Thermoplastic Polymer Materials Research Articles

Pemanfaatan Limbah High Density Polyetylene (HDPE) Geomembrane Sebagai Campuran Beton Normal

High-Density Polyethylene (HDPE) is a thermoplastic polymer material processed by the heating process of petroleum. One processed product is geomembrane sheets, commonly used to construct ponds in geothermal areas. This Final Project researched High-Density Polyethylene geomembrane waste as an additional material mixed into ordinary or everyday concrete mixtures with fc' = 25 MPa quality. The added waste material from the geomembrane (HDPE) is 0.5 x 0.5 cm and has been cut or chopped with a particular machine. High-density polyethylene (HDPE) content is included in the mixture in regular concrete with a volume composition of 0.00%, 0.25%, 0.50%, 0.75%, and 1.00%. The method for calculating the composition of the concrete mixture uses the American Concrete Institute (ACI) standard. The results showed that the most optimum value for obtaining the compressive strength of concrete fc' 25 MPa with the highest value of split tensile strength (3.54 MPa) was a mixture with 0.50% chopped geomembrane (HDPE). Based on these results, waste in geothermal areas is expected to be reduced by using concrete and a mixture of chopped geomembrane (HDPE).

A treatise on mechanical properties of natural and synthetic fibre reinforced hybrid polymer composites

Hybrid composites have proved to be a potential material attracting large scale attention for applications such as in construction, automobiles, aerospace and locomotives. In this article, a treatise on the hybrid composites types, their diversity of properties, the effect of various fibre surface treatments on mechanical properties of natural fibres and possible natural and synthetic fibre combinations for a variety of applications is presented. The mechanical characterization (tensile, flexural and impact) of different combinations of natural and synthetic fibres in thermoplastic or thermoset polymer matrices along with the critical issues is also showcased. Although the importance of hybrid composites, mechanical properties and their applications are already available in the literature, enhancing damage tolerance and impact resistance has not been duly focused by the research community.

Valorization of bio‐calcium carbonate based Chamelea gallina shell waste fillers in shape memory polymer composites

AbstractIn recent years, the focus has been on the use of calcium carbonate‐based seashell wastes in the production of new thermoplastic and thermoset polymer materials, paving the way for their use as biofillers in polymeric composites. In this study, it is aimed to obtain a new polymeric composite material by doping Chamelea gallina shells, on polylactic acid (PLA)/polyethylene glycol (PEG) blend. Structural characterization of the obtained PLA/PEG blend/C. gallina composite films was performed with attenuated total reflection infrared spectroscopy (ATR‐IR). When the thermal properties of composite materials were examined by thermogravimetric analysis (TGA), it was determined that the thermal stability of polymeric composites increased with the addition of C. gallina. SEM images showed that the polymer blend films, which appeared to have a porous structure, filled the pores with increasing C. gallina ratio. It was observed that the biodegradability of PLA/PEG blend composite films decreased with increasing C. gallina shells addition. However, C. gallina had a positive effect on the swelling and water absorption capacities of polymeric composites. The increase in tensile strength and elongation at break values of PLA/PEG blend/C. gallina composite films with increasing C. gallina means that the mechanical properties of the polymer are improved.

The Effect of Using Ceramic Cutting Tools for Turning Thermoplastic Polymer Materials

The Effect of Using Ceramic Cutting Tools for Turning Thermoplastic Polymer Materials

Influence of low-melting-point SnPb alloy powder on the performance of polylactic acid in injection molding

Polylactic acid is a thermoplastic polymer material known for its excellent biocompatibility, although it suffers from subpar rheological and mechanical properties. In this study, an investigation was carried out to assess how low filling degree, low melting point tin–lead alloy powder affects the mechanical and rheological properties of the PLA matrix during the injection molding process. The results of the study indicated that SnPb alloy powder could effectively enhance the melt flow of PLA during processing and serve as a solid filler after molding, resulting in a significant improvement of the material’s mechanical properties.

