Reinforcement Filler Research Articles

Novel Hybrid Biomass Anti-Aging Filler for Styrene-Butadiene Rubber Composites with Antioxidative and Reinforcing Properties.

Antioxidants are normally utilized to extend the service life of polymers due to the strong reducibility of the phenolic hydroxyl group of the hindered phenol structure. Inspired by this characteristic, we have introduced green tea polyphenol (TP) supported on a silica surface containing considerable phenolic hydroxyl groups to obtain a novel biomass anti-aging filler (BAF, denoted as silica-s-TP) to reinforce and improve the anti-aging property of rubber composites. The applying of silica-s-TP to enhance the thermal-oxidative stability and ultraviolet light (UV) aging resistance of styrene-butadiene rubber (SBR) was evaluated. The hybrid biomass anti-aging filler could not only uniformly disperse in the rubber matrix, giving rise to the excellent mechanical properties, but also enhance the properties of thermal-oxidative stability and UV aging resistance with the increasing silica-s-TP content of SBR distinctly. This study provides a mild and environmentally friendly strategy to prepare the functional biomass filler, which could be applied as not only a reinforcement filler but also an anti-aging additive in “green rubber”.

Evaluation of tribological performance of copper-based composites containing nano-structural 2D materials and their hybrid

The current investigation is aimed at evaluating and comparing the tribological performance of Cu-based composites containing a fixed amount standalone 2D layered materials (MoS2 and reduced graphene oxide; rGO) and their hybrid rGO-MoS2. The study also intends to explore the role of electronic work function of the 2D reinforcements in affecting the tribological performance of the composites. Results indicate that friction and antiwear properties of composites are governed by inherent lubrication properties of reinforcement fillers, interfacial interaction of cooper matrix with reinforcement phase, and the electronic work function (EWF). The study is expected to open up new directions in developing hybrid 2D materials as potential solid lubricants for fabricating metal based self-lubricating composites with improved tribological performance.

FABRICATION OF COFFEE BEAN POWDER FILLED EPOXY COMPOSITES FOR ENHANCEMENT OF MECHANICAL PROPERTIES

In the recent advancement researchers have found out that coffee bean is a natural fiber. Influence of coffee bean natural filler reinforcement (5, 10, 15, 20, 25 and 30% mass fraction) on the mechanical properties of Epoxy LY556 composite, fabricated using compression moulding was analyzed in this study. The mechanical properties were determined for 25% mass fraction of espresso bean natural filler composite. The coffee bean powder is being filled with epoxy composites to increase and enhance the mechanical properties. Presently, the contribution of composites is certain to happen in most engineering applications because of their superior powers such as weight, specific strength, modulus and corrosion resistance (Keyoonwong et al. 2012). It is found that synthetic polymers and manmade fibers were found to be threatening factor in the aspect of environmental worries. Harmful gases and stagnant can also be emitted as the composites from these composites by waste land material. So, it is time to make a positive environmental impact with increased advancement.

Development of an active packaging system containing zinc oxide nanoparticles for the extension of chicken fillet shelf life.

The casting method was employed to prepare gelatin‐based nanocomposite films containing different concentrations of cellulose nanofiber (CNF) as a reinforcement filler (2.5%, 5%, and 7.5% w/w of gelatin) as well as zinc oxide nanoparticles (ZnO NPs) as an antimicrobial agent (1%, 3%, 5%, and 7% w/w of gelatin). The results showed that the incorporation of 5% CNFs (optimum concentration) significantly boosted the films' stiffness (YM; by 47%) and strength (TS; by 72%) but decreased its flexibility (EAB; by 28%), water vapor permeability, and moisture absorption. The best G/CNF film antibacterial activity was provided by the 5% concentration of ZnO NPs according to the disk diffusion assay; Gram‐positive bacteria were inhibited significantly more than Gram‐negative bacteria. The antimicrobial efficacy of the G/CNF/ZnO NPs film as a food packaging material was assessed via counts of Staphylococcus aureus and Pseudomonas fluorescens inoculated on chicken fillets (as a food model) in the treatment (G/5% CNF/5% ZnO) and control groups (plastic bag). The antibacterial film led to a significant reduction in the bacterial load of the chicken fillets (p < .05), especially against the Gram‐positive strain. This study illustrated that G/CNF/ZnO NPs films can be utilized as active packaging to prolong the shelf life of different perishable foods such as meat.

