Filled Polymer Composites Research Articles

Delamination of MXene using biomolecule: An effective strategy toward the utilization of delaminated MXene as fillers in polymer composites

AbstractWith the emergence of two‐dimensional (2D) materials analogous to graphene, transition metal carbides and carbonitrides with unique desirable characteristics known as MXenes have turned out to be a hot research topic. Recent studies increasingly focus on the structure–property relationships of MXenes and their hybrid formations with other materials. The exfoliation and delamination of MXenes using various agents is gaining attention, while their application in functional composites presents another exciting research direction. However, the exfoliation of multi‐layered MXene into few‐layered nanosheets using bio‐based agents remains underexplored. In this study, tannic acid (TA) is employed as a bio‐exfoliating agent to delaminate Ti3C2Tx MXene, while optimizing the ratio of TA to achieve efficient exfoliation and dye adsorption. The MXene/TA composites demonstrated a maximum adsorption capacity of 187.264 mg/g and a removal efficiency of 93.69% for methylene blue (MB) in water, in accordance with the Langmuir isotherm model. Furthermore, MB adsorption caused MXene to coagulate into floccules, enabling easy removal via filtration. The study highlights the trifold role of tannic acid in MXene as a delaminating, antimicrobial, and adsorption‐enhancing agent, creating a multifunctional MXene‐tannic acid system. It introduces a new class of hybrid materials with effective applications in water purification. Additionally, incorporating this hybrid material into polymers can fine‐tune their properties, leveraging the synergistic effects of the trio to develop high‐performance smart polymer composites for diverse applications.Highlights Synthesis of MXene from Ti3C2Tx Optimization of the delamination efficiency of the biomolecule tannic acid Characterization of tannic acid‐MXene delaminated composites Analysis of the antibacterial efficiency of tannic acid delaminated MXene Investigation of water purification efficiency of delaminated MXene

Bioinspired surface modification of mussel shells and their application as a biogenic filler in polypropylene composites

This study explores the potential of mussel shells (MS) as biogenic fillers in polymer composites. The chemical composition and crystal structures of MS were characterised. To improve MS filler dispersion and adhesion within a polypropylene (PP) matrix, three surface modification methods were evaluated: polydopamine (PDA) coating, maleic anhydride-grafted polypropylene (MAPP) modification, and PDA/MAPP co-modification. The PDA coating, inspired by the adhesive properties of mussel foot proteins, successfully functionalized the MS surface, as confirmed by X-ray photoelectron spectroscopy (XPS). Thermodynamic analysis, based on contact angle measurements, revealed that MAPP and PDA/MAPP modifications reduced surface energies and potential energy differences. These changes enhanced filler dispersion and interfacial bonding by increasing hydrophobicity and reducing agglomeration in the PP matrix. Consequently, PP composites with 20% PDA/MAPP-modified MS fillers exhibited a 2.9% increase in tensile strength and a 7.5% increase in flexural strength compared to neat PP. Scanning electron microscopy (SEM) also showed reduced filler-matrix debonding and fewer voids. The proposed mechanism attributes these macroscopic property enhancements to the ability of the PDA coating to facilitate chemical and hydrogen bonding between MS fillers and MAPP.

OPTIMAL PROPERTIES OF SURFACE MODIFIED CELLULOSE AS FILLER IN POLYMER COMPOSITES

The research and development of new materials that are not only functional, but also ecologically acceptable, is a key aspect in many branches of industry. Such materials include elastomeric composites reinforced with alternative fillers such as cellulose. Cellulose is a renewable and biodegradable alternative to traditional fillers used in elastomeric composites. The main disadvantage of this biopolymer is its poor compatibility with the hydrophobic matrix and low mechanical strength. The free hydroxyl groups on the cellulose surface allow for a wide range of surface modifications. In this work, we focused on the chemical modification of cellulose using two different silanes due to their ability to react with the free hydroxyl groups on the surface of cellulose. This work deals with the characterisation of thermal stability of surface modified cellulose used as filler in polymer composites. Cellulose modified in this way was used in the amount of 45 phr as a filler in the preparation of elastomeric composites with natural rubber (NR) matrix. The NR composite filled with surface modified cellulose was characterized by TG/DSC, IR spectroscopy, XRD and scanning electron microscopy.

