Filler For Thermoplastics Research Articles

Shear property measurement of additively manufactured continuous fibre reinforced plastics by in-plane torsion testing

In-plane shear properties are essential for calculating the plane stress state of composites. Test results for in-plane shear properties of fibre-reinforced polymers (FRPs) are generally obtained with methods that generate multiaxial stress states, and no simple shear response is measured. In this paper, the in plane torsion test method is applied to additively manufactured (AM) continuous FRPs. With this method, planar simple shear loading is achieved for a dedicated, spiral lay-up of the AM specimen. Using digital image correlation, surface strains were obtained for an observed section of the specimen, and shear stress–strain curves were extracted for fibre bundles, co-extruded thermoplastic material, and the composite of both. Shear stiffness and shear strength values are yielded for representative surface areas. Furthermore, the fracture behaviour in shear is discussed. The co-extruded thermoplastic filler material is shown to be the phase where cracks progress is most likely, however as some fibre bundles are split, these can be bridged by the crack. In conclusion, the method is well suited for determination of shear properties of AM continuous FRP material, giving consistent results for the test sample.

Effect of poly ether ether ketone particles on v‐notched shear and drop weight impact behavior of carbon/epoxy composite

AbstractDue to the intrinsic brittleness, low velocity impact (LVI) causes internal invisible damages that drastically degrade the structural qualities of carbon/epoxy composites. The addition of pre‐formed immiscible thermoplastic filler in thermoset matrix offers various advantages over miscible phase separated thermoplastic filler. In this work, poly ether ether ketone (PEEK) micro particles were used to improve the toughness of the carbon/epoxy composite. Mechanical stirring was used to disperse the particles. Composite was fabricated using hand lay‐up process followed by compression molding. The effect of PEEK particles was assessed using in‐plane v‐notched rail shear characteristics, drop weight impact, and compression after impact strength. The addition of PEEK particles significantly improved the in‐plane shear strength and damage tolerance of the carbon/epoxy composite, according to the results.

Effect of the Addition of Thermoplastic Resin and Composite on Mechanical and Thermal Properties of Epoxy Resin.

When the thermoplastic composites reach the service limits during the service, the recovery and utilization are the key concerns. Meanwhile, the improvement of strength, toughness and durability of epoxy resin is the effective method to prolong the service life of materials and structures. In the present paper, three kinds of thermoplastic resins (polypropylene-PP, polyamide 6-PA6 and polyether-ether-ketone-PEEK) and composites (carbon fiber-PEEK, glass fiber-PA6 and glass fiber-PP) were adopted as the fillers to reinforce and toughen the epoxy resin (Ts). The mechanical, thermal and microscopic analysis were conducted to reveal the performance improvement mechanism of Ts. It can be found that adding thermoplastic resin and composite fillers at the low mass ratio of 0.5~1.0% brought about the maximum improvement of tensile strength (7~15%), flexural strength (7~15%) and shear strength (20~30%) of Ts resin. The improvement mechanism was because the addition of thermoplastic fillers can prolong the cracking path and delay the failure process through the load bearing of fiber, energy absorption of thermoplastic resin and superior interface bonding. In addition, the thermoplastic composite had better enhancement effect on the mechanical/thermal properties of Ts resin compared to thermoplastic resin. When the mass ratio was increased to 2.0~3.0%, the agglomeration and stress concentration of thermoplastic filler in Ts resin appeared, leading to the decrease of mechanical and thermal properties. The optimal addition ratios of thermoplastic resin were 0.5~1.0% (PEEK), 1.0~2.0% (PA6) and 0.5~1.0% (PP) to obtain the desirable property improvement. In contrast, the optimal mass ratios of three kinds of composite were determined to be 0.5~1.0%. Application prospect analysis indicated adding the thermoplastic resin and composite fillers to Ts resin can promote the recycling and reutilization of thermoplastic composites and improve the performance of Ts resin, which can be used as the resin matrix, interface adhesive and anti-corrosion coating.

Opoka—Sediment Rock as New Type of Hybrid Mineral Filler for Polymer Composites

The work presents a comprehensive profile of the physicochemical characteristics of opoka sedimentary rock in the context of its use as a hybrid filler for thermoplastics. Determining the functional parameters of the studied filler was the main aim of this research. Thermal treatment leads to changes in its morphology and phase composition. A wide range of physicochemical techniques was used, such as low-temperature nitrogen adsorption, FT-IR, TGA, XRD, optical, and electron microscopy. The susceptibility of the material to micronisation was also tested (ball milling). Due to its widespread occurrence, opoka can be an attractive alternative to fillers such as silica or chalk. In order to verify this statement, polypropylene composites thereof were prepared by melt blending and injection molding, and studied by mechanical testing and microscopic imaging.

