Enhancement Of Modulus Research Articles

Enhancing the Mechanical and Adhesive Properties of Polyurethane Adhesives with Propylene Oxide-Modified Ethylenediamine (PPO-EDA)

This study explores the use of propylene oxide-modified ethylenediamine (PPO-EDA) as a novel crosslinker and chain extender in polyurethane (PU) adhesives. PPO-EDA was synthesized and compared with N,N’-dimethylethylenediamine (DMEDA) to assess its impact on mechanical properties and adhesion performance. Key parameters such as NCO conversion, tensile strength, and lap shear strength were thoroughly evaluated. The results demonstrated that incorporating PPO-EDA significantly improved NCO conversion and crosslink density, leading to notable enhancements in tensile strength and elastic modulus compared to DMEDA. Lap shear tests further revealed superior adhesion performance in PPO-EDA-modified PU adhesives, particularly on amine silane-treated steel substrates, where lap shear strength consistently outperformed other samples. This improved performance was attributed to PPO-EDA’s dual role as a chain extender and crosslinker, which strengthened the adhesive’s structural integrity. This study underscores the effectiveness of PPO-EDA as a modifier for enhancing both mechanical and adhesive properties in PU-based adhesives, offering a promising solution for optimizing high-performance adhesives in automotive and industrial applications.

Experimental Study of Influence of Plant Roots on Dynamic Characteristics of Clay

Conducting research on the dynamic behavior of root–soil systems is crucial for accurately assessing the seismic response of ecological slopes, thereby providing a scientific foundation for the development of appropriate seismic design measures. Documentation of the improvement of soil dynamics through vegetation root systems is insufficient in the current research. This study utilizes resonance column tests to explore how root systems influence the dynamic properties of clayey soil and to uncover the mechanisms behind this enhancement. The results indicate that both root distribution and mass density have a significant impact on the soil’s dynamic shear modulus and damping ratio. When roots are distributed in the upper part of the soil, the dynamic shear modulus and damping ratio of the soil are higher than in cases of even distribution or concentration in the lower part. The dynamic shear modulus initially increases and then decreases with the increase in root mass density, reaching its peak at a root mass density of 1.5% g·cm−3. The damping ratio is influenced by both root mass density and confining pressure, with different critical root mass densities observed under varying confining pressures. The maximum enhancement in dynamic shear modulus is 27.6%, achieved at a 3% root mass density, with a peak damping ratio of 5.39%. Variations in both dynamic shear modulus and damping ratio with shear strain follow the Hardin–Drnevich hyperbolic curve.

Novel hybrid polymer composites for optimized thermal performance in electric vehicle battery cases

AbstractElectric vehicles are essential for ensuring the sustainability of transportation and have the advantage of emitting no environmentally harmful gases due to their non‐reliance on fossil fuels, such as internal combustion engines. However, battery performance remains a significant barrier to wider use of electric cars, as the joule effect increases temperature, negatively impacting battery efficiency. The objective of this study is to create polymer‐based hybrid composite materials that enhance the thermal conductivity and impact strength of the battery module. Polyamide 6 (PA6) was chosen as the matrix material because of its extensive usage and ease of fabrication. Hexagonal boron nitride (h‐BN) and graphene nanoplatelets (GnPs) were used to enhance thermal conductivity. Furthermore, a Styrene‐ethylene‐butylene‐styrene (SEBS) elastomer supplement has been included to enhance protection against probable ground impact damage. After production, samples underwent mechanical and thermal testing. The addition of GnPs led to an 8.9% enhancement in the elastic modulus and a 4.97% improvement in the tensile strength value. The results demonstrate that the thermal conductivity had a significant rise of 194.3% when 30% h‐BN was incorporated based on weight. Subsequently, fracture surfaces were examined using a scanning electron microscope (SEM) to analyze the mechanisms that caused the damage. Afterwards, the thermal conductivity of the compositions was determined utilizing analytical methods and by creating a representative volume element (RVE). In the end, the compositions were evaluated based on several qualities, resulting in the selection of the most suitable composition by using the response surface method (RSM) and python‐based optimization code.Highlights Incorporating 30% h‐BN into the neat matrix increased the thermal conductivity by 194.3%. Optimization studies showed that 30% h‐BN reinforcement led to the most preferred results. GnP addition improved mechanical properties. GnP and h‐BN reinforcements improve the composites' glass transition temperature.