Green hybrid materials from biomass waste: Distiller’s grains/epoxy vitrimer—Green synthesis, superior properties, and potential application in solar-thermal-electric generator

Distiller’s grains (DG) are a major biomass waste product in the ethanol and brewing industries, and have shown great potential as fillers for polymer composites. However, combining DG with polymer matrixes using traditional method often involves tedious pre-modification of DG and/or the use of costly coupling agents, significantly increasing the preparation cost of the final composite materials. In this study, we present an environmentally friendly approach for preparing a new type of green composite, termed distiller’s grains/epoxy vitrimer hybrid materials (EV@DG). This method eliminates the need for laborious pre-modifications of DG, as well as the use of solvents and coupling agents. The resulting EV@DG hybrid materials exhibit superior mechanical properties—approximately 90 % increase in tensile strength and 400 % increase in Young’s modulus—along with high thermal stability (Td,max of 357.63°C) and excellent reprocessability. Moreover, the EV@DGs demonstrate impressive photothermal conversion capabilities, positioning them as promising candidates for the fabrication of solar-thermal-electric generator.

The interface dewetting process of particulate filled polymer composite

AbstractDewetting is one of the most common damage modes in particulate filled polymer composite, which greatly damages the structural integrity of the composite and leads to the deterioration of its mechanical properties. Studying the dewetting evolution process of composite is of great significance for evaluating the meso damage degree of composite and suppressing the development of dewetting damage. This article constructs an axisymmetric cylindrical cell model of a single particle inclusion matrix, derives the interface dewetting evolution process of the model under uniaxial tensile loading condition, and analyzes the influence of model geometric parameters and external loading conditions on the dewetting process. Subsequently, numerical models were constructed at both micro and meso scales, and dynamic tensile calculations were performed to analyze the correlation between the dewetting rate, porosity, and mechanical performance. Finally, a cylindrical cell specimen was designed to observe the interface dewetting evolution under uniaxial tensile conditions, confirming the conclusions of theoretical analysis and numerical simulation.Highlights Constructed a theoretical model for the dewetting process of interface. Conducted numerical analysis of dewetting process at both meso and micro scales. Designed interface dewetting experiment and analyzed the dewetting process.

Synthesis of bio-polyol-functionalized nanocrystalline celluloses as reactive/reinforcing components in bio-based polyurethane foams by homogeneous environment modification

Nanocrystalline Cellulose (NCC or CNC) is widely used as a filler in polymer composites due to its high specific strength, tensile modulus, aspect ratio, and sustainability.However, CNC hydrophilicity complicates its dispersion in hydrophobic polymeric matrices giving rise to aggregate structures and thus compromising its reinforcing action. CNC functionalization in a homogeneous environment, through silanization with trichloro(butyl)silane as a coupling agent and subsequent grafting with bio-based polyols, is herein investigated aiming to enhance CNC dispersibility improving the filler-matrix interaction between the hydrophobic PU and hydrophilic CNC. The modified CNCs (m_Ci) have been studied by XRD, SEM, and TGA analyses. The TGA results show that the amount of grafted polyol is strongly influenced by both its molar mass and OH number and the maximum amount of grafted polyol reaches up to 0.32 mmol per grams of functionalized CNC, within the explored conditions. The effect of different concentrations (1–3 wt%) of m_Ci on the physical, morphological, and mechanical properties of the resulting bio-based composite polyurethane foams is evaluated. Composite PU foams present compressive modulus up to 4.81 MPa and strength up to 255 kPa more than five times higher than those reinforced with unmodified CNC or with modified CNC in heterogeneous chemical environment. The improvement of mechanical properties of the examined PU foams, as a consequence of the incorporation of bio-polyols modified CNCs where polyol's OH groups interact with polyurethane precursors, could further broaden the use of these materials in building applications.

Effects of spherical fillers reinforcement on the efficacy of thermal conductivity in epoxy and polyester matrices: Experimental validation and prediction using finite element method

AbstractThe creation of a theoretical heat conduction model for polymers embedded with spherical inclusions is described in this study. It also contains the experimental confirmation of the suggested correlation for utilizing the model to estimate the effective thermal conductivity (K) of such composites. According to ASTM‐E‐1530, composites are made with varying amounts of aluminium oxide and pine wood dust reinforced in polyester resin. The effective thermal conductivities (Keff) of the composites are then determined using the Unitherm TM model 2022. Ansys 19.R2 software is used to evaluate the effective thermal conductivity of these composites with a uniform filler distribution, while Digimat‐FE software is used determine the thermal conductivity values of such particle filled polymer composites with a random filler distribution. After comparison and validation with experimental data, these values are shown to be fairly good agreement with the theoretical values from the suggested correlation. The investigation is further expanded to determine the thermal conductivities for epoxy composites using wood apple shell dust and coir dust particle. Also epoxy and polyester composites reinforced with SiO2 and TiO2 have been investigated in the similar manner. The main thrust of this report to validate the numerical results of composites by varying numerous polymers. The thermal conductivity all the composites grow monotonically with increase in filler content. The thermal conductivity of silicon dioxide, titanium oxide, and aluminium oxide filled epoxy composites is measured as 1.5, 7, and 35 W/m‐K respectively.Highlights In this study spherical fillers are successfully used as a potential filler material in polyester composites The thermal conductivity predicted by proposed mathematical model of polyester is validated with measured value and found better agreement. The Ansys 19.R2 and digimat software are used to predict the thermal conductivity values of these composites. The mathematical model is further used to predict thermal conductivity of epoxy composites to check the accuracy of the model.