Physical–mechanical properties and morphology of filled low‐density polypropylene: Comparative study on calcium carbonate with oil shale and coal ashes

AbstractThe main idea of this research is to explore the prospective of ashes accumulated during the energy production to be used as a filler for thermoplastics. The return of waste for processing into secondary raw materials is cost reducing and nature protective. In this study, low‐density polyethylene filled with CaCO3, burnt coal, and oil shale ash were produced and scrutinized. The optimal extrusion compounding and injection molding parameters are discussed. The effect of different filler load up to 30 wt% on the mechanical properties, structure, and morphology is investigated. It was found that the processing conditions for ash‐filled compounds are similar to CaCO3 filled. Mechanical properties such as tensile and impact strength of ash‐filled composites are also close to CaCo3 filled.

Virtual Approach to the Comparative Analysis of Biomaterials Used in Endodontic Treatment

The importance of endodontics is presented within our own concept of Dentistry Sustainable Development (DSD) consisting of three inseparable elements; i.e., Advanced Interventionist Dentistry 4.0 (AID 4.0), Global Dental Prevention (GDP), and the Dentistry Safety System (DSS) as a polemic, with the hypothesis of the need to abandon interventionist dentistry in favour of the domination of dental prevention. In view of the numerous systemic complications of caries that affect 3−5 billion people globally, endodontic treatment effectively counteracts them. Regardless of this, the prevention of oral diseases should be developed very widely, and in many countries dental care should reach the poorest sections of society. The materials and methods of clinical management in endodontic procedures are characterized. The progress in the field of filling materials and techniques for the development and obturation of root canals is presented. The endodontics market is forecast to reach USD 2.1 billion in 2026, with a CAGR of 4.1%. The most widely used and recognized material for filling root canals is gutta-percha, recognized as the “gold standard”. An alternative is a synthetic thermoplastic filler material based on polyester materials, known mainly under the trade name Resilon. There are still sceptical opinions about the need to replace gutta-percha with this synthetic material, and many dentists still believe that this material cannot compete with gutta-percha. The results of studies carried out so far do not allow for the formulation of a substantively and ethically unambiguous view that gutta-percha should be replaced with another material. There is still insufficient clinical evidence to formulate firm opinions in this regard. In essence, materials and technologies used in endodontics do not differ from other groups of materials, which justifies using material engineering methodology for their research. Therefore, a detailed methodological approach is presented to objectify the assessment of endodontic treatment. Theoretical analysis was carried out using the methods of procedural benchmarking and comparative analysis with the use of contextual matrices to virtually optimize the selection of materials, techniques for the development and obturation of root canals, and methods for assessing the effectiveness of filling, which methods are usually used, e.g., in management science, and especially in foresight research as part of knowledge management. The results of these analyses are presented in the form of appropriate context matrices. The full usefulness of the research on the effectiveness and tightness of root canal filling using scanning electron microscopy is indicated. The analysis results are a practical application of the so-called “digital twins” approach concerning the virtual comparative analysis of biomaterials used in endodontic treatment.

Theoretical modelling of kinetics of glass transition temperature of PEG toughened epoxy

ABSTRACT In this paper, we examined glass transition, a very important parameter that determines the properties and applications of epoxy resins by the innovative approach of kinetic study. The effect of thermoplastic filler Polyethylene Glycol-1000 (PEG-1000) on the kinetics of glass transition temperature of epoxy was analysed by varying the filler loadings and the heating rates. The differential scanning calorimetry curves were plotted at heating rates of 5, 10, 15 and 20°C, respectively and the kinetics of glass transition by varying the heat rates was investigated. Kissinger and Moynihan methods were employed to analyse the glass transition kinetics. The changes in glass transition have been interpreted remarkably with the constrained polymer region of the systems. The improvement in toughness of about ≈ 213% was obtained compared to the neat epoxy with an addition of about 1 wt-% of PEG loading. The toughening mechanisms were elucidated by analysing the scanning electron microscopic images of fractured samples.