ASSESSMENT OF THE POSSIBILITY OF USING POLYMERS IN THE BODIES OF PROMISING LAUNCH VEHICLES BASED ON THE HEAT RESISTANCE FACTOR

One of the possible ways to solve the problem of quick and low-cost payloads to low Earth orbits is the creation of ultralight rockets that use new construction materials, in particular, synthetic polymers. A promising approach to creating a launch vehicle of this type is the concept of a burnt rocket, the body of which is made of thermoplastic polymer materials. At the same time, the practical implementa- tion of such a launch vehicle requires additional research, in particular, the possible process of premature destruction of the structure due to aerodynamic heating. In this work, the heat resistance of polymer bodies of a new type of ultralight launch vehicles during flight in the atmospheric part of the trajectory was evaluated. For mathematical modeling of heating processes, we used the results of experimental studies of the thermodynamics of polyethylene and polypropylene during heating. These results allowed us to propose a mathematical model for calculating the process of heating polymer shells. The dynamics of the temperature fields during movement along the given trajectory of the launch vehicle in the atmospheric stage have been determined. It was established that under the given trajectories, both considered materials satisfy the conditions of heat resistance. The influence of temperature on the reduction of the strength characteristics of polymer bodies is shown, and the necessary thicknesses of the walls of the body shells, which should prevent deformation of the structure during aerodynamic heating, are determined. So, for the first time, the possibility of making rocket bodies from thermoplastic polymer materials has been theoretically substantiated.

The effect of using ceramic cutting tools in turning thermoplastic polymer materials

The effectiveness of turning of polymeric materials with cutting ceramics is evaluated. It is experimentally proven that the turning of caprolon and fluoroplastic using a cutting insert made of КНТ16 cermet provides a higher quality of the machined surface. The roughness parameters of the surface machined with cermet cutting inserts are lower than when turning with ВК8 tungsten-cobalt alloy inserts, and a different type of chip is also formed. Keywords: thermoplastic, turning, cutting tool, tungsten-cobalt hard alloy, cutting ceramic, cermet, chip formation, roughness. erenkov@list.ru

A Comprehensive Mechanical Examination of ABS and ABS-like Polymers Additively Manufactured by Material Extrusion and Vat Photopolymerization Processes.

Additive manufacturing technologies have developed rapidly in recent decades, pushing the limits of known manufacturing processes. The need to study the properties of the different materials used for these processes comprehensively and in detail has become a primary goal in order to get the best out of the manufacturing itself. The widely used thermoplastic polymer material acrylonitrile butadiene styrene (ABS) was selected in the form of both filaments and ABS-like resins to investigate and compare the mechanical properties through a series of different tests. ABS-like resin material is commercially available, but it is not a sufficiently mechanically studied form of the material, which leads to the rather limited literature. Considering that ABS resin is a declared material that behaves like the ABS filament but in a different form, the objective of this study was to compare these two commercially available materials printed with three different 3D printers, namely Fused Deposition Modelling (FDM), Stereolithography (SLA) and Digital Light Processing (DLP). A total of 45 test specimens with geometries and test protocols conforming to the relevant standards were subjected to a series of tensile, three-point bending and compression tests to determine their mechanical properties. Characterization also included evaluation of morphology with 2D and 3D microscopy, dimensional accuracy of 3D scans, and Shore A hardness of each material and 3D printing process. Tensile testing results have shown that FDM toughness is 40% of the value for DLP. FDM elongation at break is 37% of DLP, while ultimate tensile stress for SLA is 27% higher than FDM value. Elastic modulus for FDM and SLA coincide. Flexure testing results indicate that value of DLP flexural modulus is 54% of the FDM value. SLA strain value is 59% of FDM, and DLP ultimate flexure stress is 77% of the value for FDM. Compression test results imply that FDM specimens absorb at least twice as much energy as vat polymerized specimens. Strain at break for SLA is 72% and strain at ultimate stress is 60% of FDM values. FDM yield stress is 32% higher than DLP value. SLA ultimate compressive stress is half of FDM, while value for DLP compressive modulus is 69% of the FDM value. The results obtained are beneficial and give a more comprehensive picture of the behavior of the ABS polymers used in different forms and different AM processes.

