Production Of Polymer Composites Research Articles

Mechanical assessment for enhancing hybrid composite performance through silane treatment using RSM and ANN

The study utilized Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) to identify the optimal combination of three key factors for producing polymer composites: nanoparticle percentage, silane concentration, and silane dipping duration. RSM and Analysis of Variance (ANOVA) were applied to explore the relationships between these variables and their effects on composite properties. Additionally, the ANN was used to analyze multiple factors, revealing a strong correlation between predicted and observed results. The findings highlighted that silane treatment was the most influential factor in enhancing the composite's flexural strength. Fiber-related properties, particularly the duration of silane dipping, significantly impacted both flexural strength and hardness. Nanoparticles further strengthened the fiber matrix by encouraging effective agglomeration. The ANN demonstrated 95% accuracy in predicting flexural strength and hardness, and its predictions were validated by comparing them with experimental data and the regression model's outcomes. Silane concentration also notably influenced flexural properties. The RSM analysis identified the optimal combination for maximizing flexural strength and hardness: 5% nanoparticles, 10% silane concentration, and a 20-minute silane dipping time.

Aligning halloysite nanotubes in elastomer toward flexible film with enhanced dielectric constant

Naturally occurring halloysite nanotubes (HNTs) are considered electrically insulating counterparts of carbon nanotubes, and they are always randomly distributed in the reported polymer composites. With the recent optimization in advanced processing techniques for the production of muti-functional polymer composites, efficiently aligning micro-/nano-fillers in polymer matrix have been available. Here, we fabricate such aligned HNTs-silicon elastomer (PDMS) composites enabled by alternating current (AC) electric field driven alignment and report that at 7 wt% HNTs loading, the dielectric constant of aligned HNTs/PDMS composite film is almost 150 % (8.46 vs 5.71) higher than that of unaligned one at measurement frequency of 1 kHz. It is also observed that such high loading of nanoparticles brings negligible increase in dielectric loss and does not compromise much of the flexibility. This work provides a renewed understanding of the potential of aligning fillers in polymer matrix, allowing the proper utilization of the high polarization and extremely low dielectric loss predicted for HNTs in the fabrication of polymer composite dielectrics.

Enhanced properties of low-density polyethylene composites reinforced with Bridelia ferruginea fibers: effect of low temperature fiber acetylation

In this study, lignocellulosic fibres were extracted from Bridelia ferruginea (BF), a shrub which can be found in sub-Saharan Africa with a view to probing the potential application of the fibres. The chemical properties of the BF were chemically modified by acetylation to evaluate the potential applications of the fibre reinforced polymer composites. The unacetylated and acetylated fibres were characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Thermogravimetric Analysis (TGA) to compare thermal and crystallographic properties after acetylation over different lengths of time. The acetylated fibres with the most promising properties were used for the fabrication of a polymeric composite. The mechanical properties of the fibre-reinforced polymer composites were studied by hardness and dynamic mechanical measurements. Four types of polymeric samples were prepared for the mechanical measurements: unreinforced polymer (Control) polyester, ATBF/LDPE, ACEBF3/LDPE, ACEBF/LDPE. The SEM micrographs revealed that acetylation led to defibrillation. FTIR peaks at 1250 cm−1 and 1371 cm−1 confirmed that acetylation had occurred. The fibres possessed high crystallinity index of 75% which reduced as time of acetylation increased. Acetylation at mild conditions of 70 °C for 3 h did not result in significant damage to the fibres. For the hardness measurements, the values of the micro-hardness of the composite samples increased from 0.20 GPa to 0.29 GPa. The acetylated fibres tend to further resist deformation due to its dispersion in the polymer matrix providing a stronger cross-linking effect. The properties unearthed show that BF appears to be a promising raw material for the production of polymer composites.

