Incorporation Of Fibers Research Articles

Nylon 66 short fiber reinforcement in EPDM power transmission belting: A path to enhanced mechanical performance

AbstractV‐belts are commonly used to transmit power between two distant pulleys. Therefore, a strong reinforcement for dimensional stability and thermomechanical properties are essential in power transmission belts. The influence of resorcinol formaldehyde resin (RFL) treated nylon short fibers in EPDM peroxide‐cured formulations was investigated, with concentrations ranging from 0 to 30 parts per hundred rubber (phr) in increments of five. The incorporation of nylon short fibers resulted in improved tensile and mechanical properties in EPDM vulcanizates. Specifically, the tensile stress at 100% elongation increased by 177% to (10.8 MPa), and the improvement in tear strength to 16.2% (75.7 N/mm) was observed. Among other functional requirements in a weak rubber like EPDM, enhanced tear strength is significant for its application in power transmission. Substantial reinforcement between the fiber‐elastomer matrix was confirmed via scanning electron microscopy, as evidenced by increased storage modulus (E′). Notably, there were no considerable effects on the curing rate or low‐temperature properties. Significant improvement in heat stability is observed through thermogravimetric analysis. These enhancements in mechanical and thermal properties might play a role in increased durability and performance in actual V‐ribbed belt applications.Highlights This manuscript describes the effect of treated nylon 66 short fiber on EPDM V‐belt compound. A significant increase in storage modulus, tear strength, and thermal stability. A belt is made using the experimental formulation and it meets the performance requirement. Low fiber content (<15 phr) compounds are unsuitable for dimensional stability. High fiber content (>25 phr) compounds pose processing challenges.

Electrothermally controlled origami fabricated by 4D printing of continuous fiber-reinforced composites

Active origami capable of precise deployment control, enabling on-demand modulation of its properties, is highly desirable in multi-scenario and multi-task applications. While 4D printing with shape memory composites holds great promise to realize such active origami, it still faces challenges such as low load-bearing capacity and limited transformable states. Here, we report a fabrication-design-actuation method of precisely controlled electrothermal origami with excellent mechanical performance and spatiotemporal controllability, utilizing 4D printing of continuous fiber-reinforced composites. The incorporation of continuous carbon fibers empowers electrothermal origami with a controllable actuation process via Joule heating, increased actuation force through improved heat conduction, and enhanced mechanical properties as a result of reinforcement. By modeling the multi-physical and highly nonlinear deploying process, we attain precise control over the active origami, allowing it to be reconfigured and locked into any desired configuration by manipulating activation parameters. Furthermore, we showcase the versatility of electrothermal origami by constructing reconfigurable robots, customizable architected materials, and programmable wings, which broadens the practical engineering applications of origami.

High-Pressure Processing of Fruit Smoothies Enriched with Dietary Fiber from Carrot Discards: Effects on the Contents and Bioaccessibilities of Carotenoids and Vitamin E.

The effects of high-pressure processing (HPP) (450 MPa/600 MPa/3 min) on the carotenoid and vitamin E contents of smoothies made from strawberry, orange juice, banana and apple, and the same smoothies enriched with dietary fiber from discarded carrots were compared. The contents and bioaccessibilities of these compounds were also evaluated over the course of 28 days at 4 °C. The application of HPP in the formulations significantly increased the contents of β-cryptoxanthin, α-carotene and β-carotene and retained the contents of lutein, zeaxanthin and vitamin E compared to untreated samples. A decreasing trend in the content of each compound was observed with an increase in storage time. The application of HPP initially led to reductions in the bioaccessibility of individual compounds. However, overall, during storage, there was an increase in bioaccessibility. This suggests that HPP influences cell structure, favoring compound release and micelle formation. HPP is a sustainable method that preserves or enhances carotenoid extractability in ready-to-drink fruit beverages. Furthermore, the incorporation of dietary fiber from carrot processing discards supports circular economy practices and enhances the health potential of the product.