Analysis of the mechanical properties of the single layered braid reinforced thermoplastic pipe (BRTP) for oil & gas industries

Reinforced thermoplastic pipes (RTPs) are instantly being broadly scrutinized as a feasible surrogate for metallic pipes due to their superior corrosion resistance, low weight, and low maintenance worth, they have three primary layers inner, outer, and reinforcement. Process parameters for manufacturing reinforced layers are critically essential to enhancing the mechanical performance of RTPs. However, limited comparative research on the impact of braiding parameters on RTP’s mechanical characteristics appears to be publicly available. Therefore, this study examines how these variables affect the mechanical characteristics of braid RTP. This new class of braid RTP is constructed of an HDPE liner pipe, over-wrapped with a single braid layer of resin glass fiber. L9 Taguchi orthogonal array design for experiments was used to create specimens. Furthermore, specimens were subjected to tensile and compression to assess their mechanical properties. Epoxy and ±75 were the most promising parameters in achieving the highest number of tensile and compression properties among choices of thermoplastic polymer matrices and braid angles, respectively. ANOVA suggested that both parameters are significant and significantly impact the mechanical properties of the prototype braid RTP. Also, A1B3 is considered the best combination for producing braid RTP with higher mechanical performance; no notable interaction among factors was found.

Construction and Compensation of a Dimensional Accuracy Model of a Powder Bed via Laser Sintering.

In the laser sintering (LS) printing process, a printed part is formed by sintering layer-by-layer on the powder bed. Thus, it is necessary to consider the dimensional accuracy of the laser-sintered powder bed as an important evaluation index. In this paper, a generalized powder bed-size accuracy compensation model is proposed for non-crystalline thermoplastic polymer materials. Taking polyethersulfone (PES) material as an example, the main factors influencing powder bed dimensional accuracy during LS printing are modeled and analyzed experimentally in this study, including four important factors: laser reference deviation, temperature deviation, density deviation, and secondary sintering deviation. In this study, CX_A200 LS equipment is used for prototyping and verification, a 3D scanning method is used to measure the printed parts, and the measurement results are digitally compared and analyzed. On this basis, the relationship of each influencing factor in the proposed compensation model is determined experimentally, and the experimental results demonstrate that the proposed compensation model is approximately 95% effective in terms of correcting the deviation of powder bed dimensional accuracy.

Role of Rheology in Morphology Development and Advanced Processing of Thermoplastic Polymer Materials: A Review.

This review presents fundamental knowledge and recent advances pertaining to research on the role of rheology in polymer processing, highlights the knowledge gap between the function of rheology in various processing operations and the importance of rheology in the development, characterization, and assessment of the morphologies of polymeric materials, and offers ideas for enhancing the processabilities of polymeric materials in advanced processing operations. Rheology plays a crucial role in the morphological evolution of polymer blends and composites, influencing the type of morphology in the case of blends and the quality of dispersion in the cases of both blends and composites. The rheological characteristics of multiphase polymeric materials provide valuable information on the morphologies of these materials, thereby rendering rheology an important tool for morphological assessment. Although rheology extensively affects the processabilities of polymeric materials in all processing operations, this review focuses on the roles of rheology in film blowing, electrospinning, centrifugal jet spinning, and the three-dimensional printing of polymeric materials, which are advanced processing operations that have gained significant research interest. This review offers a comprehensive overview of the fundamentals of morphology development and the aforementioned processing techniques; moreover, it covers all vital aspects related to the tailoring of the rheological characteristics of polymeric materials for achieving superior morphologies and high processabilities of these materials in advanced processing operations. Thus, this article provides a direction for future advancements in polymer processing. Furthermore, the superiority of elongational flow over shear flow in enhancing the quality of dispersion in multiphase polymeric materials and the role of extensional rheology in the advanced processing operations of these materials, which have rarely been discussed in previous reviews, have been critically analyzed in this review. In summary, this article offers new insights into the use of rheology in material and product development during advanced polymer-processing operations.