An experimental study on the wear performance of 3D printed polylactic acid and carbon fiber reinforced polylactic acid parts: Effect of infill rate and water absorption time

AbstractRapid prototyping, also known as additive manufacturing, is a nascent technology that is gaining traction in the context of environmental concerns and waste reduction, as well as the growing trend towards customized design. The additive manufacturing method, which has applications in diverse fields such as aviation, architecture, biomedical and automotive engineering, has also begun to be utilized in the construction of yachts and yacht hulls within the maritime industry. In this experimental study, the influences of sea water on polylactic acid (PLA) and carbon fiber reinforced polylactic acid (PLA/CF) parts manufactured at different infill rates (20%, 60% and 100%) were investigated. The parts were exposed to sea water for three different periods (1, 5, and 10 days) and subsequently subjected to wear tests. The dimensional accuracy, surface roughness, hardness, water absorption, volume loss, and friction coefficient of parts were measured and calculated. Additionally, the worn surfaces of the parts were investigated using field emission scanning electron microscope (FESEM) images. The findings indicate that PLA and PLA/CF parts can be produced with high dimensional accuracy. Furthermore, it can be reported that the water absorption of PLA/CF parts increased, particularly with an increase in the infill rate, while the volume loss decreased. Obtained results indicate the necessity of optimizing the 3D printing parameters and the relationship between the ambient conditions and the wear performance of the 3D printed parts.Highlights 3D printing is a highly promising method for the production of polymer composites. A pioneering study into the effect of infill rate and water absorption on the wear performance. Coefficient of friction values of PLA and PLA/CF parts ranged between 0.37 and 0.75. PLA/CF mostly exhibited higher volume loss than PLA with water absorption. Volume loss declines with a raise in the infill rate from 20% to 100%.

Thermal Weathering of 3D-Printed Lunar Regolith Simulant Composites.

The production of lunar regolith composites is a promising venture, especially when enabled by extrusion-based additive manufacturing techniques such as direct ink write. However, both three-dimensional (3D) printing production and usage of polymer composites containing regolish on the lunar surface are challenges due to harsh environmental conditions such as severe thermal cycling. While thermal degradation in polymer composites under thermal cycling has been studied, there is limited understanding of how polymer properties impact the mechanical performance of lunar regolith composites when both printing and usage are carried out under extreme thermal conditions. Here, we aim to bridge that gap through the creation of composites containing a lunar Highlands regolith simulant suspended in an ultraviolet (UV) curable binder, which were printed at -30 °C and thermally cycled between weekly lunar day (127 °C) and weekly night (-190 °C) temperatures. We validate that thermal stresses cause both physical and chemical degradation since the regolith simulant composites become stiffer, more porous, and show yellowing after exposure to thermal cycling. Moreover, we indicate that chemical degradation mechanisms seem to compete with residual polymerization in certain formulations. We attribute this phenomenon to partial crystallization of monomer species during printing at -30 °C, resulting in low vinyl bond conversion during initial curing. The results presented here shed light on the intricate interplay between thermal stresses, uncured polymer properties, and degradation mechanisms, which can help guide future use cases of regolith composites for lunar infrastructure needs.

Additive manufacturing and mechanical performance of short fiber reinforced PEEK (polyether ether ketone) thermoplastic composites in a vacuum environment

Short fiber reinforced thermoplastic composites (SFRTC) have gained popularity in the material extrusion (MEX) method, which is an additive manufacturing (AM) technology, allowing for the simpler and more cost-effective production of polymer composites. However, parts produced using MEX 3D printing technology often exhibit poor mechanical properties and surface quality compared to products manufactured using injection molding, which is one of the main disadvantages of this method. Various methods are used to overcome these challenges, such as production in a vacuum environment, heat-based processes, ultrasonic vibrations, and others. The objective of this study was to achieve parts with lower porosity and improved mechanical properties when printed in a vacuum environment compared to an atmospheric environment. Additionally, an investigation into the optimization of printing parameters was conducted to determine the parameters that yield the highest mechanical properties. For this purpose, SFRTC parts were printed at different vacuum levels (0.5, 10, 100 mbar), and they were subjected to flexural tests to determine their mechanical properties. The results showed that the flexural stress and elastic modulus of the samples produced in a 0.5 mbar vacuum environment increased by 79.75% and 39.41%, respectively, compared to samples produced in an atmospheric environment. Furthermore, the cross-sectional images of the samples were examined using an optical microscope, revealing the lowest porosity in the samples printed in 0.5 mbar vacuum environment.

