Polymer Matrix Materials Research Articles

Development of fabric-reinforced polymer matrix composites using bio-based components from post-consumer textile waste

Textile waste fiber-reinforced polymer matrix composites are usually reinforced with fiber, bands, fabrics, tows, woven and non-woven textiles, it is also possible to combine different types of materials in one composition. Individual textile plies of a polymer matrix component can be reinforced. This is a reason why the different textile waste are increasingly use it as a bio-based components in structural materials like sandwich structure composites with multiple layers bound in a monolith by a polymer matrix material. Also, hybrid sandwich structure composites can be manufactured, combining different textile waste plies with carbon fiber and/or glass fiber reinforcement. Having in view that a cotton fibers (i.e. denim or chambray weave) and bast fibers (i.e. jute, flax or hemp hessian fabric), as woven textile materials, destined to the textile waste fiber-reinforced polymer matrix composites are highly mouldable, lightweight and tough, several possibilities for industrial applications, sustainable material for architectural and consumer products along with other custom production make this bio-based products unique. In our research, polymer matrix based composite structures were studied by using different natural-reinforcements from eco-friendly, breathable, biodegradable and recyclable post-industrial and post-consumer waste (woven fabrics made of cotton fibers – like denim textile fabric and bast fibers – like jute hessian fabric bags).

Effect of fiber reinforcement on the open hole tensile strength of 3D printed composites

Initially, Fused Deposition Modeling (FDM) based 3D printed parts are only used as prototyping rather than the functional components. However, due to new advancements in the FDM process and its ability to add continuous fibers into the polymer parts, FDM made part can now be used as functional parts. Composites fabricated from the FDM process can be used in aerospace and automotive applications. Still, the applications of FDM made parts are limited due to the lack of critical information about the reliability and mechanical properties of the components. Therefore, in the present investigation, the effect of fiber reinforcement on the open hole tensile strength of the FDM printed part is investigated. Onyx as a polymer matrix material and HSHT (High Strength High Temperature) fiberglass as a continuous fiber reinforcement are used for the study. It is observed that the fiber reinforcement into the polymer matrix significantly increases the open hole tensile strength, but it also increases the specimen weight and printing time.

Reducible, Recyclable and Reusable (3R) Hydrogel Electrolyte Membrane Based on Physical & Chemical Bi-networks and Reversible Sol-Gel Transition

Hydrogel electrolytes are attracting growing interest in the various fields, and tremendous efforts have been widely made for enhancing the hydrogel electrolyte of flexible devices. However, conventional hydrogel electrolytes generally contain non-degradable and non-renewable polymer matrix materials, inevitably causing waste of resources and environmental pollution, which fundamentally restricts the utilization of hydrogel electrolyte in the aspect of energy storage device during daily use. In this work, a novel flexible hydrogel electrolyte, that can be reducible, recyclable, and reusable (3R), is fabricated through physical and chemistry double crosslinking among carboxylated chitosan, N -methylol acrylamide, N, N' -methylene bisacrylamide, and potassium persulfate, followed by intense uptake of Li 2 SO 4 electrolyte. The hydrogel electrolyte membrane displays high ionic conductivity of 3.52 × 10 -2 S cm -1 , and exhibits 348.92% electrolyte uptake., The flexible quasi-solid supercapacitor assembled with the hydrogel electrolyte shows remarkable electrochemical performance like high capacitance retention of 83% and outstanding energy density of 8.74 Wh kg -1 . Interestingly, the renewable performance of hydrogel electrolyte membrane is observed when the hydrogel electrolyte membrane suffered from heating to cooling cycle, which allows to easily realize multiple regeneration of electrolyte membrane based on the reversible sol-gel transition.

In-Situ Observations of Microscale Ductility in a Quasi-Brittle Bulk Scale Epoxy.