Determination and managerial implications of machine conditions for high-grade industrial polycaprolactam (nylon 6)

Polycaprolactam (PA6) is a thermoplastic polymeric material and because of its excellent mechanical properties, it has found an extensive application in military, textile, biomedical, building and construction, and several others. Because of its extensive applications, machine turning operation becomes a crucial section in the manufacturing of high-grade PA6. Hence, to have a high-grade PA6, turning operational conditions (cutting speed, feed rate and depth of cut) are optimized on the three surface profile responses and one material removal rate (MMR) with help probability based multi-response optimization analysis. This analysis is employed for an efficient multi-criterial decision making when PA6 is manufactured with a turning operation machine. The result revealed an optimal turning operational conditions to be 860 rpm cutting speed, 0.083 mm/rev feed rate, and 4 mm depth of cut. Furthermore, the analysis of variance and the numerical presentation of the turning operational conditions revealed that the feed rate is the most significant condition with a contribution of 34.09%, followed by cutting speed with a contribution of 32.05%, and then depth of cut with a contribution of 28.62%. Also, the confirmation analysis revealed a very high efficacy of the multi-objective optimization method employed in this study. This suggests that probability based multi-objective optimization is efficacious for optimizing machine conditions of any manufactured engineering material. It is interesting to state that the high confidence level placed on the considered turning operational conditions gives room for probable machine conditions adjustments for better PA6 in the case where different machine types are employed.

Synergistic effects of zinc borate and graphene on enhanced thermal stability and antimicrobial properties of poly(methyl methacrylate)

AbstractThe use of graphene nanoplatelets (GnP) as reinforcing material for thermoplastic polymer matrices, polymethyl methacrylate (PMMA) and zinc borate (ZnB), as an antimicrobial and fire‐retardant agent was studied. PMMA‐ZnB and PMMA‐GnP‐ZnB (ZG) composite films were fabricated with different ZnB concentrations (2.5, 5, 10 wt%) by solvent casting method using acetone. The effect of additives on the antimicrobial activity, thermal and mechanical properties, and surface morphologies of the composites were investigated. Antimicrobial surface activity tests were conducted against seven microorganisms, including bacterial and fungal species. An improvement in antimicrobial activity by up to 99.99% with increasing ZnB content was observed. Thermal stability was increased with increasing concentration of ZnB and a combination of ZnB and GnP additions. 10% ZG‐based composites increased the % char residue value of PMMA from 0.5% to 9.3%. The incorporation of the ZnB and GnP into the PMMA matrix resulted in an increase in the calculated limiting oxygen index (LOI). 10% and 50% weight loss temperature increased by 11.7°C and 3.7°C, respectively, for 10% ZG composites. The Young's modulus of the composites increased with increasing ZnB and a combination of ZnB and GnP loading (increasing by 16% to 2033 MPa with the addition of 10 wt% ZG). The commercial application for this study would be in high touch and piano black automotive interior, construction, and medical applications.

Reutilizing Single-Use Surgical Face Masks to Improve the Mechanical Properties of Concrete: A Feasibility Study

The coronavirus outbreak (COVID-19) has caused a sharp increase in the use of Single-Use Surgical Face Masks (SUSFMs) as personal protective equipment. These eventually end up in waste disposal facilities causing environmental pollution. Those that end up in the water bodies fragment into microplastics that affect marine life. Since the SUSFM materials are made from polypropylene, a thermoplastic polymer material that takes a long time to degrade, it is important to develop sustainable mitigation measures to remove them from the environment. This study investigated the feasibility of reutilizing SUSFMs in concrete. SUSFMs were shredded and added to C30/37 grade concrete in various percentages, 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, and 3.0%, by mass of cement content. The specimens were cured for 28 days before being tested for compressive strength, splitting tensile strength, and ultrasonic pulse velocity. The compressive strength decreased with an increase in the length and dosage content. The least decrease of 10.4% was observed at 0.5% content of 30mm length of SUSFM material. The results showed that concrete improved regarding splitting tensile strength, with the highest increase of 15.2% at 0.5% content of 30mm SUSFM. In addition, the overall quality of concrete remains at UPV values of more than 4000m/s registering good quality concrete. The results underscore the use SUSFM material in concrete in order to improve its quality while at the same time reducing waste.

An Edge-Filtered Optical Fiber Interrogator for Thermoplastic Polymer Analysis.