Production of Natural Straw-Derived Sustainable Polymer Composites for a Circular Agro-Economy

Production of Natural Straw-Derived Sustainable Polymer Composites for a Circular Agro-Economy

QUALITY CONTROL METHODS AND MODELS OF POLYMER COMPOSITE MATERIALS

This article analyzes the traditional and modern methods of demolition control applied to structures made of polymer composite materials. Polymer composite materials are designed to ensure the strength of structures with a minimum mass, not subject to corrosion, etc. as there are advantages. But such materials require a special approach in the preparation and creation and the application of new methods, tools and solutions. This is due to the fact that there are many different types of polymer composite materials. Therefore, the development of criteria for the analysis of quality control methods and models, reliability forecasting in the technology of manufacturing products from polymer composite materials is an urgent issue. The authors give recommendations for the selection of methods for a complete assessment of the quality of compositional materials. The analysis of effective methods of quality control and forecasting of reliability of polymer composite materials was carried out. For this purpose, factors for the choice of the method and reliability prediction have been identified, taking into account its complexity for controlling polymer composite materials. Models for controlling polymer composite materials and products made on its basis were selected and on their basis the effectiveness of the application of low-frequency ultrasonic devices at the separation boundaries of controlled environments was determined.

Synthesis of stable fluorescent ethylene-vinyl acetate copolymers based on in-situ grafted rare-earth organic complexes and antioxidants through transesterification

The synthesis and application of rare earth organic complexes (REOCs) are gaining attention due to their advantages including low excitation thresholds and high luminescence efficiencies. However, their integration as functional fillers in polymer matrices is constrained by challenges related to poor dispersion and limited stability. This study introduces a novel method for synthesizing stable fluorescent polymers by co-grafting europium (Eu) complexes and the antioxidant 3,9-bis-{1,1-dimethyl-2[β-(3-tert-butyl-4-hydroxy-5-methylphenyl-)propionyloxy]ethyl}-2,4,8,10-tetraoxaspiro[5.5]-undecane (AO-80) onto an ethylene-vinyl acetate (EVA) matrix through an in-situ synchronous grafting strategy, aiming to address these dual challenges of poor dispersion and rapid aging. In this study, Eu complexes characterized by low excitation thresholds and high hexahydrate (EuCl3) and selected ligands - 1,10-phenanthroline (Phen), alpha-thienyl trifluoroacetone (HTTA), and 4-acetoxybenzoic acid (4-ABA). Through transesterifications, the Eu complexes were successfully grafted onto the EVA chain, achieving a uniform dispersion within the EVA matrix to form fluorescent polymers. Furthermore, the incorporation of antioxidant AO-80 as a radical scavenger can significantly mitigate fluorescence attenuation. Through detailed exploration of transesterifications under various conditions, optimal grafting rates of 11.34% for EVA with Eu complexes and 22.87% for EVA with AO-80 were achieved. The synthesized fluorescent polymers of EVA synchronously grafted with Eu complexes and AO-80 have been proven to obtain markedly improved fluorescence stability and aging resistance by outdoor aging tests. Our findings not only validate the in-situ reaction grafting method as an efficient strategy for producing polymer composites with excellent fluorescence stability but also pave the way for future research aimed at overcoming the limitations of REOCs in photovoltaic and agricultural applications.

Valorization of bean agricultural wastes for the production of polymeric composites

Valorization of bean agricultural wastes for the production of polymeric composites

Valorization of bean agricultural wastes for the production of polymeric composites

Valorization of bean agricultural wastes for the production of polymeric composites

Influence of Biogenic Material Content on the Biodegradability of Styrene-Butadiene Composites with Incorporated Chlorella vulgaris Biomass.