Carbon nanotube–reinforced polymer composite for electromagnetic interference application: A review

Abstract The growth of the application of electronic devices has created a new form of pollution known as noise or radio frequency interference, electromagnetic radiation, or electromagnetic interference (EMI), which results in the malfunction of equipment. A new carbon-based polymer composite has been unlocked through the discovery of polymer composites. Carbon nanotubes (CNTs) have shown potential as reinforcement fillers in polymer to enhance an EMI shielding material owing to their large specific surface area, well-defined 3D networking structure, and unique electronic structure. The main focus of this review is the role of CNT as fillers in intrinsic conducting polymer and conducting polymer composite. The factors that influence EMI shielding performance are also included in this review. The roles of the size; shape; and electronic, mechanical, and chemical properties of nanomaterials in tuning the EMI shielding effectiveness of polymer hybrid are emphasized. The structural design of CNT polymer composite has been reviewed as well. Future research direction has been proposed to overcome the current technological limitations and realize the most advanced EMI shielding materials for future use. The composites have a potential to replace traditional shielding materials owing to their advantageous properties.

Converting dead leaf biomass into activated carbon as a potential replacement for carbon black filler in rubber composites

In this work, the feasibility of converting dead leaf biomass into green activated carbon for use as a reinforcement filler in natural rubber composites was assessed. The dead leaf activated carbon (DLAC) was prepared by pyrolysis at 550, 700, 900, and 1000 °C at a heating rate of 10 °C min−1 under nitrogen gas flow of 100 cm3 min−1 and was activated by CO2 gas at the same flow rate when the pyrolysis temperature was reached. The properties of DLACs were characterized by particle size analysis, density, scanning electron microscopy, elemental energy-dispersive X-ray spectroscopy and Raman spectroscopy. The results revealed that the DLAC obtained by pyrolysis at 1000 °C had a small particle size of 28.86 μm; a highly porous structure; high carbon purity, at 82.58%; and a low density, at 1.588 g cm−3. The effect of different DLAC contents (5, 10, and 15 phr) on the curing properties and the physical and mechanical performance of the rubber composites was investigated and compared with rubber composites containing carbon black (CB). The results showed that the addition of DLAC increased the maximum torque and reduced the scorch and cure times. The tensile strength for rubber composites containing 15 phr of DLAC increased by 8%, the M100 and M300 improved 40%, and the elongation at break and crosslink density decreased by approximately 5% and 24%, respectively. The studied DLAC is a promising, cost-effective alternative to commercial carbon black for improving the performance of rubber composites.

The synergic influence of carbon nanotube and nanosilica on the compressive strength of lightweight concrete

Nanomaterials, owing to their extraordinary properties are known to improve the performance of concrete, are widely used in cementitious materials. Many studies have been conducted so far to understand the effects of inclusion of nanomaterials on the concrete while less studies have been conducted on Light Wight Concrete (LWC) especially on the synergic effect of nanomaterials.The influence of carbon nanotubes (CNT) and nanosilica (NS) as reinforcement fillers to increase the compressive strength of lightweight concrete using expanded clay were investigated in this study. Eight batches of samples were made by mixing CNT and NS using ultrasonication technique into the concrete mix, with one being a control system without nano reinforcement fillers to be used as a reference batch. The optimum substitution percentage of 3% for nano reinforcements was incorporated into the concrete by varying the ratio of CNT and NS. The compressive strength tests were conducted according to BS EN 12390: 2000 and BS EN 12350: 2009. From the results, it was found that incorporating 1% NS and 2% CNT, the highest compressive strength of 10.72 MPa can be achieved at 28 days, with percentage of 39% as compared to control sample. However, the incorporation of 3% CNT resulted in a negative effect on the compressive strength gain by a significant drop in compressive strength of −16% at 28 days. Field emission scanning electron microscope (FESEM) test was conducted to further observe the compressive strength behaviour for the obtained results.