The present paper deals with the determination of thermodynamic quantities of thermoplastic polymers by using an optical fiber interrogator. Typically, laboratory methods such as differential scanning calorimetry (DSC) or thermomechanical analysis (TMA) are a reliable state-of-the-art option for thermal polymer analysis. The related laboratory commodities for such methods are of high cost and are impractical for field applications. In this work, an edge-filter-based optical fiber interrogator, which was originally developed to detect the reflection spectrum of fiber Bragg grating sensors, is utilized for the detection of the boundary reflection intensities of the cleaved end of a standard telecommunication optical fiber (SMF28e). By means of the Fresnel equations, the temperature-dependent refractive index of thermoplastic polymer materials is measured. Demonstrated with the amorphous thermoplastic polymers polyetherimide (PEI) and polyethersulfone (PES), an alternative to DSC and TMA is presented as the glass transition temperatures and coefficients of thermal expansion are derived. A DSC alternative in the semi-crystalline polymer analysis with the absence of a crystal structure is shown as the melting temperature and cooling-rate-dependent crystallization temperatures of polyether ether ketone (PEEK) are detected. The proposed method shows that thermal thermoplastic analysis can be performed with a flexible, low-cost and multipurpose device.

Fabrication of highly carboxylated thermoplastic nanofibrous membranes for efficient absorption and separation of protein

Developing high-performance chromatographic media is of great significance for efficient protein adsorption and separation. Herein, the thermoplastic-poly(vinyl alcohol-co-ethylene) (EVOH) nanofibrous membranes (NFMs) were fabricated through structure controlled high-speed flow deposition process from EVOH nanofibrous suspensions. Butane tetracarboxylic acid (BTCA) was grafted onto EVOH NFMs to form chromatographic media by impregnation method. The obtained EVOH/BTCA NFMs with highly tortuous structure, excellent structural stability, good hydrophilicity and abundant active carboxyl groups possess selective absorption to positively charge proteins via electrostatic interaction. With increasing BTCA contents, the absorption capacity (take lysozyme as template protein) increased gradually and achieved a maximum absorption capacity of 749.3 mg/g. Meanwhile, the protein absorption performance of EVOH/BTCA NFMs is optimized by the properties of protein solution, physical properties of substrate EVOH NFMs and grafting temperature. EVOH/BTCA NFMs exhibit good reusability and maintain a relatively stable absorption capacity after 10 absorption-elution cycles. Furthermore, superior acid and alkaline resistance of EVOH/BTCA NFMs was proved through being treated in acid and alkaline solutions for 24 h. EVOH/BTCA NFMs can effectively extract lysozyme from egg white. A successful scale-up of such low-cost and high-performance membranes could provide some insights for the design and development of thermoplastic polymeric nanofibrous-based materials with protein separation and purification.

DEVELOPMENT OF IMPROVED ROBOTICS EXTRUDER LOADING SYSTEM

The relevance of the study is due to the fact that the loading of granulated polymer material into the working hopper of extruders is mainly carried out manually from bags by production operators. The capacity of working hoppers of extruders is limited due to the fact that with a significant height of the bulk material, an increase in static pressure occurs in the lower layers, which leads to the formation of vaults, uneven supply of polymer into the material cylinder and deterioration of the quality of products. Since the work process of extrusion is continuous and lasts an entire work shift, there is a need to constantly control the filling level of the work hoppers of the extruders. The paper proposes a robotic extruder loading system for the processing of thermoplastic polymer materials into long products (pipes, profiles, films, etc.). The paper proposes a system for loading one or more extruders, which contains a large hopper loaded with raw materials for an entire work shift. From this hopper, the working hopper of the extruder is automatically filled with the help of a screw feeder. Automatic monitoring of the filling status of the hoppers is carried out by a microcontroller with the help of raw material level sensors. The object of research is the process of automatic control of periodic loading of loose materials into technological machines. The subject of the research is a robotic system for loading granulated polymers into the working hoppers of extruders. The purpose of the research is to develop a control system for devices for periodic dosing of granular polymer materials and loading them into working hoppers of limited capacity, which can be used in extruders. The task of the work is an analytical study of the effectiveness of the application of extruder loading systems based on a screw feeder and the development of its design and automatic control scheme. The methodological and theoretical basis of the research are the basic provisions of the theory of automatic control of technological processes, the design of transport equipment for loose media, and the basis of the calculation of machine parts. A scientific novelty is that the work proposed for the first time a device for automatic control of the extruder loading system based on a microcontroller with the possibility of programming the work algorithm. The results of the work can be used to create new systems for controlling the operation of equipment for processing polymer materials and creating new designs. The methodological and theoretical basis of the research are the basic provisions of the theory of automatic control of technological processes, the design of transport equipment for loose media, and the basis of the calculation of machine parts. A scientific novelty is that the work proposed for the first time a device for automatic control of the extruder loading system based on a microcontroller with the possibility of programming the work algorithm. The results of the work can be used to create new systems for controlling the operation of equipment for processing polymer materials and creating new designs.