Fiber reinforced composite materials are typically comprised of two phases, i.e., the reinforcing fibers and a surrounding matrix. At a high volume fraction of reinforcing fibers, the matrix is confined to a microscale region in between the fibers (1–200 µm). Although these regions are interconnected, their behavior is likely dominated by their micro-scale. Nevertheless, the characterization of the matrix material (without reinforcing fibers) is usually performed on macroscopic bulk specimens and little is known about the micro-mechanical behavior of polymer matrix materials. Here, we show that the microscale behavior of an epoxy resin typically used in composite production is clearly different from its macroscale behavior. Microscale polymer specimens were produced by drawing microfibers from vitrifying epoxy resin. After curing, tensile tests were performed on a large set of pure epoxy microfiber specimens with diameters ranging from 30 to 400 µm. An extreme ductility was observed for microscale epoxy specimens, while bulk scale epoxy specimens showed brittle behavior. The microsized epoxy specimens had a plastic deformation behavior resulting in a substantially higher ultimate tensile strength (up to 380 MPa) and strain at break (up to 130 %) compared to their bulk counterpart (68 MPa and 8%). Polarized light microscopy confirmed a rearrangement of the internal epoxy network structure during loading, resulting in the plastic deformation of the microscale epoxy. This was further accompanied by in-situ electron microscopy to further determine the deformation behavior of the micro-specimens during tensile loading and make accurate strain measurements using video-extensometry. This work thus provides novel insights on the epoxy material behavior at the confined microscale as present in fiber reinforced composite materials.

Plant-Based Natural Fibre Reinforced Composites: A Review on Fabrication, Properties and Applications

The increasing global environmental concerns and awareness of renewable green resources is continuously expanding the demand for eco-friendly, sustainable and biodegradable natural fibre reinforced composites (NFRCs). Natural fibres already occupy an important place in the composite industry due to their excellent physicochemical and mechanical properties. Natural fibres are biodegradable, biocompatible, eco-friendly and created from renewable resources. Therefore, they are extensively used in place of expensive and non-renewable synthetic fibres, such as glass fibre, carbon fibre and aramid fibre, in many applications. Additionally, the NFRCs are used in automobile, aerospace, personal protective clothing, sports and medical industries as alternatives to the petroleum-based materials. To that end, in the last few decades numerous studies have been carried out on the natural fibre reinforced composites to address the problems associated with the reinforcement fibres, polymer matrix materials and composite fabrication techniques in particular. There are still some drawbacks to the natural fibre reinforced composites (NFRCs)—for example, poor interfacial adhesion between the fibre and the polymer matrix, and poor mechanical properties of the NFRCs due to the hydrophilic nature of the natural fibres. An up-to-date holistic review facilitates a clear understanding of the behaviour of the composites along with the constituent materials. This article intends to review the research carried out on the natural fibre reinforced composites over the last few decades. Furthermore, up-to-date encyclopaedic information about the properties of the NFRCs, major challenges and potential measures to overcome those challenges along with their prospective applications have been exclusively illustrated in this review work. Natural fibres are created from plant, animal and mineral-based sources. The plant-based cellulosic natural fibres are more economical than those of the animal-based fibres. Besides, these pose no health issues, unlike mineral-based fibres. Hence, in this review, the NFRCs fabricated with the plant-based cellulosic fibres are the main focus.

Facilitated transport membranes containing graphene oxide-based nanoplatelets for CO2 separation: Effect of 2D filler properties

Realization of suitable membrane-based technology for efficient CO2 capture to mitigate climate change relies on the development of thin-film composite (TFC) membranes with superior separation performance. Graphene oxide (GO), due to its 2D morphology, intrinsic strength and chemical compatibility, was used as a nanofiller to enhance CO2 separation performance and stability of a facilitated transport membrane. SHPAA (sterically hindered polyallylamine)-based blend matrix was selected as the polymeric matrix material in this work. The high aspect ratio of GO-based fillers, when coupled with optimized coating protocol, resulted in TFC membranes of ultrathin (200 nm) selective layers with the in-plane orientation of nanoplatelets, leading to enhanced separation properties that can be retained for long term. Porous graphene oxide (pGO) was also incorporated as nanofillers, resulting in significantly improved gas permeation at a very low filler loading of 0.2 wt%; A CO2 permeance of up to 607 GPU with a CO2/N2 separation factor of 36 in flat-sheet configuration was documented. Chemical modification of GO with PEG groups was found to further increase the selectivity of the membranes but reduces the CO2 permeance, showing a CO2/N2 separation factor of 90 with a CO2 permeance of 205 GPU. The effect of various 2D nanoplatelets on CO2 transport properties in the membranes of hydrophilic PVA (polyvinyl alcohol) matrix and facilitated transport SHPAA/PVA matrix was elucidated with respect to the nanofiller property and loading.