Tribological Behavior of Micro Coir Filler Reinforced Polymer Composite under Dry, Wet, and Heated Contact Condition

ABSTRACT This article speculated the wear and frictional performance of treated micro coir filler reinforced polymer composite. The surface of the coir filler is modified by the alkali treatment and the composite is prepared with a variation of coir filler reinforcement. The investigation of wear test is steered under dry sliding contact, wet and heated contact state using the pin-on-disk multi-tribometer counter to a stainless steel disc. Experiments 1were conducted considering three different parameters, namely, different normal load (5–40 N), sliding velocity 100 cm/s, and sliding distance (0–2000 m). The results showed that the wear behavior of coir filler-reinforced composite is highly dependent on operating parameters and filler reinforcement. The specific wear rate is lesser in wet contact conditions compared to dry and heated contact conditions. Moreover, lower coir filler loading presented enhanced wear presentation related to the higher filler loading composite. From microscopic images, some micro and macro cracks, debonding, and plastic deformation are witnessed on the worn surfaces of the composite.

Effects of kenaf filler reinforcement on mechanical properties of molded polypropylene composites: A particle size study

The combination of natural fibers in petroleum plastic soften industrial footprints on the environment. Plastic matrix can be filled with renewable resources leading to a greener composite that is biodegradable. This paper focuses on particulate kenaf filler modification and its affects on the properties of polypropylene, processing techniques and the use of particle size filler for improving linkages between fiber and polymeric matrixes.

A comprehensive review on mechanical, electromagnetic radiation shielding, and thermal conductivity of fibers/inorganic fillers reinforced hybrid polymer composites

AbstractPeripheral such as aerospace, armor, sensors, heat exchanger, automobile, storage, and any other electronic equipment are frequently subjected to varying mechanical and thermal stress, which substantially influence their reliability, life cycle, and performance. The aerospace sector, for example, is in constant research for the decrement in mass to achieve higher fuel efficiency through light weighting approach. It is due to the specific parameters that advanced polymer composites exhibit, there are growing research interests in heat management schemes, where both higher thermal characteristics and strength with significantly lower density are simultaneously essential. In the same manner, nanohybrid particles are commonly utilized as reinforcement fillers to enhance mechanical, electromagnetic shielding efficiency, and thermal characteristics of any polymer matrices. This survey discusses the polymer‐based nanocomposites incorporated with hybrid nanoparticles for applications in high‐performance materials. The subsequent interaction between the selected polymer matrix and hybrid nanofillers, which affects the characteristics of the polymer‐based nanocomposites: mechanical, electromagnetic radiation shielding efficiency as well as thermal conductivity have been critically reviewed. The hybrid nanoparticles' synergy facilitates effective dispersion without damaging the structures of the nanofillers tend to optimized electrical properties, thermal conductivity, and higher overall functionality of the fabricated nanocomposites.

Effect of different filler reinforcement on poly-ether-ether-ketone based nanocomposites for bearing applications

This study investigates the effect of dispersion of nanofiller reinforcement high performance polymer matrix to enhance the thermo-mechanical properties for bearing application. Polyetheretherketone (PEEK) matrix is reinforced with acid fucntionalized multiwalled carbon nanotubes ( f-MWCNTs) and similar matrix was then reinforced with nano tungsten carbide (nano WC) to comparatively present their mechanical, thermal and morphological properties. The Nanocomposites were prepared via melt compounding method followed by injection moulding technique. The PEEK/ f-MWCNT s nanocomposite exhibited better property enhancement than the PEEK/nano WC. Spectroscopical analysis confirmed the effectiveness of improved interfacial adhesion between PEEK and f-MWCNTs. Transmission Electron Microscope (TEM) micrograph depicted improved dispersion of f-MWCNTs in PEEK matrix than that of nano WC. Due to improved interfacial interaction between f-MWCNT s and PEEK, this resulting nanocomposite showed better mechanical, thermal and morphological properties than PEEK/nano WC. Due to ceramic nature of nano WC and higher density difference the agglomeration of particles occurred leading to lower properties.