Mechanical properties of wollastonite reinforced thermoplastic composites: A review

AbstractWollastonite is a functional filler that has great potential to be used in thermoplastic composites, replacing more expensive reinforcement such as glass fiber. Wollastonite‐reinforced polymer composite materials have attracted the attentions from research field and industries due to their biocompatibility and reinforcing ability in polymers. Due to the relatively high aspect ratio and hardness, wollastonite is able to improve the tensile and flexural strength of polymer composites. Many researches have been conducted to determine various properties of wollastonite reinforced polymer composites such as mechanical, flammability, thermal, and tribological properties in order to explore their potential in various applications. This review will focus on mechanical properties of wollastonite reinforced thermoplastic composites. Overall, it can be concluded that the properties of wollastonite‐filled polymer composites are the function of filler content, adhesion interactions of wollastonite particles with polymer matrix, size and shape of wollastonite particles. Further research and development are needed to widen its application, and these include the use of nano‐size wollastonite which can be produced synthetically as functional filler in thermoplastics.

Alumina Recovery from Industrial Waste: Study on the Thermal, Tensile and Wear Properties of Polypropylene/Alumina Nanocomposites

The investigation on the influences of alumina (Al2O3) particles in nano-sized retrieved from Aluminium (Al) dross was conducted on the tensile, thermal and wear properties of polypropylene (PP) composites. The thermal decomposition method was used to synthesise the micro α-Al2O3 particles from Al-dross, was followed by the wet-milling method to produce the nano α-Al2O3. The PP composites (nano and micro α-Al2O3 particles) were prepared via melt compounding followed by compression molding. The coupling agent was also added to facilitate the particle dispersion. The tensile tests showed the maximum tensile strength and Young’s modulus of both composites to be corresponding to the samples containing 5 wt% of α-Al2O3. The superiority of nano α-Al2O3 on improving the property of PP had also been evident in the abrasive wear performance. A small amount of α-Al2O3 had been adequate in enhancing the thermal stability of PP than that of neat PP. The study on tensile and worn surface with SEM had revealed better adhesion and interaction between the filler and matrix in composites that were treated with coupling agent. The recovery of nano α-Al2O3 particles from Al-dross potentially decreases the quantity of harmful solid waste and can be an effective alternative filler for thermoplastics.

Agricultural wastes preparation, management, and applications in civil engineering: a review

The incineration of agricultural wastes (agro wastes) as a fuel, solid fuel, and/or for the same purposes, resulting in landfilled ash that in most cases makes an environmental problem due to disposal. These landfilled most of the time contain valuable elements such as silica and alumina which are promising alternatives to be used in value-added engineering products. With this regard, the optimal use of these wastes has always been a concern for researchers, and the utilization of them for different purposes is an effective way of management. Although in recent years, the beneficial use of agro waste ashes has been considered by many researchers in different engineering fields, according to the preparation conditions and activation techniques, different kinds of ashes are produces. Therefore, according to the composition of final product, various applications are considered including wastewater treatment, additive for cement industry, and alkali-activated materials, as an additive for production of glass, silicate, pure silica, silicon carbide, refractory materials, as filler in thermoplastics and rubbers, reinforcing agent, and adsorbent in polymer composites and epoxy thermostable polymers, for producing advanced materials such as Silicon nitrite (Si3N4) and magnesium silicide (Mg2Si), and many more. The present paper surveys the preparation steps and techniques for activation of rice husk ash as one of the most used agro waste ash and its applications in engineering fields.

Preparation of graphene-based compounds with improved dispersion by a two-stage production process

Abstract Graphene can be used as a functional filler in thermoplastics in order to improve the mechanical and electrical properties, among other things. In the case of high exfoliation and dispersion state, disproportionate increases in compound properties can be achieved even with the lowest filler content. Accordingly, dispersion plays a decisive role here. Up to now, it has not been possible to achieve sufficient dispersion under near-industrial conditions on a twin-screw extruder due to the achievable shear energy input and short residence times. Therefore, this study presents a two-stage compounding process with the aim of improving graphene dispersion. First of all, a predispersion step is carried out in a solvent with the aid of ultrasonic treatment. The predispersed graphene solution is then added to the twin-screw extruder for incorporation. The solvent is removed by a multi-stage degassing process. The results show an improved dispersion compared to conventional addition of the graphene in powder form. In particular, the elongation at break of graphene-based composites can be increased from 13.6% to 57.1% by the increased dispersion.