Bio-fillers are intensively studied for advanced polymer composite circular design and production. In this context, the algal biomass may be considered an important and relatively low-cost resource, when harvested as a by-product from wastewater treatment plants. The biomass of the algal species Chlorella vulgaris is frequently used in this type of environmental process, and its macro constituents' composition ranges from around 15-25% carbohydrates, 10-20% lipids, and 50-60% proteins. Poly (styrene-butadiene-styrene) (SBS) copolymers have a matrix composed of glassy polystyrene domains connected by flexible polybutadiene segments. Although the physical-mechanical properties of SBS copolymers recommend them for many industrial applications, they have the drawback of low biodegradability. This study aimed to assess the aerobic biodegradability of polymer composites by integrating biomass from Chlorella vulgaris at varying mass percentages of 5, 10, and 20% into SBS copolymer composites. Biodegradation tests were conducted under industrial composting conditions (58 °C and 50% relative humidity) for 180 days. The biodegradability of materials was evaluated by measuring the CO2 produced in each vessel during the study period. Potential correlations between the amount of carbon dioxide released and the percentage of biomass added to the polymer matrix were examined. Structural and morphological changes were assessed using Fourier Transform infrared spectroscopy (FTIR), thermal analysis (DSC), and scanning electron microscopy (SEM). Physical and chemical testing revealed a decrease in sample density after the industrial composting test, along with noticeable changes in melt flow index (MFI). The observed physical and chemical changes, coupled with FTIR, SEM, and DSC data, indicate increased cross-linking and higher porosity in biodegraded polymer structures with higher biomass content. This behavior is likely due to the formation of cross-linked connections between polymer chains and polypeptide chains resulting from protein degradation, enhancing connections between polystyrene units facilitated by peptide bonds with the benzene units of the styrene blocks within the polymer matrix.

Enhancing Thermal Conductivity in Polymer Composites through Molding-Assisted Orientation of Boron Nitride.

Incrementing thermal conductivity in polymer composites through the incorporation of inorganic thermally conductive fillers is typically constrained by the requirement of high filler content. This necessity often complicates processing and adversely affects mechanical properties. This study presents the fabrication of a polystyrene (PS)/boron nitride (BN) composite exhibiting elevated thermal conductivity with a modest 10 wt% BN content, achieved through optimized compression molding. Adjustments to molding parameters, including molding-cycle numbers, temperature, and pressure, were explored. The molding process, conducted above the glass transition temperature of PS, facilitated orientational alignment of BN within the PS matrix predominantly in the in-plane direction. This orientation, achieved at low filler loading, resulted in a threefold enhancement of thermal conductivity following a single molding time. Furthermore, the in-plane alignment of BN within the PS matrix was found to intensify with increased molding time and pressure, markedly boosting the in-plane thermal conductivity of the PS/BN molded composites. Within the range of molding parameters examined, the highest thermal conductivity (1.6 W/m·K) was observed in PS/BN composites subjected to five molding cycles at 140 °C and 10 MPa, without compromising mechanical properties. This study suggests that compression molding, which allows low filler content and straightforward operation, offers a viable approach for the mass production of polymer composites with superior thermal conductivity.

Self-catalysed frontal polymerisation enables fast and low-energy processing of fibre reinforced polymer composites

Frontal polymerisation has the potential to bring unprecedented reductions in energy demand and process time to produce fibre reinforced polymer composites. Production of epoxy-based fibre reinforced polymer parts with high fibre volume content, commonly encountered in industry, is however hindered by the heat sink created by the fibres and the mould, overcoming the heat output of the chemical reaction, thus preventing front propagation. We propose a novel self-catalysed frontal polymerisation manufacturing method based on the integration of thin resin channels in thermal contact with the composite stack as a strategy for low-energy production of high fibre volume fraction polymer composites without the need for a continuous energy input. Frontal polymerisation inside the resin channel proceeds faster and preheats the fabric stack, thus catalysing the process. Parts with up to 60% fibre content are successfully produced independently of the sample thickness. Fillers added within the resin channels provide means to tailor the frontal polymerisation process kinetics. The parts have a significantly higher glass transition temperature than those produced in a conventional oven, and comparable mechanical properties while energy consumption is reduced by over 99.5%.