Study on Adhesion Properties and Process Parameters of Electroless Deposited Ni-P Alloy for PEEK and Its Modified Materials

Polyetheretherketone (PEEK) and its fiber-reinforced materials are thermoplastic polymer materials with broad application prospects. Depositing Ni-P alloy on them can improve their poor conductivity and electromagnetic shielding performance, and further expand their application field. The application effect of the plated parts is significantly impacted by the bonding strength between PEEK and coating. The bonding strength between non-metallic substrate and coating is largely influenced by the surface characteristics of the substrate. Therefore, it is significant to study how the surface roughness of PEEK materials and the modified fibers in materials affect the adhesion of the coating. In this study, Ni-P alloy was electroless deposited on PEEK, 30% carbon-fiber-reinforced PEEK (CF30/PEEK), and 30% glass-fiber-reinforced PEEK (GF30/PEEK) with varying surface roughness. The influence of surface roughness and modified fibers on the coating adhesion was studied. Additionally, the effect of the concentrations of nickel sulfate, sodium hypophosphite, pH, and temperature on the deposition rate of the coating was investigated for the three materials. Based on the highest deposition rate, the process parameters were then optimized. The results demonstrated that as surface roughness increased, adhesion between substrate and coating first increased and then decreased. The surface roughness Ra of 0.4 μm produced the highest coating adhesion. Additionally, fiber-reinforced PEEK adhered to coatings more effectively than PEEK did. The mechanism of the difference in bonding strength between different PEEK-modified materials and coatings was revealed. The optimal process parameters were: nickel sulfate: 25 g/L, sodium hypophosphite: 30 g/L, pH: 5.0, and temperature: 70 °C.

Quality Aspects in the Compounding of Plastic Recyclate

Compounding is the final processing step for quality adjustment and control before recycled thermoplastic polymer material can be introduced into production processes. Motivated by the need for higher recyclate shares, the research question is which quality problems recycling compounders are encountered in practice, where they occur, and which mitigation options might be reasonable. Therefore, an online survey with 20 recycling compounders based in Germany was conducted asking about typical processing steps and processed materials, test procedures for quality assurance, quality problems, and possibilities for reducing quality problems. Results show that compounders mainly name impurities and contaminations of the input material as challenging and the reason for quality problems. The study shows that the problems are not dependent on the material input type. Quality problems occur along the entire secondary value chain, with companies manufacturing components themselves being particularly affected. The composition determination of the input materials helps to minimize quality problems.

Spring‐Like Ammonium Salt Assisting Stress Release for Low‐Temperature Deposited FAPbI3 Films Toward Flexible Photovoltaic Application

AbstractThe substrates of conventional flexible perovskite solar cells (FPSCs) are thermoplastic polymer material polyethylene naphthalate (PEN), which will deform during high temperature annealing process. In addition, lead iodide (PbI2) permanently formed and the substrate undergoes reversible deformation from 20 °C to 200 °C and back to 20 °C. Therefore, to balance the substrate supporting capacity and the crystalline quality of narrow band gap α‐phase formamidinium lead iodide (α‐FAPbI3), an annealing process of 120 °C for 30 minutes is determined. Additionally, there will also be a large number of gaps and lattice strain at the perovskite grain boundaries during the annealing process as the FAPbI3 phase transition is accompanied by much lattice shrinkage. As a result, 1,6‐hexanediammonium diiodide (HADI) is chosen to passivate the defects and release the stress of perovskite film. Therefore, a recorded 1.4% extended stretch rate of the flexible film is attained. Finally, the champion PCE of 21.14% under AM 1.5G and 31.52% under 1062 lux is achieved after HADI treatment, accompanied by a better long‐term and mechanical stability. This study provides annealing process optimization and stress relief strategies for the further development of narrow band gap FPSCs.