Bio-based rigid polyurethane foam prepared from apricot stone shell-based polyol for thermal insulation application – Part 2: Morphological, mechanical, and thermal properties

The procedure for the liquefaction of apricot stone shells was reported in Part 1. Part 2 of this work determines the morphological, mechanical, and thermal properties of the bio-based rigid polyurethane foam composites (RPUFc). In this study, the thermal conductivity, compressive strength, compressive modulus, thermogravimetric analysis, flammability tests (horizontal burning and limited oxygen index (LOI)) in the flame retardants), and scanning electron microscope (SEM) (cell diameter in the SEM) tests of the RPUFc were performed and compared with control samples. The results showed the thermal conductivity (0.0342 to 0.0362 mW/mK), compressive strength (10.5 to 14.9 kPa), compressive modulus (179.9 to 180.3 kPa), decomposition and residue in the thermogravimetric analysis (230 to 491 °C, 15.31 to 21.61%), UL-94 and LOI in the flame retardants (539.5 to 591.1 mm/min, 17.8 to 18.5%), and cell diameter in the SEM (50.6 to 347.5 μm) of RPUFc attained from liquefied biomass. The results were similar to those of foams obtained from industrial RPUFs, and demonstrated that bio-based RPUFc obtained from liquefied apricot stone shells could be used as a reinforcement filler in the preparation of RPUFs, specifically in construction and insulation materials. Moreover, liquefied apricot stone shell products have potential to be fabricated into rigid polyurethane foam composites.

The fabrication of flexible and oxygen barrier cellulose nanofiber/polylactic acid nanocomposites using cosolvent system

AbstractThe main disadvantages of polylactic acid (PLA) for food packaging applications are its brittleness and poor gas barrier properties. The purpose of this study is to evaluate the potential usability of triethyl citrate (TEC) and cellulose nanofiber (CNF) in PLA to obtain bio‐based films with optimal properties. The incorporation of CNF as reinforcement fillers in polymer matrix has long been debated due to its difficulties to disperse uniformly in hydrophobic polymer matrix attribute to their hydrophobic nature. In order to overcome this problem, different feeding method for CNF into the mixer was studied, and CNF/PLA nanocomposites were characterized. It was found that CNF was successfully dispersed in the PLA matrix through the TEC‐CNF suspension, which greatly improved tensile strength and flexibility of the CNF/PLA nanocomposites. The oxygen barrier property was enhanced up to 47.3% (16.99 cc·mm/m2·day·atm) with the increase loading of 0.25, 0.50, and 1 wt% of CNF. Moreover, the dynamic mechanical analysis showed that the low tan delta peak of CNF/PLA nanocomposites (48.25°C) was shifted to high peak (52.99°C) due to incorporation of TEC; indicates an improved of thermal stability of the composites. Overall, the t‐CNF/PLA nanocomposites show a great feasibility for various eco‐friendly flexible packaging applications.

Micromechanics of Stress-Softening and Hysteresis of Filler Reinforced Elastomers with Applications to Thermo-Oxidative Aging.

A micromechanical concept of filler-induced stress-softening and hysteresis is established that describes the complex quasi-static deformation behavior of filler reinforced rubbers upon repeated stretching with increasing amplitude. It is based on a non-affine tube model of rubber elasticity and a distinct deformation and fracture mechanics of filler clusters in the stress field of the rubber matrix. For the description of the clusters we refer to a three-dimensional generalization of the Kantor–Webman model of flexible chain aggregates with distinct bending–twisting and tension deformation of bonds. The bending–twisting deformation dominates the elasticity of filler clusters in elastomers while the tension deformation is assumed to be mainly responsible for fracture. The cluster mechanics is described in detail in the theoretical section, whereby two different fracture criteria of filler–filler bonds are considered, denoted “monodisperse” and “hierarchical” bond fracture mechanism. Both concepts are compared in the experimental section, where stress–strain cycles of a series of ethylene–propylene–diene rubber (EPDM) composites with various thermo-oxidative aging histories are evaluated. It is found that the “hierarchical” bond fracture mechanism delivers better fits and more stable fitting parameters, though the evolution of fitting parameters with aging time is similar for both models. From the adaptations it is concluded that the crosslinking density remains almost constant, indicating that the sulfur bridges in EPDM networks are mono-sulfidic, and hence, quite stable—even at 130 °C aging temperature. The hardening of the composites with increasing aging time is mainly attributed to the relaxation of filler–filler bonds, which results in an increased stiffness and strength of the bonds. Finally, a frame-independent simplified version of the stress-softening model is proposed that allows for an easy implementation into numerical codes for fast FEM simulations

Enhanced mechanical properties of alloyed copper matrix composites reinforced with partially-unzipped carbon nanotubes