Optimization of the magnetostrictional molding composites structure

The paper presents the methodology of multi-criteria synthesis of magnetostrictive cast composites with high physical-mechanical and anti-corrosive properties. The synthesis of composites is realized by solving nonlinear mathematical programming tasks sequentially. The quality of the modeling was evaluated using the composite quality functional. The numerical methods for solving the optimization problem of the target function of kinetic processes are based on the construction of Pareto sets, penalty functions of Arrow-Hurwitz, and the method of equal estimate regions. The necessary and sufficient criteria for forming optimal recipe-technological parameters were established, allowing to obtain composites with specified structure and properties. The proposed methods were tested in the development of a practical technology for producing polymer composites with magnetostrictive properties.

APPROACH TO THE SELECTION OF TYPES OF POLYMER-COMPOSITE PIPES FOR FIELD PIPELINES

The work is devoted to the use of polymer-composite pipes (PCP) in the field conditions of the oil and gas industry. Based on a review of existing types of non-metallic pipes of various designs used for the construction of field pipelines, a knowledge base of current technological solutions has been formed and their advantages and disadvantages have been identified. A catalog of technological solutions for field pipelines has been developed, which includes a description of the designs of PCP with their technical characteristics necessary for the design and operation of field pipelines. An applicability matrix has been developed that allows one to determine suitable types and designs of PCP according to technical principles for pipeline construction under certain conditions. The selection criteria are pipe sizes, operating parameters (pressure and temperature), service life, pumped media, purpose of the pipeline and resistance to aggressive media (CO2, H2S). If the PCP meets the specified conditions, this product is included in the matrix for further use in the construction and operation of the pipeline. However, in order to be able to equip fields with pipelines made of polymer-composite materials, it is necessary that solutions made from PCP are not only technically sound, but also economically justified in comparison with steel pipes. One of the main results of this study is the development of a feasibility study methodology (FS) of applicability, which allows us to determine the most effective option for the design and operation of pipelines made of PCP based on a comparison of economic indicators. The methodology was based on a comparison of the cost of steel and polymer-composite products, the cost of construction and installation work and the speed of their implementation, the cost of maintaining pipelines during operation, as well as the costs associated with pipe failures - to eliminate their consequences.
 As part of the study, the accident rate of steel and polymer-composite pipes was also analyzed and studied, on the basis of which a methodology for predicting accident rates for PCP was created.
 Finally, conclusions are made about the possibility of using the developed tools in the oil and gas industry.

The Improvement of the Tribological Behaviour of Chemically Treated Abaca Fibre-Reinforced Polymer Composites.

Abaca fibres that have excellent mechanical properties are widely applied in the production and preparation of eco-friendly polymer composites as reinforcement materials. However, the weak interfacial bonding property of the abaca fibre and composite matrix limits the further extended application of abaca fibre-reinforced polymer composites. In this research, the findings demonstrate that, compared to raw abaca fibres, the interfacial shear strength (IFSS) value between the treated fibre and matrix is improved by 32% to 86%. Moreover, chemically treated abaca fibres could not only improve the wear resistance of the polymer composites, but also could promote the formation of primary and secondary plateaus. The best wear resistance behaviour was demonstrated by the sample with abaca fibres treated with 3% NaOH and 5% silane solutions, which had a maximum reduction in the sum wear rate of 28.44%. This research will provide detail on theoretical guidance and technical support for the development of eco-friendly natural fibre-reinforced polymer composites.