Plasma sprayed Titanium- Nanodiamond composite coatings with enhanced mechanical properties

This research aims to investigate the mechanical properties of plasma-sprayed Ti-nanodiamond (Ti-NDs) composite coatings, leveraging the zero-dimensional structure, outstanding mechanical properties, and remarkable chemical and thermal stability of nanodiamonds (NDs) as a prudent choice for enhancing the mechanical properties of Ti coatings. The deposited coatings were tested for their mechanical properties, including Ultimate Tensile Strength (UTS), Yield Strength (YS), Hardness, and Elastic Modulus. The relative density of the coatings experienced a substantial increase with the addition of NDs, from 82.31% to 94.79% for 1wt%. This improved relative density was attributed to the effective melting of powders under the plasma plume facilitated by the presence of NDs having higher thermal conductivity. Consequently, a remarkable improvement of 22.7% in UTS and 20.5% in YS, accompanied by a considerable enhancement in hardness (20%) and elastic modulus (26.7%). These enhancements in the coating properties are credited to the excellent mechanical properties and higher thermal conductivity of NDs, facilitating the uniform melting of the Ti matrix and, consequently, leading to improved density and the formation of TiC within the coatings.

Improving physicochemical properties and gel formation mechanism of nutty plant-based yogurt with Tremella fuciformis polysaccharides

Developing nutty plant-based yogurt (NPBY) with desired texture and sensory properties has been challenging. This study sought to investigate the effects of Tremella fuciformis polysaccharides (TFPS) on the physicochemical, textural, rheological, and microstructural properties of NPBY. The introduction of TFPS enhanced the accumulation of organic acids, water holding capacity, and antioxidant activity. The firmness of NPBY with 0.85 % TFPS increased from 187.77 × 10−3 N to 259.90 × 10−3 N, with significant enhancements in elastic modulus (G′, G′′) and apparent viscosity. Furthermore, the introduction of 0.85 % TFPS significantly improved liking scores in sensory evaluations. Microstructural analysis revealed that TFPS promoted the formation of proteins and oil body clusters, resulting in a more compact gel network. The synergetic effects of electrostatic and hydrophobic interactions were identified as primary driving forces for NPBY gel formation. This study provides valuable insights into the role of natural polysaccharides in strengthening plant-based yogurt gel.

Enhancement of Resilient Modulus and Strength of Expansive Clay Stabilized by Wool and Agricultural Waste

Enhancement of Resilient Modulus and Strength of Expansive Clay Stabilized by Wool and Agricultural Waste

Comprehensive study of Tolanene's mechanical properties: Effects of temperature, layering, orientation, and defects

This study explores the mechanical properties of both single-layered and multi-layered tolanene nanosheets via molecular dynamics (MD) simulations. The effects of critical parameters such as size, temperature, and defects on the mechanical behavior of armchair and zigzag configurations of single-layer Tolanene nanosheets are analyzed. Key mechanical properties, including Young's modulus, ultimate stress, fracture stress, and fracture strain, are evaluated based on the stress-strain curve. It is observed that the zigzag configuration exhibits a higher Young's modulus compared to the armchair configuration. However, the armchair structure shows greater ultimate stress than the zigzag configuration. An increase in temperature or the introduction of vacancy defects leads to a degradation of mechanical properties in both configurations. The sensitivity of Young's modulus to temperature is more pronounced in the zigzag configuration than in the armchair, even though the armchair configuration generally has a higher Young's modulus. Additionally, increasing the number of layers in the nanosheets results in an enhancement of Young's modulus, with the armchair configuration showing more significant improvement than the zigzag configuration. The variation in Young's modulus with increasing layers is minimal for the zigzag configuration.