Sufficient interfacial contact and adhesion are important factors for ensuring effective load transfer in carbon nanotubes (CNTs)-reinforced copper matrix composites (CMCs). In this study, a chemical unzipping method and matrix-alloying (addition of Cr) were integrated to solve these two challenges in CMCs. The results showed that partially-unzipped CNTs (PUCNTs) improved the restricted interfacial contact areas of CNTs. Furthermore, the graphene layers of PUCNTs might improve the interfacial shear strength, and fully utilize the load transfer capacity of the inner walls. Trace amounts of interfacial carbides (Cr7C3 or Cr23C6) were formed in situ at the PUCNTs/CuCr interface, which further improved the interfacial bonding between PUCNTs and the CuCr matrix. The ultimate tensile strength (382.9 MPa) and elongation (37.02%) of the 2 vol% PUCNTs/CuCr composite were higher than similar reported materials. A balance between the strength and ductility of the PUCNTs/CuCr composites was obtained. This was ascribed to the combined effects of the interfacial carbides and interfacial contact area, which improved the load transfer ability and interfacial adhesion, and also promoted dislocation accumulation ability of the PUCNTs. The strengthening effect of PUCNTs was also investigated using the correctional shear-lag strengthening and dislocation strengthening models. This work shows that PUCNTs are better reinforcement fillers than CNTs for enhancing the mechanical properties of CMCs.

Tribological properties of polyimide composites reinforced with fibers rubbing against Al2O3

Reinforcing fillers are of great importance in tribological performance and tribofilm formation of polymeric composites. In this study, the tribological properties of aramid particle (AP) and short carbon fiber (SCF) reinforced polyimide (PI) composites were added to hexagonal boron nitride (h-BN), and silica (SiO2) nanoparticles sliding against alumina were comprehensively investigated. When sliding occurred with AP-reinforced PI composites, the tribological properties were not closely depended on the pressure × velocity (p × ν) factors and the nanoparticles. The interactions between AP and its counterpart could not induce tribo-sintering of the transferred wear debris. As such, the tribofilm seemed to be in a viscous state, leading to higher friction and wear. However, the inclusion of hard SCF into the PI matrix changed the interfacial interactions with alumina. A robust tribofilm consisting of a high fraction of silica was generated when the SCF-reinforced PI was added to the SiO2 nanoparticles. It exhibited a high load-carrying capability and was easily sheared. This caused a significant decrease in the friction and wear of the PI composite at 8 MPa·1m/s. Moreover, due to their high melting point, few h-BN nanoparticles were observed in the tribofilm of the SCF-reinforced PI when hexagonal boron nitride was added.

Valorization of Cotton Industry Byproducts in Green Composites with Polylactide

New sustainable green composites based on polylactide (PLA) and cotton industry byproducts were successfully manufactured by extrusion, and subsequently by conventional injection molding. Cottonseed flour was used as reinforcement filler and modified cottonseed oil (epoxidized and maleinized cottonseed oil, ECSO and MCSO respectively) were used to improve filler-polymer matrix interactions among the interface. Mechanical properties were obtained by standard tensile, flexural, Shore D hardness and impact Charpy tests, while the surface morphology characterization on fractured specimens was carried out by using field emission scanning electron microscopy. Thermal properties were obtained by differential scanning calorimetry and the effect of both cottonseed flour and chemically-modified cottonseed oil was evaluated on dynamic mechanical behavior of the obtained composites. Unlike typical lignocellulosic fillers, 15 wt% cottonseed flour does not lead to more brittle materials due to stress concentration phenomena. In fact, cottonseed flour provides improved toughness and elongation at break (mechanical ductile properties) compared to neat PLA without any other compatibilizer. Addition of both epoxidized and maleinized cottonseed (7.5 wt%) has a positive effect on improving ductile behaviour of composites, thus leading to new green composites with good balance between processability and overall properties. In particular, the impact strength is remarkably improved which plays a key factor in these composites since PLA is, intrinsically, a brittle polymer.