Advances in the structure and preparation of electromagnetic shielding composites with carbon-based filler polymers

The growth of electronic equipment applications, such as aerospace weaponry, wireless base stations, and 5G communication technologies, has led to serious electromagnetic interference (EMI) and pollution problems. These issues can cause equipment overload and damage. Carbon-based fillers are commonly used as conductive fillers in EMI shielding materials due to their low cost, lightweight and flexible nature, high thermal and electrical conductivity, corrosion resistance, and ease of processing and molding. This paper aims to provide theoretical support for future research by identifying the major trends in the recent advancements of carbon-based filler polymer composites for electromagnetic shielding from the years 2020 to 2024, specifically in filler selection, multifunctional interface design, and preparation methods. Furthermore, this paper discusses the shielding principle of EMI shielding materials, the influence of different kinds of carbon-based fillers on the EMI shielding effect of polymer matrix composites, and the challenges and progress of their preparation methods. In the end, it concludes by proposing future research directions to overcome current technological barriers and further develop EMI shielding materials for industrial applications.

Comparative study of various volcanic materials as fillers in polymer composites

Comparative study of various volcanic materials as fillers in polymer composites

A STATE OF ART AND PROSPECTS OF RED MUD MANAGEMENT

The basic data on the global volumes and composition of red mud, which is a highly alkaline waste of the aluminum industry, namely the Bayer process – technology for the extraction and purification of alumina (aluminum oxide) from bauxite are presented. The analysis of the current state of red mud management allows to distinguish the following main directions: physical-mechanical, physical-chemical, biological and combined methods of handling it, which are used in agriculture (chemical land reclamation (increasing soil pH), use as fertilizers); building materials industry (cement, construction mortar, expanded clay, fireclay, bricks, building blocks, ceramic tiles, concrete alkali-acid-resistant products, refractories); road construction (soil strengthening for the lower layers of the road surface, asphalt); production of other materials (sorbents, catalysts, flocculants, pigments, caustic soda, filler for polymer composites); ferrous and non-ferrous metallurgy. Currently, the most common methods of red mud utilization are its direct use, use in the construction materials industry, as well as pyrometallurgical technologies, as a result of which iron or its alloys are obtained, as well as slag, from which alumina, titanium, rare earth metals can be extracted or which is processed into various building materials. The most expedient method of red mud disposal is either direct use of red mud with minimal changes in its properties, or complex processing with maximum yield of target components and minimization of new waste generation. At the same time, one of the promising ways of red mud management can be its biological processing with the help of plants and microbes, which will help reduce the dangerous man-made load from red mud in the territory adjacent to bauxite processing plants. Bibl. 113, Fig. 2.

Characterization of Syzygium cumini (L.) Skeels (Jamun Seed) Particulate Fillers for Their Potential Use in Polymer Composites.

Syzgium cumini (L.) Skeels powder (S. cumini powder), also known as Jamun, is well-known for its various medical and health benefits. It is especially recognized for its antidiabetic and antioxidant properties. Thus, S. cumini powder is used in various industries, such as the food and cosmetic industries. In this work, the fruit of S. cumini was utilized; its seeds were extracted, dried, and ground into powder. The ground powders were subjected to various techniques such as physicochemical tests, Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), particle size analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and antioxidant analysis. From the physicochemical tests, it was revealed that the jamun seed filler contained cellulose (43.28%), hemicellulose (19.88%), lignin (23.28%), pectin (12.58%), and wax (0.98%). The FTIR analysis supported these results. For instance, a peak at 2889 cm-1 was observed and associated with CH stretching, typically found in methyl and methylene groups, characteristic of cellulose and hemicellulose structures. The XRD results demonstrated that the crystallinity index of the jamun seed filler was 42.63%. The particle analysis indicated that the mean (average) particle size was 25.34 μm. This observation was ensured with SEM results. The EDX spectrum results showed the elemental composition of the fillers. Regarding thermal degradation, the jamun seed filler had the ability to withstand temperatures of up to 316.5 °C. Furthermore, endothermic and exothermic peaks were observed at 305 °C and 400 °C, respectively. Furthermore, the antioxidant property of the powder displayed a peak scavenging activity of 91.4%. This comprehensive study not only underscores the viability of S. cumini powder as a sustainable and effective particulate filler in polymer composites but also demonstrates its potential to enhance the mechanical properties of composites, thereby offering significant implications for the development of eco-friendly materials in various industrial applications.