Impact of treated red-algae fibers on physico-mechanical behavior of compressed earth bricks for construction

Red algae, abundant along the Moroccan coast, have fostered an agar-agar industry. However, industrial processing of red algae produces significant fibrous waste, posing environmental challenges. A new challenge is to find sustainable methods for repurposing this fibrous waste. Valorizing red-algae fibers in building materials promotes sustainable development and eco-construction. This study aims to valorize these red-algae residues as fiber reinforcements in compressed earth bricks (CEB). Various mass ratios of red-algae fibers (0.5%–3%) were incorporated into CEB. The addition of raw red-algae fibers to mixtures slightly increased the Atterberg limit values of the earth mixture. A slight adjustment in manufacturing water content was also observed with fiber addition. The incorporation of red-algae fibers did not improve the mechanical strengths of the CEB. Nevertheless, at a 1.5% addition ratio, CEB exhibited compressive and flexural strengths of 4.07 and 0.77 MPa respectively. To enhance mechanical properties, fibers were pre-saturated and subjected to alkaline and double coating treatments. Untreated and treated fibers were added to CEB at an optimal mass addition rate of 1.5%. Pre-saturated fibers showed a slight improvement of 5% in mechanical strength. However, alkali-treated and double-coated fibers offer a significant improvement of 20% in the mechanical strengths of CEB, demonstrating the efficacy of treatments.

An investigation of the microstructure and tribological behavior of polyether ether ketone composites fabricated by extrusion‐based additive manufacturing

AbstractCarbon fiber reinforced polyether ether ketone (CF/PEEK) composites are widely used as tribo‐materials in the aerospace and automotive industry. To amplify the industrial utilization of extrusion‐based additive manufacturing fused deposition modeling in fabricating CF/PEEK tribo‐composites, the composites' microstructure–property relationship was studied with respect to carbon fiber content varying between 5 wt% and 30 wt%. This revealed that the incorporation of carbon fibers helped enhance the mechanical strength of PEEK greatly with an optimal content of 5 wt%, at which the composite material exhibited the highest crystallinity as well as the best mechanical performance. Tribological tests indicated that CF/PEEK composites were more suitable for high speed and heavy load conditions especially for 20 wt% CF/PEEK, which was associated with the establishment of high quality transfer films covered on counter steel surfaces. The present work provides a simple and low cost way of fabricating high performance PEEK composites used as tribo‐materials. © 2024 Society of Industrial Chemistry.

Numerical Analysis of Rubberized Steel Fiber Reinforced Concrete Beams Subjected to Static and Blast Loadings

In recent years, the alarming number of terrorist attacks has highlighted the critical need for extensive research aimed at fortifying structures against explosion-induced loads. However, the insufficient energy absorption and brittleness of conventional concrete make it ineffective in withstanding blast loading, encouraging researchers to explore innovative strategies for augmenting the energy dissipation capabilities of construction materials. This study specifically delves into the incorporation of recycled rubber, a sustainable and environmentally friendly solution to the pressing issue of scrap tire disposal. The primary focus of this research revolves around the integration of rubber recycling and steel fibers into concrete, with the ultimate goal of enhancing the dynamic response of reinforced concrete (RC) beams. This novel approach not only contributes to the structural resilience required for resisting blast impacts, but also aligns with eco-friendly practices by reusing recycled rubber. A meticulous numerical investigation was undertaken to comprehensively assess the static and blast response of these augmented beams. The numerical study involved developing finite element (FE) models using ABAQUS version 6.14 for static implicit analysis and LS-DYNA R11 for blast explicit simulations. The ABAQUS model was validated against previous experimental testing for load–displacement and failure patterns. Similarly, the LS-DYNA model was validated for blast pressure in accordance with UFC-3-340 standards and for material response under blast loading, utilizing existing experimental data. The numerical models were designed to accommodate varying weight percentages of rubber, ranging from 5% to 20%, and a consistent 1.0% incorporation of steel fibers. This comprehensive analysis aims to provide valuable insights into the efficacy of these materials in improving the structural integrity and blast resistance of RC beams, thereby contributing to the development of more secure and sustainable construction practices. By reducing the reinforcement ratio in order to meet the minimum code requirements, it became evident that the failures of the rubberized RC beams tended to exhibit ductility on the tension side under static loading. In addition, the increase in the reinforcement ratio correlated with a higher failure load and decreased deflection. Furthermore, the findings indicated an optimal concrete mixture characterized by improved ductility, energy absorption, and blast load capacity, achieved by combining 5–10% rubber with steel fibers.