Geosynthetic-stabilized aggregate: quantitative modulus evaluation via Bender Element

Geosynthetics, mainly geogrids and geotextiles, are commonly used to mechanically stabilize unbound aggregate layers in paved road applications. They provide lateral restraint to aggregates to initially increase the layer modulus during construction and minimize its time-dependent decrease under vehicular traffic loading. Different types of geosynthetics may provide different improvement mechanisms and stiffness enhancement levels. Quantitative evaluation of various stabilization geosynthetics is presented herein to compare modulus improvement trends and help incorporate geosynthetic benefits into state-of-the-art mechanistic-empirical (M-E) pavement design procedures. Five geogrids (three extruded, one woven, and one welded) and two geotextiles (one woven and one nonwoven) were studied with a dense graded aggregate in laboratory triaxial testing. Geosynthetics were placed at specimen mid-height and three pairs of Bender Element (BE) sensors were placed at various heights above the geosynthetic to collect shear waves and quantify the degree of mechanical stabilization during resilient modulus testing. While resilient moduli did not distinguish effectiveness of different geosynthetics, shear wave measurements could clearly show local stiffness increases achieved with geosynthetic inclusions. Meanwhile, trends observed in shear modulus profiles at various distances from the geosynthetic, when compared to that of control specimen, properly established the modulus enhancement level achieved in mechanical stabilization with geosynthetics.

Enhanced high-temperature energy storage performance in all-organic dielectric films through synergistic crosslinking of chemical and physical interaction

Advanced electronic devices and energy systems urgently require high-temperature polymer dielectrics that can offer both high discharge energy density and energy storage efficiency. However, the capacitive properties of most polymers sharply deteriorate at elevated temperatures, due to the significant rise in leakage current density and energy loss. Herein, a new design approach is adopted to fabricate high-temperature polyetherimide (PEI) dielectrics with chemical and physical cooperative crosslinking networks, the dual-crosslinked PEI dielectrics are prepared through amine crosslinking agent and the electrostatic interaction of oppositely charged phenyl groups between triptycene (TE) and PEI chain segments. Benefiting from the increased crosslinking sites, the dual-crosslinked PEI films achieve the simultaneously enhancement in Tg, modulus and bandgap compared to un-crosslinked and single-crosslinked polymers. Meanwhile, the PEI with dual-crosslinked network displays higher chain packing density, effectively reducing the mean motion pathways of charge carriers and the conduction loss inside polymer dielectric. Consequently, the dual-crosslinked PEI containing 0.25 wt% TE delivers an outstanding discharge energy density of 2.69 J/cm3 and retains excellent cyclability after 100,000 charge–discharge cycles at 200 ℃. Additionally, finite element analysis and molecular dynamics simulation further confirm that less Joule heat and tighter chain structure are formed in the dual-crosslinked polymer dielectric. This research offers a novel methodology to prepare high-performance polymer dielectrics for high-temperature applications.

Green transforming black liquors as a new HCHO scavenger in production eco urea formaldehyde-agro composites

Innovative formaldehyde (HCHO)-scavenger based on black liquor is being developed to achieve eco-friendly low toxic urea formaldehyde (UF) adhesive. This scavenger will enhance the UF adhesive in production of agro-composites, complying with the environmental requirements. The HCHO-scavenger is synthesized from black liquor-based aerogels of various types of black liquors. The performance of the prepared scavengers is assessed via adsorption of HCHO; as well as its beneficial effect on properties of UF adhesive and UF-Palm fiber-composite. In order to produce a composite with mechanical properties and free-HCHO compliance with the standard specifications, the UF-scavenger system is optimized from its behavior. The data evidence the effective behavior of all investigated scavenger to improve bond strength of UF adhesive system (from 8.4 MPa to ∼ 18 MPa); and properties of UF-palm-composites, where the enhancement in modulus of rupture (MOR) and internal bond strength (IB), water repellent, reach to 50 %, 83 % and 7.7 %, respectively. In addition to success in producing eco-composites through reducing the free-HCHO of wood sample from 30.77 to 3.0–12.7 mg/100g with reduction percentages (58.7–90.3 %) exceeded those reported in the literature when carbon and silicon scavengers were used.