Nanocarbon‐Based Hybrid Fillers in Thermally Conductive Polymer Composites: A Review

With the broad commercialization of microelectronics, 5G communication, and new energy vehicles, the demand for polymer composites with high thermal conductivity (TC) increases. Carbon‐based nanomaterials have high TC, are of lightweight and low cost, and have been widely studied as thermally conductive fillers for composites. In this article, carbon‐based thermal conductive fillers in polymer composites are focused on. It summarizes the treatments of functionalization, directional arrangement, and dispersion of carbon‐based nanofillers. Moreover, from the perspective of nanocarbon, hybrid nanofillers are divided into three categories: carbon/carbon, carbon/ceramics, and carbon/metal for the first time, and the thermal conductive effect of these hybrid fillers is discussed. Finally, potential areas for future research and development of thermal interface materials are discussed.

Polylactic Acid Composites Reinforced with Eggshell/CaCO3 Filler Particles: A Review

Statistics reveal that egg production has increased in recent decades. This growth suggests there is a global rise in available eggshell biomass due to the current underutilization of this bio-waste material. A number of different applications for waste eggshells (WEGs) are known, that include their use as an additive in human/animal food, soil amendment, cosmetics, catalyst, sorbent, and filler in polymer composites. In this article, worldwide egg production and leading countries are examined, in addition to a discussion of the various applications of eggshell biomass. Eggshells are a rich supplement of calcium carbonate; therefore, they can be added as a particulate filler to polymer composites. In turn, the addition of a lower-cost filler, such as eggshell or calcium carbonate, can reduce overall material fabrication costs. Polylactic acid (PLA) is currently a high-demand biopolymer, where the fabrication of PLA composites has gained increasing attention due to its eco-friendly properties. In this review, PLA composites that contain calcium carbonate or eggshells are emphasized, and the mechanical properties of the composites (e.g., tensile strength, flexural strength, tensile elastic modulus, flexural modulus, and elongation (%) at break) are investigated. The results from this review reveal that the addition of eggshell/calcium carbonate to PLA reduces the tensile and flexural strength of PLA composites, whereas an increase in the tensile and flexural modulus, and elongation (%) at break of composites are described herein.

Capacity Building of Thermal Conductivity in Polymers and Their Composites: A Short Review of the Effect of Various Fillers in Their Composites

In industries like automotive, packaging, structural, electrical, and energy harvesting, polymers and polymer composites have been the preferred material due to their lightweight and long-lasting applications. They are potential replacements for the metal structures used in communication devices, microelectronics, electric vehicles, and generators due to their adaptability and flexibility. However, most of the polymers are not thermal conductors and it difficult to use them in application such as high-performance computing systems, aerospace and electronics. The capacity building of thermal conductivity in the polymers and their composites are current objectives in various applications as compared with metals due to the many advantages of polymers; viz. corrosion resistance and ease of processing. Our study of the literature, as described, here outlines three main features, (a) Various fillers in polymer composites play important roles in the effective thermal conductivity, (b) the effect of filler percentage in thermal conductivity, and (c) various processing method and their effect on the thermal conductivity. This review was aimed to benefit the recent trend of industrial requirements and to highlight the fillers used in polymer composites for various applications.

Modelling effective thermal conductivity in polymer composites: A simple cubic structure approach

In this study, we propose the simple cubic model, a distinctive thermal-conductive mathematics for modelling the effective thermal conductivity in polymer composites, taking both filler size and interface thermal resistance into account. This model is constructed by delineating heat transport paths within simple cubic structural units, leveraging principles involving Fourier's law, minimum thermal resistance, specific equivalent thermal conductivity, and thermal resistance network. Demonstrating broad applicability, the simple cubic model accurately predicts effective thermal conductivity within a 0–40 % volume fraction range of filler in polymer composites, maintaining less than 15 % error. Its robustness is validated across over 100 experimental datasets, encompassing various polymer matrices and granular filler types. This extensive validation underscores the model's efficacy, both with our experimental data and existing literature. The simple cubic model's insightful predictions make it valuable in designing and preparing thermally conductive polymer composites.