Microstructure-elastic property relationships in carbon fibers: A nanoindentation study

Carbon fibers with high axial stiffness and strength have been used to reinforce polymer-matrix materials in advanced composites. However, these fibers exhibit large anisotropies in the radial and axial directions. In addition, limited data has been reported on the elastic properties of fibers in other directions than longitudinal and transversal directions, and on the relationship between elastic properties and fiber structures. In this study, we prepared five epoxy composites each containing a different type of carbon fiber and used a nanoindentation method in combination with finite element analysis to investigate five elastic constants of the carbon fibers. The results demonstrate that the crystallite size and the orientation of its graphite-crystal inclusions affect the elastic constants c11, c12, c13 and c33, while the carbon fibers with well-aligned large-sized crystallite possess a large mechanical anisotropy. In contrast, the shear modulus (c44) is less affected by the alignment of the crystallite. Instead, the fibers with larger interlayer spacing of (002) basal planes and large crystallite size exhibit a smaller c44.

FDM-Based 3D Printing of Polymer and Associated Composite: A Review on Mechanical Properties, Defects and Treatments.

Fused deposition modelling (FDM) is one of the fastest-growing additive manufacturing methods used in printing fibre-reinforced composites (FRC). The performances of the resulting printed parts are limited compared to those by other manufacturing methods due to their inherent defects. Hence, the effort to develop treatment methods to overcome these drawbacks has accelerated during the past few years. The main focus of this study is to review the impact of those defects on the mechanical performance of FRC and therefore to discuss the available treatment methods to eliminate or minimize them in order to enhance the functional properties of the printed parts. As FRC is a combination of polymer matrix material and continuous or short reinforcing fibres, this review will thoroughly discuss both thermoplastic polymers and FRCs printed via FDM technology, including the effect of printing parameters such as layer thickness, infill pattern, raster angle and fibre orientation. The most common defects on printed parts, in particular, the void formation, surface roughness and poor bonding between fibre and matrix, are explored. An inclusive discussion on the effectiveness of chemical, laser, heat and ultrasound treatments to minimize these drawbacks is provided by this review.

Investigating the potential use of polymeric materials in the preparation of temporary cosmetic teeth painting veneers

Dental whitening techniques and materials have become one of the most important non-surgical methods used to improve the appearance of teeth and to make them whiter and brighter, as well as to hide blemishes of the teeth. Since the veneer do not last forever and may fail due to fracture or adhesion failure or wrong selection of the appropriate design, removing large thickness of the outer layer of the tooth may make it vulnerable to weakness and long-term failure. This study aims to reach the polymeric combination that enables us to prepare temporary cosmetic teeth painting veneers, and to improve their properties, in order to get the veneers that work to maintain as much tooth structure as possible, hide defects and beautify teeth in the easiest ways and at least costs. The results showed that it is possible to prepare a paint mixture based on cheap and available raw materials consisting of sodium alginate as a polymeric matrix material in this mixture, titanium dioxide as a coloring additive, and calcium chloride solution as a bonding for sodium alginate molecules and improving for their properties. It is recommended to use the fourth combination (sodium alginate 2% + titanium dioxide 4%) immersed in a solution of calcium chloride (11.11% concentration) in the preparation of temporary paints due to its highest chemical stability and having appropriate physical and optical properties that enable them to use possibly as temporary cosmetic teeth painting veneers.

Additive Manufactured Polymer-Bonded Isotropic NdFeB Magnets by Stereolithography and Their Comparison to Fused Filament Fabricated and Selective Laser Sintered Magnets.

Magnetic isotropic NdFeB powder with a spherical morphology is used to 3D print magnets by stereolithography (SLA). Complex magnets with small feature sizes in a superior surface quality can be printed with SLA. The magnetic properties of the 3D printed bonded magnets are investigated and compared with magnets manufactured by fused filament fabrication (FFF), and selective laser sintering (SLS). All methods use the same hard magnetic isotropic NdFeB powder material. FFF and SLA use a polymer matrix material as binder, SLS sinters the powder directly. SLA can print magnets with a remanence of 388 mT and a coercivity of T. A complex magnetic design for speed wheel sensing applications is presented and printed with all methods.