Thermo‐mechanical performance of oil palm/bamboo fiber reinforced bio epoxy hybrid composites

AbstractThe aim of this work to fabricate bamboo (B)/oil palm (O) fibers based biocomposites to assess mechanical, thermal and morphological properties. Flexural strength and modulus of hybrid biocomposite (7B:3O) exhibited a higher value (71.18 MPa and 5.24GPa) respectively among all biocomposite samples. On the other hand, pure biocomposite (B) showed a higher impact strength value (6977.8 J/m2) compared to other biocomposites. The results of TGA showed that thermal stability was observed significantly for hybrid biocomposites compared to other samples. In addition, the maximum decomposition temperature values were displayed in the hybrid biocomposite (5B5O), which was 377.82°C. Through DMA, it was likely to find the storage modulus curves (E′), loss modulus (E″) and damping factor (tan δ) for the biocomposites. The E′ showed an increase in the (3736.84 MPa) contrasted to other corresponding samples which were 3121.81 MPa, and 3209.67 MPa for 3B7O MPa and 5B5O samples, respectively. Overall, the results of DMA displayed an enhancement in the storage modulus (E′) in terms of the hybrid biocomposites representing greater stiffness and lower damping factor. SEM micrographs were utilized to understand the fiber bonding and fiber adhesion with the epoxy matrix. Furthermore, it confirmed SEM results that hybrid natural fibers enhance the complete characterisations of bio‐epoxy materials. Additionally, SEM images of the tensile fracture surfaces discovered voids and cracks. Finally, it can be concluded that the selection for the developed hybrid biocomposites provides excellent and economical lightweight biomaterials for automotive, aerospace, contractions and building components.Highlights Green hybrid biocomposites by oil palm/bamboo fiber/bioepoxy resin. Mechanical, thermal, DMA of hybrid composites carried out. Hybrid biocomposite(7B:3O) exhibited higher flexural strength value (71.18 MPa). TGA showed that the biocomposites are thermally further stable. DMA displayed an enhancement in the storage modulus (E′).

Impact of molecular architecture and draw ratio on enhancement of targeted mechanical properties of machine direction oriented polyethylene films produced after blown film extrusion

Conventional multi-material multi-layer flexible packaging offers excellent properties. However, it has recycling challenges, necessitating a shift to mono-material multi-layer flexible packaging for example all-polyethylene (PE) packaging which can be tailored through various synthesis and processing methods for different layers. In this work, we study how the key molecular properties (number-average molecular weight ( Mn), weight-average molecular weight ( M w), molecular weight distribution (MWD), comonomer content (short chain branching)) and machine direction orientation (MDO) process draw ratio (MDX) influence the final morphology and mechanical properties of MDO-PE films which are intended as the outer layer of mono-material all-polyethylene multi-layer flexible packaging. Five PE grades and various blends were extruded and blown into films. Selected blown films were machine direction oriented to obtain the final MDO-PE films. Furthermore, one selected PE blown film was processed at different MDO process draw ratios while keeping other process parameters constant. From the molecular properties point of view, the higher molecular weight fractions provide a higher possibility for uniform stretching whereas lower molecular weight fractions provide a higher natural draw ratio and therefore higher modulus and stiffness enhancement. Further, the results show that increasing MDO process draw ratio leads to more fibrillation and increased crystallinity. Consequently, the tensile modulus and stiffness at the higher draw ratios increase as well and are comparable to conventionally used polymers in outer layers of multilayer flexible packaging. Thus, this work demonstrates that MDO-PE films with enhanced modulus can provide sufficient stiffness for the design of outer layer of mono-material multi-layer all-PE packaging which presents higher potential for mechanical recyclability.