Surface cationic functionalized nano-hydroxyapatite – Preparation, characterization, effect of coverage on properties and related applications

Functionalized nano-hydroxyapatite (nHAp) was obtained by wet chemical technique, using arginine (Arg) or polyethylenimine (branched-bPEI, or linear-LPEI) as cationic modifiers and dispersing agents. TEM, FT-IR, SEM, DLS and WAXD characterization results showed that the prepared nanoparticles possessed needle- or plate-like morphologies and Arg and PEI were successfully grafted onto nHAp. LPEI functionalized nHAp exhibited a good similitude with biological apatite and the best DNA binding ability. In addition, the incorporation of nHAp/LPEI nanoparticles within collagen/dimethylsilanediol hyaluronate-based porous matrices pointed out a significant improvement of the compressive modulus of biocomposites: up to a six-fold increase, compared with the polymer matrix without fillers. Moreover, the composite sponges revealed high toughness during five consecutive compression tests without any permanent deformation and cracks. Therefore, nHAp/LPEI nanoparticles could be considered promising materials for biomedical applications, like gene carrier or reinforcement filler with strong interfacial adhesion in biocomposites for bone engineering.

Transformation of Bulk Alloys to Inorganic Nanowires

One-dimensional (1D) nanomaterials, namely nanowires (NWs), nanotubes and nanofibers, have emerged as feasible building blocks for the next generation of devices and materials, with applications envisioned in electronics, sensors, energy technologies and water purification [1]. Because of their high strength and modulus, 1D materials are seen as reinforcement fillers for metal, polymer, epoxy, and glass composites. Remarkably, the reduction of the diameter of the 1D materials from 1000 nm by the factor of 10-100 can dramatically increase their mechanical properties. In particular, the Al2O3 1D materials with the diameters of the sub 50 nm are believed to exhibit superior tensile strength and modulus, as predicted theoretically (tensile strength 20 GPa) [2], which is of tremendous importance to the field of engineered composites, especially taking into account availability of alumina, its light weight and low cost. However, the synthesis of ceramic 1D materials embraces outstanding challenges with a use of complicated reaction techniques.Here, we demonstrate an unexpected discovery of the synthesis of metal-organic Al alkoxide NWs with tunable diameters (40-1000 nm) and high aspect ratios (1,000+) upon exposure of bulk bimetallic Al-Li alloy to alcohols at ambient temperatures and pressures without the use of any catalysts, porous templates, corrosive chemicals or external stimuli [3, 4]. We further demonstrate a conversion of metal-organic Al alkoxide NWs to the corresponding ceramic Al2O3 NWs upon heating. We demonstrate the crucial parameters of controllable growth of the metal-organic NWs, such as composition of the alloy, molecular structure of the NWs, and the strain energy minimization of alloy grains at the reactive interface. We also show the cost-effective condition of the metal-organic alkoxide NWs synthesis by reducing the content of Li metal in alloy from 20 to 5wt.%. By utilizing the solution and solid-state nuclear magnetic resonance, we provide sufficient characterization rigor of the molecular structure of the metal-organic NWs. The conditions of the transformation of metal-organic NWs to oxide ceramic NWs and the microstructure of ceramic oxide NWs, which influence their mechanical properties will be additionally discussed.We will also demonstrate the technology of the replacement of conventional polymer separators for Li-ion batteries (LIBs) by thermally stable, flexible, and wettable binder-free fabric from Al2O3-cellulose NWs. Because of the easiness in preparation and economical attractiveness, we foresee that our accessible and low-cost membranes will elicit as fundamental low-cost filler materials in LIBs.

Enhanced the Antibacterial and Mechanical properties of UHMWPE by Addition Sort Fibers of Polyacrylonitraile PAN, Graphene Nanoplate (GNP) and Hydroxyapatite (HAp)

The UHMWPE is a gold material in total joint replacement due to excellent properties but with the time was degradation therefor, In present study it was reinforced with 5% short fibers of polyacrylonitriale (PAN) and different weight fraction (0.3, 0.8 and 1.3)% of graphene nanoplate (GNP) and hydroxyapatite (HAp) to increase the mechanical properties (flexural strength, flexural modulus, compression strength and hardness) due to good bonding between fibers and nanoparticles (GNP, HAp) with polymer which improved the loud transfer from matrix to reinforcement phases, and also attributed to good mechanical properties of reinforcement fillers. Moreover, these fillers maintained the antibacterial properties to avoid infection which can happened per implantation of knee joint replacement.