Strength Performance of Concrete Containing Rice Husk Ash as Cement Replacement in Presence of Polypropylene Fiber

This study focuses on the utilization of Rice Husk Ash (RHA) as partial replacement of Ordinary Portland Cement (OPC) in concrete in addition with Polypropylene (PP) fiber. The main goal of this study was to decrease dependence on OPC and address environmental waste generated through rice mills. This study considered concrete cubes prepared through 1:2:4 ration with 0.50 water-cement ratio with and without RHA and PP fibers. The water curing was done for 7 and 28 days, with three specimens for each proportion, and the average value was considered as the result. It was observed that the compressive strength of M2 concrete which containing 10% RHA was noticed 7% higher than the control mix concrete and declared as 10% RHA as optimum dosage. Next, the performance in terms of compressive strength of concrete containing optimum dosage of RHA in presence of PP fibers of three different lengths were also evaluated and found that the 0.1% of PP fiber of 0.5 inches length gives the 25% higher strength performance as compared to the control mix and 17% higher than the concrete containing 10% RHA only at the age of 28days. Hence, this study concluded that the replacing OPC cement with 10% RHA produces satisfactory strength performance and incorporation of PP fiber gives better strength performances.

Closed-form fracture model for evaluating crack resistance of 3D printed fiber-reinforced alkali-activated slag/fly ash recycled sand concrete

To reduce resource consumption and greenhouse gas emissions, 3D printed alkali-activated slag/fly ash recycled sand (RS) concrete (3DP AARSC) was developed in this paper. The reasonable evaluation of its crack resistance is crucial to structural safety and stability since steel bars are still difficult to embed in 3DP samples automatically so far. The realistic fracture parameters can be responsible for the reasonable evaluation and are extremely difficult to predict accurately based on traditional methods unless the specimen sizes are large enough. Therefore, the purpose of this study is to determine the size-independent tensile strength (ft) and fracture toughness (KIC) through a predictive fracture model incorporating the heterogeneity and discontinuity of 3DP AARSC. First, fracture tests of small-sized specimens were conducted to clarify the fracture mechanisms of 3DP AARSC in different loading directions. Subsequently, based on the boundary effect model, the size-independent ft and KIC were explicitly correlated to the maximum fracture load (Fmax) in different loading directions and directly obtained if Fmax was measured from the tests. The results displayed that the predicted ft and KIC of 3DP AARSC loaded perpendicular to the printing direction were significantly higher than the counterparts of concrete loaded parallel to the printing direction by 108.7% at most. The greatest cracking resistance was demonstrated in the specimens with the RS replacement rate of 60% for natural river sand (NS), resulting in the maximum increase of 19.9% in ft and KIC compared with the 3DP concrete with 100% NS. The fiber addition and partial RS replacement increased the difference in the crack resistance along various loading directions. Moreover, the fiber incorporation had no significant improvement in the crack resistance of 3DP AARSC loaded parallel to the printing direction and apparently increased its ft and KIC along other loading directions.