Influence of HEA reinforcement on pulse electric current sintered Aluminium Composites: Microstructure, Density, and nanomechanical properties

This study investigates how different compositions of high-entropy alloys (HEAs), known for their strength and thermal stability, affect the microstructure, density, and nanomechanical properties of aluminium matrix composites produced by pulse electric current sintering (PECS). Commercial aluminium was reinforced with 5%, 7%, and 10% HEA and sintered using PECS. Microstructural analysis showed improved particle bonding and dispersion, resulting in enhanced mechanical properties. Although relative density slightly decreased with higher HEA content, there was a significant enhancement in nanohardness and elastic modulus. The composites exhibited improved resistance to plastic deformation and increased stiffness, thus, highlighting the effectiveness of HEA reinforcement in optimizing aluminium composites for high-strength, lightweight, and advanced engineering applications. These findings offer valuable insights for developing next-generation materials suited to demanding engineering environments.

Laser powder bed fusion of SiC particle-reinforced pre-alloyed TiB2/AlSi10Mg composite with high-strength and high-stiffness

Recently, laser powder bed fusion (LPBF) of particle-reinforced aluminum matrix composites (PAMCs) with high-strength and high-stiffness have attracted extensive attention in aviation and aerospace. However, performance improvement of single or dual PAMCs using traditional mechanical mixing method is still limited. Therefore, this study innovatively employed pre-alloyed ∼6.5 wt% TiB2/AlSi10Mg composite as the matrix and mechanically mixed SiC particles with different contents (5 vol% and 10 vol%) to fabricate dual PAMCs with high particles content through LPBF. The results indicated that the 5 vol% SiC+TiB2/AlSi10Mg composite revealed relatively weak agglomeration effect of SiC particle and highest relative density (∼99.1 %), thus exhibiting optimal processability. Using this composition material as the research object, it was found that the microstructure maintains the basic features of pre-alloyed TiB2/AlSi10Mg composite except for the slight grain coarsening. However, SiC particles react with α-Al matrix and Al3Ti. Then Al4C3 and TiC enhancement phase were formed, and micron-sized Si particles precipitated within the Al cells surrounded by the eutectic Al-Si. More importantly, due to novel preparation method of dual PAMCs powder, simultaneous enhancement in ultimate tensile strength (∼554.0 MPa), yield strength (∼376.0 MPa), and elastic modulus (∼97.4 GPa) was achieved. Total particle content (∼14.0 wt%) and tensile property were higher than those of reported other PAMCs processed by LPBF. Finally, expect for the fracture characteristics inherent to the pre-alloyed TiB2/AlSi10Mg composite, new fracture mechanism for the tearing of SiC particles was exhibited. This work provides new insights into the preparation of high-strength and high-stiffness PAMCs processed by LPBF.

Recovery of carbon fiber from carbon fiber reinforced polymer waste via microwave molten-carbonate pyrolysis

In recent years, the increased use of carbon fiber-reinforced polymer (CFRP) composites has led to a significant rise in waste production. To address this issue, a recycling method using microwave molten salt pyrolysis-oxidation has been proposed to efficiently process CFRP and obtain regenerated carbon fibers (RCFs) under the combined effect of microwave and Na2CO3/K2CO3/Li2CO3 composite molten salt. The mechanism of microwave molten salt pyrolysis was examined in conjunction with the pyrolysis products (pyrolysis oil and gas), furthermore, the microwave molten salt pyrolysis process was optimized. The causes of the changes in the mechanical characteristics and wettability of carbon fibers (CFs) were additionally investigated and analyzed. The RCFs recovered from previous composite materials were processed into new composite materials and mechanically tested to assess their reusability. The study found that using microwave pyrolysis at 350°C for 10 min followed by oxidation at 450°C for 20 min resulted in recovered carbon fibers (RCFs) that retained 98.81 % of the tensile strength of the virgin carbon fibers (VCFs). Additionally, the RCFs showed a tensile modulus enhancement of 14.70 %, with the recovery ratio of carbon fibers as high as 98.44 %. Pyrolysis generates combustible gases like hydrogen (H2), carbon monoxide (CO), and alkanes, alongside products primarily composed of phenols and aromatic compounds. The recycling method can quickly recover high-performance carbon fibers and valuable pyrolysis by-products from CFRP waste, making them highly valuable for resource recycling and the sustainable development of carbon fiber materials.