Mehanske lastnosti kompozitnih materialov s polimerno matrico na osnovi celuloze

Mehanske lastnosti kompozitnih materialov s polimerno matrico na osnovi celuloze

Development of high-permeable PSf/PANI-PAMPSA composite membranes with superior rejection performance

Polysulfone is the most popular polymeric matrix material for fabrication of ultrafiltration membrane but suffers from its hydrophobic nature that caused low flux and fouling problems that limits its development and industrial applications. The blending PSf with hydrophilic polymers is an attractive and effective technique to improve the hydrophilicity of membrane. Here poly(2-acrylamido-2-methyl-1-propane sulfonic acid doped polyaniline was synthesized and used as a hydrophilic additive in polysulfone to obtain ultrafiltration range membranes with higher flux. Infrared results supported the increased hydrophilicity of the membranes with PANI-PAMPSA additive which is confirmed by dynamic contact angle analysis results as well. The cross-sectional SEM images revealed that the pristine and blend membranes were asymmetric structured and had dense skin layer, finger-like pores on the top and sponge-like pores underneath the porous support layer. Also, the skin layer of the membrane became thinner and denser with the addition of 0.1 and 0.25 % and thicker with the addition of 0.5 additive ratio. The initial contact angles of P0, P1, P2 and P3 measured as 85, 81, 79 and 72°, respectively. Pure water permeability of the P0, P1, P2 and P3 membranes calculated as 14.0, 17.2, 23.4 and 21.3 L.m−2. h−1. bar−1, respectively. The rejection ratios of the prepared membranes increased from 90.1 (P0) to 95.8 and 98.4 % for P1 and P2 membranes then decreased to 95.2 % for P3 membrane. The rejection results indicated that the prepared membranes can be classified as ultrafiltration membranes with molecular weight cut-offs (MWCOs) lower than 66 kDa g mol−1.

Matching the Directions of Electric Fields from Triboelectric and Ferroelectric Charges in Nanogenerator Devices for Boosted Performance.

SummaryEmbedding additional ferroelectric dipoles in contacting polymer layers is known to enhance the performance of triboelectricnanogenerator (TENG) devices. However, the influence of dipoles formed between the triboelectric surface charges on two contacting ferroelectric films has been ignored in all relevant studies. We demonstrate that proper attention to the alignment of the distinct dipoles present between two contacting surfaces and in composite polymer/BaTiO3 ferroelectric films can lead to up to four times higher energy and power density output compared with cases when dipole arrangement is mismatched. For example, TENG device based on PVAc/BaTiO3 shows energy density increase from 32.4 μJ m−2 to 132.9 μJ m−2 when comparing devices with matched and mismatched dipoles. The presented strategy and understanding of resulting stronger electrostatic induction in the contacting layers enable the development of TENG devices with greatly enhanced properties.

In-situ characterization of the local mechanical behaviour of polymer matrix in 3D carbon fiber composites by cyclic indentation test

In this work, a cyclic indentation test is employed for the in-situ characterisation of the local mechanical properties of a PR520 epoxy resin matrix in a 3D carbon fiber composite. Since the evolution of indentation response with time is studied, the cyclic loading allows to characterise both the elastic and the time dependent, viscoelastic, mechanical response of the material simultaneously. The 3D carbon fiber composite used in this study contains a number of large resin pockets between fiber bundles (mesoscopic scale) with a characteristic dimension ranging from several hundred of micrometers to several millimeters. The mechanical behaviour of the polymer matrix is investigated on the external surface and in volume of the composite and compared with the neat polymer. The instantaneous elastic modulus from reloading, the energy ratio and the residual depth are determined from the cyclic material response and compared through a Student t-test based statistical analysis. Results show that there is at least 95% of probability that the neat and in-situ polymer matrix material belong to different populations. However, this difference is rather small (between 1 and 2.5%) and almost constant with cycles. Moreover, a difference between composite core and surface was measured.

Investigation of thermal behavior of long-distance multilayer pipeline with MicroPCM particles

Long-distance transport of oil and gas in the harsh subsea environment needs reliable pipeline thermal management to prevent wax deposition and hydrate formation. Multilayer pipeline with the PCM-matrix composite material, made of microencapsulated phase change material particles (MicroPCM particles) and polymer matrix material, is proposed as an effective method to meet the flow assurance challenges owing to its thermal energy storage. Compared with the direct applications of PCM, the PCM-matrix composite material can avoid the possible leakage of its liquid phase and decrease the installation difficulty. Theoretical studies are carried out to investigate the proposed multilayer insulation system in a long horizontal pipeline, which embeds an intermediate insulation layer made of the PCM-matrix composite layer. Considering the storage or release of the latent heat and the changes of thermal properties during the phase change process, the global characteristics of the PCM-matrix composite layer is calculated based on the porous media theory. A pseudo-3D model coupled to the finite difference numerical method is developed to simulate the start-up and shut-in transient processes. To address the liquid and solid states of PCM and their interface, the model for the PCM-matrix composite layer is constituted in the form of enthalpy conservation. The influence of the thermal properties of different matrix and PCM materials on the cooldown time is examined. By analyzing the temperature distributions of produced fluid during start-up and shut-in, the current study shows that the use of MicroPCM particles in the composite layer can prolong the maximum cooldown time. In addition, the geometrical parameters, such as the volume fraction of MicroPCM particle and the thickness of the composite layer, are found to also play a role in affecting the extent of the prolongation of the cooldown time.