Effect of hemp fibers and crystalline admixtures on the properties and self-healing efficiency of lime and clay-based mortars

This study investigates the impact of hemp fibers on two fiber-reinforced compositions, clay-based and lime-pozzolan mortar. Three compositions were prepared for each mortar, reference samples without fiber incorporation, samples with untreated hemp fibers, and samples with hydrothermally treated hemp fibers with crystallines. Crystalline admixtures (CAs) were incorporated into the hydrothermal pretreatment of fibers to promote the self-healing properties of the mortar when needed. Physico-mechanical and thermal properties took place to address the overall effect of hemp on the mortars. Adding hemp fibers enhanced the mechanical strength and reduced the mortars' shrinkage. The hydrothermally treated fibers have better cohesion with mortars, preserving the best results. To evaluate self-healing efficiency, pre-damaged cubic samples from each composition were subjected to tap water immersion for lime-pozzolan mortars and a controlled humid chamber for clay mortars after a curing period. The healing rate was assessed by measuring crack closure, compressive strength recovery, and the dynamic modulus of elasticity recovery. The results indicated significant strength recovery in lime-pozzolan mortars with hemp fibers. Clay-based mortars showed moderate strength increases and limited self-healing.

Recent progress in shape memory alloy reinforced composites: A review of the properties, production, mechanisms involved and functional applications

SMAs are unique materials characterized by their 'Superelasticity' (pseudoelasticity) and 'Shape Memory Effect.' Its unusual properties have led to its use in various fields of science. However, its mechanical advantages are not fully exploited due to its price and lack of data. SMAs are not adopted widely in industries due to the scarcity of manufacturing knowledge. Potential uses for them came in the form of reinforcements in composites. The rapidly growing field focuses on the incorporation of Shape Memory Alloy wires, ribbons, fibres, and powders in polymer or metal matrices. Its effect on static and dynamic material properties is also of great importance, especially when it comes to incorporating it into modern-day applications. Hence, this paper deals with a summary of all those properties. Furthermore, the article touches upon the possible applications of Shape Memory Alloy Reinforced Composites in the real world and their potential scope in the future.

Composite materials using recycled high-density polyethylene plastic for railway sleepers

Given the substantial increase in railway load, speed and traffic, there is a notable demand for materials with high durability, long life and good damping. Such materials can be realized through composite materials that contain recycled high-density polyethylene, polypropylene (PP), mica, glass fiber and compatibilizers. In this study, extruded pellets containing the aforementioned materials and produced using a twin-screw extruder were utilized to assess their mechanical performances and microstructures. Composite materials containing 62.5% glass fiber and 20% PP demonstrated remarkable performance for manufacturing sleepers. The addition of 62.5% glass fiber in composite materials containing PP enhanced the flexural strength, flexural modulus, tensile strength and compressive strength by 315, 623, 296 and 40%, respectively, as compared with those of the original composite materials containing PP without glass fiber. Furthermore, the incorporation of glass fiber and the subsequent improvements met the requirements stipulated by the Ministry of Housing and Urban–Rural Development of the People’s Republic of China and International Organization for Standardization standards. This favorable result can be attributed to the good compatibility between the matrix and the glass fiber, as noted from the uniform distribution of glass fiber in the resin matrix in scanning electron microscopy images. The findings of this study highlight the potential of utilizing recycled materials in rail-track-manufacturing applications.

Effective Utilization of Bio and Industry Wastes to Produce Thermal Insulation Concrete: A Novel Solution for Energy-Saving Buildings