Water-Based Processing of Fiberboard of Acrylic Resin Composites Reinforced With Cellulose Wood Pulp and Cellulose Nanofibrils

Despite the great potential of cellulose wood pulp and cellulose nanofibrils as reinforcing filler in thermoplastics, its use is limited due to its tendency to form agglomerates and due to its high hydrophilic character. Here... | Find, read and cite all the research you need on Tech Science Press

Surface Modification of Wood Flour via ARGET ATRP and Its Application as Filler in Thermoplastics.

Wood flour is particularly suitable as a filler in thermoplastics because it is environmentally friendly, readily available, and offers a high strength-to-density ratio. To overcome the insufficient interfacial adhesion between hydrophilic wood and a hydrophobic matrix, a thermoplastic polymer was grafted from wood flour via surface-initiated activators regenerated by electron transfer-atom transfer radical polymerization (SI-ARGET ATRP). Wood particles were modified with an ATRP initiator and subsequently grafted with methyl acrylate for different polymerization times in the absence of a sacrificial initiator. The successful grafting of poly(methyl acrylate) (PMA) was demonstrated using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and water contact angle (WCA) measurements. To confirm the control over the polymerization, a cleavable ATRP initiator was immobilized on the particles, allowing the detachment of the grafted polymer under mild conditions. The grafted particles were incorporated into a PMA matrix using solvent casting and their influence on the mechanical properties (Young’s modulus, yield strength, and toughness) of the composite was investigated. Tensile testing showed that the mechanical properties improved with increasing polymerization time and increasing ratio of incorporated grafted particles.

The Effect of Ultrasonic Additive Manufacturing on Integrated Printed Electronic Conductors

Ultrasonic additive manufacturing (UAM) is a low temperature manufacturing method capable of embedding printed electronics in metal components. The effect of UAM processing on the resistivity of conductive tracks printed with five different conductive pastes based on silver, copper or carbon flakes/particles in either a thermoplastic or thermoset filler binder are investigated. For all but the carbon-based paste, the resistivity changed linearly with the UAM energy input. After UAM processing, a resistivity increase of more than 150 times was recorded for the copper based thermoset paste. The silver based pastes showed a resistivity increase of between 1.1 and 50 times from their initial values. The carbon-based paste showed no change in resistivity after UAM processing. Focussed ion beam microstructure analysis of the printed conductive tracks before and after UAM processing showed that the silver particles and flakes in at least one of the pastes partly dislodged from their thermoset filler creating voids, thereby increasing the resistivity, whereas the silver flakes in a thermoplastic filler did not dislodge due to material flow of the polymer binder. The lowest resistivity (8 × 10−5 Ω cm) after UAM processing was achieved for a thermoplastic paste with silver flakes at low UAM processing energy.Graphical

Evaluation of Waste from Aluminum Industry as Filler in Polypropylene Composites

White aluminum (Al) dross is the waste or by-product generated from the smelting of Al. Improper disposal of this waste will affect the sustainability of the environment. This study was aimed at investigating the feasibility of Al dross as a thermoplastic filler. Various content of Al dross (10–40 wt.%) was blended with polypropylene (PP) using an extruder. An improvement in thermal and flame resistance properties was evident, which was associated with the presence of aluminum hydroxide elements in Al dross as revealed from x-ray diffraction analysis. It was shown that the higher Al dross content in PP did cause the composites to possess high stiffness and low crystallinity. An advantage in wear properties further showed that the Al dross can be used as a filler for thermoplastics.

Toughening of Epoxy with Preformed Polyethylene Thermoplastic Filler

The potential of polyethylene as a thermoplastic filler towards improving the fracture properties of epoxy resin was explored. Oxo-degradable films were subjected to thermo-oxidative exposure, and the oxidized polyethylene (OPE) was extracted with acetone to remove low molecular weight products (APE). The presence of functionalities led to its homogenous dispersion in the epoxy matrix. Blending of epoxy with OPE and APE led to significant improvement in both quasi-static and impact properties, as evidenced by 44% increase in GIC and 21% increase in impact strength at loadings of 3% w/w. The strain rate sensitivity of the composites was also investigated.