Vpliv peterokotne in osmerokotne oblike spojev na trajno nihajno trdnost kompozitnih materialov s polimerno matrico

Vpliv peterokotne in osmerokotne oblike spojev na trajno nihajno trdnost kompozitnih materialov s polimerno matrico

Polyethylene Nanocomposites with Ni, Co, and Fe Carbon‐Based Magnetic Fillers

In the present study, the effect of Ni, Co, and Fe carbon‐based magnetic fillers (Ni‐C, Co‐C, and Fe‐C) was investigated on the magnetic, mechanical, thermal, and morphological properties of polyethylene nanocomposites. The in situ polymerization technique was used to prepare nanocomposites of polyethylene from the ethylene monomer introducing small amounts of filler ranging from 1 to 2 wt.%. The metal‐carbonized fillers were obtained by pyrolysis of wood sawdust activated by Ni, Co, or Fe salts. X‐ray diffraction showed that the fillers were of nanometric size. Thermogravimetric analysis was executed to investigate the thermal strength of the materials as well as to calculate the metal content in the carbon‐based fillers. The onset degradation temperature showed an enhancement of 17°C, whereas the maximum degradation temperatures increased 4°C with the introduction of the filler. Differential scanning calorimetry indicated an improvement of 3°C in crystallization temperature, whereas the melting temperature remained unchanged compared to neat polyethylene. The filler was shown to increase the modulus of elasticity of the nanocomposites. The addition of 1.0 wt.% of the metal‐carbonized material in the diamagnetic polymer matrix resulted in a thermoplastic nanocomposite with ferromagnetic behavior. POLYM. ENG. SCI., 60:988–995, 2020. © 2020 Society of Plastics Engineers

On the identification of diffuso-mechanical properties of polymer matrix materials based on the use of plates with asymmetric moisture concentration field

The aim of the paper is to investigate the possibility to identify the moisture affected mechanical properties and the coefficient of moisture expansion of polymer matrix materials using plates subject to asymmetric concentration field. The study is performed on samples with thin plate configuration using a weakly coupled diffuso-mechanical model: 1D Fick’s diffusion model and 2D plane stress hygroelastic model. Because of the intensity of the deflections caused by the asymmetry of the concentration field, the use of a model taking into account geometrical non-linearities is discussed. The identification is performed according to a constant and linear dependence of Young’s modulus on moisture content. It is shown that diffuso-mechanical properties and the coefficient of moisture expansion can be simultaneously identified by using geometrically linear and non-linear approaches.

Luminescent Hybrid Materials Based on Polymers of Poly(Alpha-Fluoroacrylates) Doped with Tb(III) Complex

This study is devoted to the development of efficient luminescent hybrid materials excited by UV radiation and featuring narrow luminescence lines as well as light, humidity, and temperature resistance. As a luminescent material, a terbium ion coordination compound introduced into the matrix of an organofluorine polymer is used. It has been shown that efficient excitation transfer to electronic levels of the terbium ion can be achieved by proper ligand selection. The polymer matrix material does not affect the luminescence properties of the Tb(III) coordination compound.

Determination of transverse and shear moduli of single carbon fibres

Carbon fibres are extensively used for their high specific mechanical properties. Exploiting their high axial stiffness and strength, they are employed to reinforce polymer matrix materials in advanced composites. However, carbon fibres are not isotropic. Data of the elastic properties in the other directions of the fibres are still largely unknown. Furthermore, standardised methods to characterise these properties are lacking. In the present work, we propose a methodology to determine the transverse and shear moduli of single carbon fibres. An experimental procedure is developed to fabricate high-quality, flat fibre cross-sections in both longitudinal and transverse directions using Focused Ion Beam, which gives full control of the specimen geometry. Indentation modulus on those surfaces are obtained using both Atomic Force Microscopy (AFM) and nanoindentation tests. Hysteresis was found to occur in the nanoindentation tests. The hysteresis response was due to nano-buckling and reversible shear deformation of the carbon crystals. For this reason, indentation tests using AFM is recommended. From the AFM indentation tests the transverse and shear moduli of three different carbon fibres (IMS65, T800 and M60J) are successfully determined.