Effect of fiber loading on the mechanical, morphological, and dynamic mechanical characteristics of Calamus tenuis fiber reinforced epoxy composites

AbstractThis research delves into incorporating Calamus tenuis fibers as reinforcing material in polymer composites, conducting a thorough analysis of their viscoelastic, mechanical, and morphological attributes. Employing the hand layup method, Calamus tenuis fiber‐reinforced epoxy composites were crafted across a range of fiber loadings from 0 to 25 wt% with 5 wt% increments. Results highlight significant enhancements in mechanical attributes upon the incorporation of Calamus tenuis fibers into the matrix. Notably, the composite with 10 wt% Calamus tenuis fibers emerges as the top performer, showcasing unparalleled mechanical strength compared to neat epoxy. It achieves the highest tensile strength (21.08 ± 1.03 MPa) and tensile modulus (2.84 ± 0.09 GPa), along with the utmost flexural strength (63.31 ± 1.05 MPa) and flexural modulus (3.12 ± 0.16 GPa). Furthermore, it demonstrates remarkable impact strength (9.40 ± 0.40 J/cm2), emphasizing its resilience. Scanning electron microscopy (SEM) analysis confirms enhanced fiber‐matrix adhesion in the 10 wt% composite. Additionally, dynamic mechanical analysis (DMA) results reveal enhancements in storage and loss modulus, with the 10 wt% composites exhibiting the highest values. However, the damping factor decreases with the inclusion of Calamus tenuis fibers. Overall, a 10 wt% fiber loading is deemed ideal for enhancing the mechanical and dynamic properties of epoxy composites.Highlights Utilized Calamus tenuis fibers as reinforcing materials in epoxy composites. Investigated the mechanical, morphological, and viscoelastic properties. Calamus tenuis fibers boost epoxy composite mechanical traits significantly. SEM confirms improved fiber‐matrix adhesion in 10 wt% composite. DMA highlights elevated storage and loss modulus in 10 wt% composites.

Fabrication of kenaf fiber reinforced boron carbide fillers embedded epoxy matrix composite – An antimicrobial and structural analysis

This study investigates the incorporation of boron carbide (B4C) filler particulates into a kenaf fiber-reinforced epoxy matrix to explore its potential in lightweight applications, focusing on antimicrobial effectiveness, mechanical integrity, thermal properties, and microstructural characteristics. The composite material was formulated by blending varying seven different concentrations of boron carbide (0–50 g) and kenaf fibers (KFs) with an epoxy resin, aiming to achieve a balance between mechanical strength and minimal weight. Antimicrobial test revealed that the composite material, consisting of kenaf fiber reinforced with B4C particulates, exhibited significant antibacterial activity against common pathogens. Mechanical testing indicated that the addition of boron carbide and kenaf fibers significantly improved the tensile strength and flexural rigidity of the composites. Specifically, enhancements in tensile strength and flexural modulus were quantitatively analyzed, showing notable increases compared to the base epoxy resin. Scanning Electron Microscopy (SEM) was employed to examine the fracture surfaces following mechanical testing, revealing improved interfacial bonding between the kenaf fibers and the epoxy matrix due to the presence of boron carbide. This microscopic analysis also highlighted areas where stress distribution was optimized, contributing to the composite's enhanced mechanical properties.

Conductive, injectable, and self-healing collagen-hyaluronic acid hydrogels loaded with bacterial cellulose and gold nanoparticles for heart tissue engineering