Torrefied biomass filled polyamide biocomposites: mechanical and physical property analysis

Biobased fillers in thermoplastics have seen increased usage over the last several years. The increased usage of biobased fillers follows the ever-increasing thrust to reduce petroleum and synthetic petrochemical product consumption. The study of polyolefin-based biocomposites is well established, however, the incorporation of biomass fillers into engineering thermoplastics still proves to be challenging. For engineering thermoplastics, the increased processing temperatures lead to degradation of the biomass, often detrimental for the mechanical performance and visual appearance of the end product. The goal of this work was to evaluate the effectiveness of agricultural by-products as fillers in polyamides, while minimizing the effects of increased processing temperatures. Through the use of torrefaction, polyamide biocomposites were produced and shown to have comparable mechanical properties to the neat matrix. Torrefied sunflower hulls and flax shive were shown to produce tensile strengths within 70 % of the neat matrix, increase elastic modulus by 150 %, maintain flexural strengths within 94 % of the neat matrix, increase flexural modulus by 154 %, and decrease the absorption of environmental moisture by as much as 50 %.

Green composites of polypropylene and eggshell: Effective biofiller size reduction and dispersion by single-step processing with solid-state shear pulverization

Abstract Eggshell (ES), a waste byproduct from food processing and hatcheries, contains ∼95% calcium carbonate (CC), making it a potentially attractive, less expensive substitute for commercial CC. Past work used complex grinding–sieving and/or chemical modification steps to aid in dispersing ES in polymers such as polypropylene (PP). Both steps add to the cost and reduce the green aspect of the composite. Here, green composite materials of PP with 5–40 wt% unmodified ES shards of several centimeters in size are directly processed using continuous, single-step solid-state shear pulverization (SSSP). Electron microscopy and particle size analysis show very good dispersion with some ES particles near the nanoscale in the composite. Well-dispersed ES particles dramatically increase PP crystallization rates with a 5–7% increase in PP crystallinity. The very good dispersion leads to a major increase in Young’s modulus (87% increase relative to neat PP for 40 wt% ES) and a modest increase in hardness; composites exhibit reductions in yield strength, elongation at break, and impact properties. Mechanical and crystallization properties are equal to or better than the best literature data for PP/ES composites without chemical modification made by multi-step approaches involving melt processing. In addition, the composites exhibit high thermal degradation temperatures compared to neat PP, indicating the potential for ES to improve processing stability. Composites with 20–40 wt% ES exhibit solid-like rheological response with no crossover of shear storage and loss moduli. Nevertheless, PP/ES composites retain viscosities close to that of neat PP at shear rates experienced in melt processing. Overall, property enhancements resulting from superior dispersion of ES in PP achieved by SSSP reveal ES to be a promising green filler for thermoplastics.

Effect of Cenosphere Concentration on the Mechanical, Thermal, Rheological and Morphological Properties of Nylon 6

Cenospheres are widely used as filler in thermoset plastics and concrete mainly for density reduction of the material. But there is no work noted of using cenosphere as filler in thermoplastics. In this paper cenosphere concentration was varied from 0 to 10 phr of nylon 6 and the effect of the same on the mechanical, thermal, rheological and morphological properties of the composite were studied. Elongation was found to have increased by 83% and impact strength by 44% at 2.5 phr loading of cenosphere. Flexural strength increased upto 25% at 10 phr content of cenosphere.

Boron Nitride in Thermoplastics (for LED Housings)

Boron nitride (BN) is increasingly being used as a filler in thermoplastics, primarily to increase the thermal conductivity of the resins. Filler-reinforced plastics are being considered to replace traditionally metal parts in a number of markets, with applications such as under-hood automotive parts, sensors and housings for motors, LEDs, and other electronic devices. When BN powders are used as fillers in resins, the BN-resin composite materials also demonstrate anisotropic properties, largely determined by the orientation of the platy BN crystals in the final part. To overcome this problem of anisotropy, boron nitride powders have been developed which are agglomerates of single crystal. In such agglomerate grades, platy BN crystals are held together to form a larger particle to randomize their orientation. Such BN powder grades, broadly called agglomerate grades, demonstrate more isotropic properties than do single crystal BN grades. One of the biggest challenges of using agglomerate BN grades is to preserve the structure through all the processing steps. In the case of thermoplastics, the BN agglomerates can break down during the extrusion step and/or the molding step. Both the screw configuration during extrusion and the flow configuration during molding determine the extent of shear of the BN agglomerates. The thermal conductivity of single crystal platelet and agglomerate boron nitrides in a thermoplastic resin is examined in this paper to consider and explain the effect of particle morphology. The anisotropic properties will be characterized on BN-plastic composite parts. The effect of screw configuration during extrusion and molding conditions on the thermal conductivity and other physical strength properties will also be examined and the trade-offs will be discussed.