The research addressed the effective and sustainable ways to enhance the thermal insulation properties of concrete without compromising its structural integrity. Traditional methods of enhancing thermal insulation in buildings, such as using thick layers of insulation materials, can be costly and may not always be practical in certain settings. Additionally, the disposal of waste materials such as date palm fiber, shopping plastic bags, and thermocol beads presents an environmental challenge. Therefore, this study aims to investigate the potential use of these waste materials as additives in concrete to improve its thermal insulation properties while also providing a sustainable solution for waste disposal. Date palm fiber is a natural material that is widely available in the Gulf region. Plastic bags are a huge waste from the shops every day, and from the packing materials, this thermocol is a huge waste product. We have to recycle it very efficiently to protect the environment. Three types of special materials, such as thermocol beads (30%), date palm fiber (3%) & shopping plastic bag fiber (3%), were tested in this research. Thermocol beads, when used, reduce their strength and increase the thermal resistance of concrete, while date palm fiber and shopping bag waste fiber, when used, increase the strength of concrete and also increase the thermal resistance of concrete, so it is an excellent reinforcing material and thermal barrier for shopping plastic bags fiber and date palm fiber. Based on this research result, when thermocol beads are used, they prevent heat by 42 percent, while when added with date palm fiber and plastic fiber, they also block heat by an average of 30% percent; thus, all three ingredients are considered excellent thermal insulation material. The reduction in thermal conductivity was attributed to the formation of air voids and the low thermal conductivity of the waste materials. The density of the concrete decreased with the addition of the waste materials. The study suggests that the incorporation of date palm fiber, shopping bag waste fiber, and thermocol beads can be an effective way to enhance the thermal insulation properties of concrete while also providing an environmentally sustainable solution for waste disposal. It will boost green energy technology in the construction industry.

Chloride diffusion behaviour and structural performance of basalt fiber- reinforced concrete beam in marine environment

For marine reinforced concrete structures exposed to saline water, the rate of penetration of chloride ions into concrete is crucial to their performance. To resist the chloride penetration within marine structures, the incorporation of basalt fibers into M40-grade concrete was pursued. The current research develops into two primary investigations. The first pertains to the determination of chloride penetration depths and the associated diffusion coefficients of concrete cubes, while the second focuses on the structural behaviour of basalt fiber-reinforced concrete beams under chloride diffusion. The chloride diffusion coefficients were determined using experimental methods for eight concrete cubes with varying proportions of basalt fiber (0%, 0.5%, 0.75%, and 1% v/v). These coefficients were subsequently validated through numerical methods, applying Fick’s law. Additionally, numerical techniques were employed to calculate chloride concentration and the corresponding flux at various diffusivity time intervals, leading to the development of corresponding chloride concentration equations. A corelation was developed in between chloride penetration depth, time period and dose of basalt fiber. The present model can be used as a tool for analysis to represent the real condition of concrete deterioration brought on by chloride action. In terms of examining structural responses, a comprehensive evaluation was conducted encompassing load deflection behaviors, crack propagation tendencies, and stress-strain analyses of concrete beams reinforced with basalt fibers. The stress block diagram had been modified by determining various stress block parameters (αandβ) of chloride diffused basalt fiber reinforced concrete beam under cyclic load.

CEMENT MORTARS WITH BOMBYX MORI SILK FIBERS WITH DIFFERENT TYPES OF SURFACE TREATMENTS

The incorporation of natural fibers in cement mortars is an important area of research and development within the construction industry, as it seeks sustainable and ecological alternatives to traditional fiber reinforcements. This paper investigated the effects of different treatments on “Bombyx mori” silk fibers on the mechanical strength and durability of cement mortars, at the same time their architectural possibilities were analyzed. The studied fibers were cut to 20 mm in length, then treated with liquid calcium hydroxide, linseed oil and natural rubber latex. Finally, they were placed in the cement matrix in layers and arranged lengthwise. The mechanical performance and durability of the material were studied through the physical properties of water absorption by immersion, the mechanical properties of compressive, flexural, and impact strength at 7, 14, and 28 days of curing were also studied. The study was complemented with a simulation of alkaline environment of cement using a solution based on sodium hydroxide, measuring the degree of accelerated degradability of the fibers through mass loss. Overall, the results demonstrated that the composite material with fibers treated with natural latex and linseed oil exhibited higher flexural, compressive and impact strength and lower water absorption.