The increasing demand for advanced biomaterials in nerve tissue engineering presents numerous challenges due to the complexity of nerve tissues and the need for materials that can accurately replicate their intricate structure and function. In response, this study introduces a novel injectable hydrogel that is thermosensitive, self-healing, and conductive, offering promising potential for heart and nerve tissue engineering applications. The hydrogel is based on collagen and hyaluronic acid functionalized with 3-aminopropyl-triethoxysilane (APTES)-grafted oxidized bacterial cellulose and gold nanoparticles (~50 nm). Rheological analysis reveals a substantial enhancement in the elastic modulus of the collagen-hyaluronic acid matrix with the incorporation of bacterial cellulose/gold nanoparticles, improving by an order of magnitude at 1 % strain. This improvement comes with a slight decrease in gelation temperature, from 36 °C to 32 °C. Besides thermo-sensitivity, the nanocomposite hydrogel exhibits a remarkable self-sealing response (about 80 % effectiveness) due to reversible physical crosslinking. Electrical spatial resistance measurements on human embryonic stem cell-derived cardiomyocytes-loaded hydrogels yield a value of ~0.1 S/m, which is suitable for electrical stimulation. In vitro extracellular field potential measurements also affirm the hydrogel's potential as an injectable scaffold for heart tissue engineering, i.e., the electrically stimulated human stem cells exhibit 47 beats per minute with a cell discharge (depletion) of 5.47 μv. A rapid gel formation in the physiological temperature (about 2 min) and high H9C2 cytotoxicity (viability of >90 % after 72 h incubation) is attainable. The developed collagen-based nanocomposite hydrogel offers an injectable, thermosensitive, and self-healing biomaterial platform for nerve or myocardium regeneration.

Creating ultra-strong and recyclable green plastics from marine-sourced alginate-chitosan nanowhisker nanocomposites for controlled release urea fertilizer

In response to the pressing environmental challenge posed by petroleum-derived plastics, the development of green plastics derived from all-biomass nanocomposites offers promising solutions. However, conventional nanocomposites often prioritize enhanced stiffness at the expense of flexibility. We introduce sodium alginate (SA)/chitosan nanowhisker (CSW) nanocomposites, derived entirely from marine-sourced all-biomass, to create ultra-strong and flexible green plastics. Through the synergistic interaction between SA and CSW, these nanocomposites demonstrate simultaneous stiffening and toughening, overcoming the traditional trade-off. Two key mechanisms contribute: geometric reinforcement from the needle-like structure of CSW and electrostatic reinforcement at the interface between oppositely charged CSW and SA. Compared to control SA, the SA/CSW nanocomposites exhibit remarkable enhancements in tensile modulus, strength, and stretchability, by 49%, 85%, and 55%, respectively (7.6 GPa, 223.3 MPa, 14.7%). Cellulose nanocrystals, serving as a control, only stiffen the nanocomposites, adhering to the typical trade-off. Biodegradability in compost can be tailored based on the type of nanofillers. Due to the water resistance of CSW, SA/CSW nanocomposites are proven effective for the controlled release of urea fertilizer in agricultural applications. With recyclability and superior mechanical properties, these marine-sourced green plastics offer a sustainable alternative to conventional plastics, promising significant impact in the eco-plastic industry.

Fabrication of Hybrid Epoxy Composites (Joint Compound Adhesive) for Aluminum Substrate Applications and Their Evaluation for Mechanical Properties.

This research endeavor deals with the development of an epoxy hybrid nanocomposite using aliphatic diglycidyl ether of a bisphenol A (DGEBA) epoxy matrix. The formulation used the stoichiometric ratio of the curing agent and incorporated nanopigments such as zirconium and silica, along with other microfillers. We incorporated Zr and SiO2 nanoparticles and various other additives in the epoxy matrix and ensured homogeneous dispersion by using sonication methodology along with silane as a coupling agent. Aluminum molds were utilized to fabricate dumbbell-shaped ASTM standard samples for the testing of mechanical properties. The adhesive properties were evaluated through standard lap shear tests. Fourier transform infrared spectroscopy was utilized to analyze the cross-linking reaction of the epoxy moiety and the polyamidoamine adduct curing agent. Further characterization using field emission scanning electron microscopy, energy-dispersive spectroscopy, and high-resolution transmission electron microscopy confirmed the presence and uniform dispersion of the fillers and nanopigments. The results showed good enhancements in ultimate tensile strength, yield strength, and elastic modulus of 95.3, 162.1, and 425.4%, respectively, compared to formulations using only SiO2. The addition of ZrO2 and SiO2, along with various microfillers, such as talc and aluminum silicate, led to significant improvements in the mechanical properties. This study demonstrates the synergistic efficiency of combining SiO2 and ZrO2 along with microfillers, such as talc and aluminum silicate, in epoxy resin for diverse applications in the construction industry, where mechanical strength and substrate adhesion are crucial.