property evolution of epoxy resin under hygrothermal environment

Changes in structure and properties of resin matrix caused by water absorption is one of the key factors affecting the long-term durability of fiber reinforced polymer composites used in civil engineering. In the present study, the water diffusion and structural change in an epoxy resin were investigated experimentally through immersion in deionized water at 40, 60 and 80 °C for 135 days. Water absorption, thermal, mechanical and microstructure analysis tests were conducted to evaluate the long-term property evolution. It was found that the water absorption of epoxy resin followed a two-stage model, including an initial Fick's diffusion response and a subsequent relaxation response. Long-term hygrothermal exposure brought about the structural change of epoxy resin, which led to the significant degradation up to 8%–30% in the mechanical properties and 21% in glass transition temperature, respectively. The resin plasticization and hydrolysis was the key factors for the degradation of thermal and mechanical properties. It was proved that the plasticization effect was reversible with the remove of bonding water after the drying. Based on the Arrhenius equation, the long-term life of flexural strength in two service environments were predicted to provide the application guideline. The significant degradation of flexural strength was occurred at the initial exposure of 2000 days and then reached to the stable strength retention of 69.6%.

Lightweight rPPU Eco-block Using Recycled Plastic (rP) and Polyurethane (PU) for Soft Subgrade Soil Stabilisation

The stability of the soil plays a crucial role in the safety and longevity of various civil engineering structures. However, problematic soil conditions, such as clay soil and peat soil, often pose challenges due to their high-water content, poor strength, low bearing capacity, and high compressibility. This research focuses on addressing these challenges by utilizing lightweight fill materials as an effective solution for backfilling applications. The study aims to investigate the characteristics and performance of a novel lightweight fill material using recycled plastic (rP) and polyurethane (PU) known as rPPU ecoblock. The eco-block is mainly fabricated using recycled plastic bottles, recycled plastic packaging, and polyurethane, offering a sustainable approach to waste management and construction materials. To achieve the research objectives, a series of experiments will be conducted. The strength and density of plastic bottles filled with recycled plastic packaging will be analyzed, providing insight into their mechanical properties. Furthermore, the water absorption and buoyancy of the lightweight rPPU eco-block are evaluated, considering its suitability for various construction scenarios. The research findings contribute to the understanding of the physical and mechanical characteristics of the rPPU eco-block, providing valuable information for its potential application as a backfill material. The compressive strength, water absorption, and buoyancy tests conducted per ASTM standards provide quantitative data on the eco-block's performance. The use of lightweight fill materials, particularly the rPPU eco-block, offers benefits such as reduced embankment self-weight, improved stability, and minimized environmental impact. Moreover, the recycling of plasticwaste contributes to the circular economy and aligns with sustainable development goals (SDG): SDG9 and SDG11. The results of this research provide valuable insights for engineers, construction professionals, and stakeholders involved in geotechnical and civil engineering projects.

The Development of Edible Straw from Apple and Durian Peel

Over the past few decades, there has been a surge in the demand for plastic utensils, especially plastic straw which contribute to consumption of toxic chemicals. The use of plastic straws has led to plastic pollution crisis due to their non-biodegradability and lengthy decomposition periods. Currently, various kinds of edible straw have been developed to replace traditional plastic straw to reduce the environmental pollution, however the edible straw usually has weak structural integrity and becomes soggy when immersed in beverages. The purpose of this study is to develop the production of edible straw from fruit peel, such as apple and durian peel skin and investigate the physicochemical characteristics of the edible straw at different temperatures. The manufacturing process of edible straw using fruit peel can be categorized into 3 main steps, including preparation of fruit peel paste using fruit peel and distilled water at weight ratio 1:0.3, preparation of edible film as well as drying and demoulding of edible straw. Then, a series of tests including water absorption test, heat resistance test and swelling ratio test have been conducted to investigate the functionality of the edible straw in different kinds of beverages, including hot and cold liquids at temperature ranges from 5 °C to 65 °C. The observation suggests that durian peel edible straw has higher water absorption capability, heat resistance and swelling ratio when soaked in liquids compared to apple peel edible straw. Both the apple and durian peel edible straw are best for use at beverage temperature within 25 °C. Durian peel edible straw has better performance as it can be used for beverage temperature up until 65 °C while only 45 °C for apple peel edible straw.

Assessment of green biocomposites based on polyvinyl alcohol and grafted biopolymer tamarind kernel powder with polyacrylic acid

This investigation focuses on the development and assessment of biopolymer-based green biocomposite materials that contain tamarind seed kernel powder (TKP) either in its raw or polyacrylic acid (PAA) grafted form as the reinforcing component, combined with polyvinyl alcohol (PVA) as the matrix material. The goal is to develop biopolymer TKP based green biocomposites with a biodegradable PVA matrix for food grade packaging and biomedical applications. Both raw TKP reinforced PVA and PAA grafted TKP reinforced PVA, two forms of sustainable green biocomposites, were developed. Compression molding was used to combine various raw or PAA grafted TKP loadings with PVA to produce various biocomposites. The loadings were 0 %, 0.25 %, 0.5 %, 1 %, 5 %, and 10 % in weight. To confirm the PAA grafted TKP, attenuated total reflection-fourier transform infrared (ATR-FTIR) spectrum analysis was employed. The mechanical properties of the biocomposites were examined, and it was discovered that the grafted biocomposites exhibited 4 % higher tensile strength and elongation at break (%) on average than the raw TKP reinforced PVA biocomposites. The Charpy impact strength of the biocomposites exhibited an average 28 % improvement in impact resistance with modified TKP and an 8 % increase with raw TKP when compared to pure PVA sheets. Additionally, the PAA-grafted TKP reinforced PVA biocomposites outperformed the raw TKP reinforced PVA biocomposites in water absorption tests, exhibiting an average improvement in moisture resistance of nearly 13 %. Scanning electron microscopy (SEM) tests revealed that the PAA-grafted biocomposites had a more uniform dispersion of fillers inside the PVA matrix as compared to the raw TKP/PVA biocomposites. These findings enable in the development of high-performance, environmentally friendly and green biocomposite materials for a variety of uses.