Modeling the Stimulus-Responsive Behaviors of Fiber-Reinforced Soft Materials

Hydrogels can change their size upon swelling. The swelling ratio is the same for all directions in the stress-free state. Dielectric elastomers can reduce their thickness and expand the area upon an electric field. Similarly, the expansion ratio in the plane is also the same for different directions. This isotropic shape change effect limits the function of these soft materials in certain circumstances. To address this issue, recent works have shown that the incorporation of fibers into the polymer matrix can induce an anisotropic response upon external stimulus. In this work, we develop multi-field coupling models for both fiber-reinforced hydrogels and dielectric elastomers. For the former, the change in free energy is caused by the stretching of polymer chains and fibers and the mixing of solvents and polymer networks. The Fickian-type law is adopted for the solvent diffusion. The free energy density for the latter consists of a mechanical part, considering the deformation of both polymer matrix and fibers, and an electric polarization component. Gauss’s law is adopted to obtain the distribution of the electric field. The multi-field models are then implemented for finite element analysis. We consider the stimulus-responsiveness of bilayer strips with an active layer and a passive layer. Without fibers, the strips bend upon the external stimulus. In contrast, the shape changes to helix shapes, which can be further tuned by changing the distribution of fibers. The work provides an efficient design tool for self-folding structures based on stimulus-responsive polymers.

Research on mechanical properties of concrete by nano-TiC-BF-fly ash.

Ultra-high-rise buildings require high concrete bearing capacity. Ordinary concrete often fails to meet the project requirements. Admixture of admixtures in concrete is a means of solution. Currently, studies on the incorporation of basalt fiber (BF) and fly ash (FA) in concrete are relatively mature. However, research on incorporating nano-Titanium Carbide (nano-TiC) in concrete is still relatively scarce, which has a lot of room for development. To further improve the mechanical properties of concrete, BF, and FA synergized with nano-TiC were incorporated into concrete to produce TBF concrete in this study. And Response Surface Methodology (RSM) was used to optimize the mechanical properties of concrete. The collapse and compressive deformation damage characteristics of concrete were analyzed. The microstructure of the cement matrix was analyzed by the SEM (Scanning Electron Microscope). An optimization model of the TBF concrete craving function was developed. Optimized ratios with compressive, split tensile, and flexural strengths as response objectives were obtained, and the accuracy of the optimized ratios was investigated using the same experimental conditions. The results of the study showed that FA increased the collapse of concrete, while nano-TiC and BF decreased the collapse of concrete. Under uniaxial compression, nano-TiC, FA, and BF together incorporated into concrete can improve its compressive damage state. Moderate amounts of nano-TiC, BF, and FA could improve the mechanical properties of concrete. Their optimal mixing ratio admixtures were 0.88%, 0.24%, and 5.49%, respectively. And the measured values under the same conditions were compared with the predicted values. The maximum difference in compressive strength was 6.09%. The maximum difference in split tensile strength was 7.14%. The maximum difference in flexural strength was 8.45%. This indicated that the accuracy of the RSM optimization model was good. A moderate amount of nano-TiC, FA, and BF could improve the densification of concrete.

Effect of plant short fibers on the mechanical properties of carbon fiber reinforced epoxy matrix by using FEM based numerical homogenization technique

In this study, we utilized the material design library in Ansys Product 2022 R1 to analyze the impact of short plant fibers on the mechanical properties of epoxy resin. We employed the representative volume element (RVE) approach and examined different volume fractions up to 50%. The technique employed in this study was multi-scale modeling based on the finite element method (FEM) for numerical homogenization. Subsequently, we used the same software to develop a five-layer laminated composite. The samples were based on epoxy resin enriched with short plant fibers at fractions of 20% and 30%, as well as pure epoxy resin. The laminated composites were reinforced with carbon fibers. The objective of this study was to analyze the mechanical response of each sample during a tensile test, focusing on multiple parameters. The sought-after results included total deformation, directional deformation, equivalent and elastic stress (Von-mises). The samples containing epoxy resin enriched with 30% of short hemp fibers exhibited remarkable mechanical strength compared to the other samples. These results suggest that the incorporation of short hemp fibers into the matrix led to a significant improvement in the mechanical strength of the composite.