Recent Progress in Cellulose Hydrophobization by Gaseous Plasma Treatments.

Cellulose is an abundant natural polymer and is thus promising for enforcing biobased plastics. A broader application of cellulose fibers as a filler in polymer composites is limited because of their hydrophilicity and hygroscopicity. The recent scientific literature on plasma methods for the hydrophobization of cellulose materials is reviewed and critically evaluated. All authors focused on the application of plasmas sustained in fluorine or silicon-containing gases, particularly tetrafluoromethane, and hexamethyldisiloxane. The cellulose materials should be pre-treated with another plasma (typically oxygen) for better adhesion of the silicon-containing hydrophobic coating. In contrast, deposition of fluorine-containing coatings does not require pre-treatment, which is explained by mild etching of the cellulose upon treatment with F atoms and ions. The discrepancy between the results reported by different authors is explained by details in the gas phase and surface kinetics, including the heating of samples due to exothermic surface reactions, desorption of water vapor, competition between etching and deposition, the influence of plasma radiation, and formation of dusty plasma. Scientific and technological challenges are highlighted, and the directions for further research are provided.

Cellulose-Based Oil Palm Empty Fruit Bunch as an Alternative Filler for Latex Application: A Review

Cellulose is a natural polymer with good properties that have caught researchers' attention to utilize these natural resources' potential. Cellulose also has been widely used as an alternative filler to replace inorganic filler in polymer composites. This review discussed the extraction of cellulose from oil palm empty fruit bunch (OPEFB). This review focused on the OPEFB due to the emergence of palm oil plantations which creates a high amount of biomass, whereas OPEFB is one of the major contributors. The utilization of cellulose application in the polymer focused on alternative fillers in latex application. The postulate crosslink mechanism in latex films is also described to highlight the potential of OPEFB as fillers in latex application. The utilization of OPEFB cellulose has the potential to be explore as bio-fillers with also impact the crosslinks mechanism in latex system which can improved the properties in latex composites.

Rheology of Highly Filled Polymer Compositions-Limits of Filling, Structure, and Transport Phenomena.

The current state of the rheology of various polymeric and other materials containing a high concentration of spherical solid filler is considered. The physics of the critical points on the concentration scale are discussed in detail. These points determine the features of the rheological behavior of the highly filled materials corresponding to transitions from a liquid to a yielding medium, elastic-plastic state, and finally to an elastic solid-like state of suspensions. Theoretical and experimental data are summarized, showing the limits of the most dense packing of solid particles, which is of key importance for applications and obtaining high-quality products. The results of model and fine structural studies of physical phenomena that occur when approaching the point of filling the volume, including the occurrence of instabilities, are considered. The occurrence of heterogeneity in the form of individual clusters is also described. These heterogeneous objects begin to move as a whole that leads to the appearance of discontinuities in the suspension volume or wall slip. Understanding these phenomena is a key for particle technology and multiphase processing.

Distribution of Filler in Polymer Composites. Role of Particle Size and Concentration

Distribution of Filler in Polymer Composites. Role of Particle Size and Concentration

Detailed Morphology and Electron Transport in Reduced Graphene Oxide Filled Polymer Composites with a Segregated Structure

Polymer composites of a segregated network structure are dielectric polymer granules coated with electrically conductive nanoparticles at a low content, the quantity of the junctions between the granules determines the composites' mechanical properties, and the percolation network formed by the nanoparticles determines the electrical conductivity. Here, the morphology and electron‐transport properties in reduced graphene oxide (rGO)‐filled composites with a segregated structure based on polyvinyl chloride (PVC), poly(vinylidene fluoride‐co‐tetrafluoroethylene) (P(VDF‐TFE)), and ultrahigh‐molecular‐weight polyethylene (UHMWPE) are studied. Optical and electron microscopies study of the microtome‐formed cross sections have shown the morphology to be dependent on the polymer—the thinnest rGO layers are in UHMWPE‐based composites, the thicker rGO layers are in PVC‐ and P(VDF‐TFE)‐based ones. The electrical conduction of the composites and the rGO‐paper occurs through the same hopping conduction mechanisms within the wide temperature range, which allows to use the composites in applications where pure rGO is considered. Owing to thicker rGO layers open to the environment, PVC‐ and P(VDF‐TFE)‐based composites are more attractive, rather than the UHMWPE ones, in applications where layered materials are needed, for example, in lithium‐ion batteries or supercapacitors. The UHMWPE‐based composites look more promising as electrically conductive materials when mechanical strength is important.