ИССЛЕДОВАНИЕ РЕОЛОГИЧЕСКИХ СВОЙСТВ РАСТВОРОВ ПОЛИВИНИЛБУТИРАЛЯ В СМЕСИ МОНОМЕРОВ ТРИ(1-МЕТАКРИЛОКСИ-3-ХЛОРПРОПОКСИ-2-)ФОСФАТА И ГЛИЦИДИЛМЕТАКРИЛАТА

The method of rotation viscometry is used to study the rheological properties of various proportions of polyvinyl butyral solutions in tris(1-methacryloxy-3-chloropropoxy-2-) phosphate and glycidyl methacrylate. It is established that the dynamic viscosity of polymer solutions ranges from 101 to 3995 mPa∙s as a function of temperature and different proportions of the monomers.The polymer solution flow complies with a two-phase mechanical model comprising viscous as well as plastic and creep deformation. The analyzed polymers can be used as binders to produce polymer composites by vacuum and thermal vacuum infusion.

Ethiopian Bamboo Fiber Aging Process and Reinforcement: Advancing Mechanical Properties of Bamboo Fiber-Epoxy Composites for Automobile Applications

The purpose of this paper is to evaluate the properties of Ethiopian bamboo fibre polymer composites as headliners in the automobile industry. Bamboo fibres are developed using the roll milling technique, and bamboo fibre epoxy composites (BFEPCS) are developed using a compression mould and a hot press machine. The mechanical properties are measured based on the recommended procedure of the ASTM. In total, 40% of the volume fraction of fibres is used to produce polymer composites. An accurate evaluation of its mechanical properties is thus critical for predicting its behaviour during a vehicle’s interior impact assessment. Conventional headliner materials are heavier, non-biodegradable, expensive, and non-sustainable during processing compared to the currently researched materials. Three representatives of bamboo plants are harvested in three regions of bamboo species, three groups of ages, and two harvesting months. Two-year-old bamboo fibres have the highest mechanical properties of all ages, and November has a higher mechanical properties compared to February. Inji-bara and Kom-bolcha have the highest and lowest mechanical properties, respectively. BFEPCs have high mechanical properties compared to BFPPCs. The mechanical properties of the current research findings have higher measured values compared to Jute felt PU, CFPU, GFMPU, BFPP, BFEP, PP foam, and TPU. The flexural strength of BFPCs has higher properties compared to their tensile strength. Ethiopian bamboo fibres and their polymer composites have the best mechanical properties for the composite industry, which is used for headliner materials in the automobile industry, compared to conventional headliner materials.

Coordination Compound (2,3,5-Triphenyltetrazolium)2[CuBr4] as Catalyst for the Curing Process of Epoxy Vinyl Ester Binders.

This article presents a study on the synthesis and catalytic properties of copper complex (TPhTz)2[CuBr4] (here TPhTz is 2,3,5-triphenyltetrazolium). The obtained complex was characterized by various spectroscopic methods. The catalytic properties of the complex were evaluated in the curing of an epoxy vinyl ester system and their effectiveness was compared with that of cobalt octoate (its synonyms are known as Co(Oct)2, cobalt(II) 2-ethylhexanoate, cobalt isocaprylate, etc.). The catalyst was added at an amount of 2 w.%. The results showed that a 8 w.% solution of the complex provides catalytic properties with an activation energy of 54.7 kJ/mol, which is 25.2 kJ/mol higher than a standard curing system with Co(Oct)2. Thus, the solution of (TPhTz)2[CuBr4] in THF/DMSO accelerates the initiator decay process at room temperature, but for a longer time. The authors suggest that the curing mechanism may be accelerated by the appearance of (TPhTz)2[CuIBr3] and free bromine in the system. A strength test of fiberglass-reinforced plastic revealed that the addition of this complex did not lead to a decrease in flexural strength and hardness. Thus, use of the complex allowed for the production of polymer composite products using vacuum-assisted resin transfer molding where an extended injection time was needed.