Experimental Study of Innovative FRC Dome-Shaped Structures with Industrial, Recycled, and Alternative Reinforcing under Compressive Load

Arc concrete structures are aesthetic and suitable for buildings with large spans. Within the framework of this research, fiber-reinforced concrete (FRC) dome-shaped structures were studied in a lab, analyzing mechanical performance via strength, deformation, and failure mode. The studied FRC was elaborated with industrial, recycled, and alternative fibers. The mold used for producing the dome specimens was made up of two parts in order to favor extraction. This study considered 21 dome samples reinforced with fibers and one control, with replication for those with atypical behavior. The results show that the load-displacement behavior of dome-shaped elements increases with the incorporation of fibers, which depends on the fiber dose and the material. Moreover, the efficiency analysis proved that specimens with low fiber content (20 and 2 kg/m3) have the best strength-reinforcement relation. The recycled and alternative fibers exhibit good mechanical performance and ductility. The main contribution of this research is a study of the scope and limitations of different types of FRC as the only reinforcement in arched structures.

Ultrathin SiO2 aerogel papers with hierarchical scale enable high-temperature thermal insulation

Aerogel composites reinforced by fibers have found extensive applications in the field of thermal insulation and energy conservation. However, the composites are hindered by their high infrared radiation transmittance and weak interface adhesion in practical applications. Herein, we designed and prepared a novel thin composite called ‘fiber/whisker/aerogel paper’ (SWAP) with a thickness of less than 1 mm. The SWAP integrated SiC nanowhiskers (SiCnw) as opacifiers and ultrafine SiO2 fibers as reinforcement, fabricated through wet manufacturing and sol-gel process. The ‘fiber/aerogel paper’ (SAP) and SWAP exhibited low thermal conductivity at room temperature, measuring 0.025 W/(m·K) and 0.033 W/(m·K), respectively. Additionally, they exhibited low densities of 0.195 g/cm3 and 0.225 g/cm3, respectively. Notably, SWAP exhibited excellent high-temperature insulation performance, primarily due to its low infrared transmittance (50% at 3 μm). The incorporation of SiCnw and ultrafine SiO2 fibers collectively enhanced the interfacial adhesion with the aerogel matrix even amidst rigorous testing (weight loss less than 3%). SWAP also demonstrated flexibility, high thermal stability, hydrophobicity, and flame resistance. Furthermore, a comprehensive investigation into the performance variations and influencing g factors of the material was conducted under different heat treatment conditions. This research provides guidance for the application of such materials under high temperatures.

Alkaline pretreatment and steam explosion process on coffee silverskin and incorporation of cellulose fibers in poly(butylene adipate‐co‐terephthalate)

AbstractIn this work, coffee silverskin (CSS) fibers were subjected to alkali pretreatment (ALK‐CSS) and alkali pretreatment, followed by a 4‐bar steam explosion process (SEW4). Both treated fibers presented a higher degree of crystallinity, enhanced thermal resistance and also cleaner, rough, and defibrillated surface due to the removal of noncellulosic components, as was shown in scanning electron microscopy, thermogravimetric analysis, Fourier‐transform infrared spectra, and x‐ray diffraction (XRD) results. The SEW4 fibers were incorporated into the poly(butylene adipate‐co‐terephthalate) (PBAT) matrix in contents up to 5% wt. through melt processing. PBAT/SEW4 composites were evaluated by their microstructure, thermal properties, degree of crystallinity, and hydrophilic behavior. XRD results showed PBAT/SEW4 composites with higher degrees of crystallinity and contact angle tests revealed increased composite hydrophobicity with the increase of SEW4 content in the PBAT matrix. This work describes the importance of recovering coffee lignocellulosic waste and producing value‐added by‐products, especially in packaging manufacturing.