Thermoplastic Materials Research Articles

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.

Design and synthesis of Ag NPs/Cellulose nanofiber-starch nano-bio composites for packaging applications

Addressing problems due to conventional plastics requires a comprehensive approach involving waste reduction, improved waste management practices, and the development of sustainable alternatives to conventional plastics. In this study, a system was designed that can decorate cellulose nanofiber with silver nanoparticles (AgNP) and then used as a reinforcing agent in thermoplastic starch matrix. The composites were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM) and transport properties. The morphology and chemical modification of cellulose nanomaterials with silver nanoparticles were confirmed by FESEM, TEM and FTIR and the results indicated proper adhesion of silver nanoparticles in cellulose nanofiber. The addition of AgNP decorated cellulose nanofiber on thermoplastic starch matrix could effectively reduce cracks and pores and improves the overall performance of nanocomposite films. The unique properties of starch nanoparticles make them a promising candidate for diverse applications, showcasing their potential as a sustainable and versatile nanomaterial.

Material Characterizations of the Polymers Reinforced with Recycled Flexible Plastic Blends as Filament for 3D Printing

The high consumption of single-use plastics and the low recycling rates have seriously polluted the soil and ocean environments. Thermoplastic materials from recycling can be used to make filaments for 3D printing. This study is focused on preparing, characterizing, and comparing the polymers reinforced with recycled flexible plastic blends to be used as a filament in additive manufacturing. In this regard, two types of polymers were used to create the filament: High-Density Polyethylene (HDPE) and Polypropylene (PP), which were mixed with recycled flexible plastic (RF). The mixture was initially used to create filament by using a single extrusion machine, with various ratios of virgin HDPE and PP to recycled flexible plastic (in weight%) at temperatures of 190°C and 230°C. Then, the filament blends were characterized using infrared (IR) spectroscopy, thermogravimetric analysis (TGA), and field emission scanning electron microscopy (FESEM). TGA analyses revealed that RF can increase the thermal stability of V- HDPE and V-PP upon blending, and HDPE/RF blends show a higher decomposition temperature than PP/RF. FESEM indicated that adding 30% RF is the best percentage for both polymer blends where the structure appears ductile. It can be concluded that the HDPE 70% blend is suitable for 3D printer filament as it showed the best decomposition temperature and the ductility of the fracture structure, which meet the requirements for 3D printer filament.

Experimental analysis of the effects of different production directions on the mechanical characteristics of ABS, PLA, and PETG materials produced by FDM

Abstract One of the most researched technologies among technologies used for producing complex and diverse parts today is additive manufacturing. In additive manufacturing, production can be carried out using thermoplastic and metal materials without requiring an additional process. Among the additive manufacturing technologies, the Fused Filament Fabrication (FFF) method is the most widely used method worldwide due to its affordability and broad application area. FFF is a method in which part formation is achieved by depositing melted materials on each other. In recent years, polymer materials such as polylactic acid (PLA), polyethylene terephthalate glycol (PETG), and acrylonitrile butadiene styrene (ABS) have been frequently used in many industrial areas in the FFF method because they are lightweight, inexpensive, sustainable, and provide sufficient strength for engineering applications. This study conducted tensile, three-point bending, Charpy, and compression tests on PLA, PETG, and ABS materials at angles of 15°–75° and 30°–60°, and the results were compared.

Influence of Giant Reed (Arundo Donax L.) Culms Processing Procedure on Physicochemical, Rheological, and Thermomechanical Properties of Polyethylene Composites

ABSTRACT Giant reed (Arundo donax L.) is a plant species with a high growth rate and low requirements, which makes it particularly interesting for the production of different bioproducts, including natural fibers. This work assesses the use of fibers obtained from reed culms as reinforcement for a high-density polyethylene (HDPE) matrix. Two different lignocellulosic materials were used: i) shredded culms and ii) fibers obtained by culms processing, which have not been reported yet in literature as fillers for thermoplastic materials. A good stress transfer for the fibrous composites was observed, with significant increases in mechanical properties; composites with 20% fiber provided a tensile elastic modulus of almost 1900 MPa (78% increase versus neat HDPE) and a flexural one of 1500 MPa (100% increase), with an improvement of 15% in impact strength. On the other hand, composites with 20% shredded biomass increased by 50% the tensile elastic modulus (reaching 1560 MPa) and the flexural one (up to 1500 MPa), without significant changes in impact strength. The type of filler is more than its ratio; composites containing fibers resulted in a higher performance than the ones with shredded materials due to the higher aspect ratio of fibers.

Bio-functional hydroxyapatite-coated 3D porous polyetherketoneketone scaffold for enhanced osteogenesis and osteointegration in orthopedic applications.

Polyetherketoneketone (PEKK), a high-performance thermoplastic special engineering material, maintains bone-like mechanical properties and has received considerable attention in the biomedical field. The 3D printing technique enables the production of porous scaffolds with a honeycomb structure featuring precisely controlled pore size, porosity and interconnectivity, which holds significant potential for applications in tissue engineering. The ideal pore architecture of porous PEKK scaffolds has yet to be elucidated. Porous PEKK scaffolds with five pore sizes P200 (225 ± 9.8 μm), P400 (411 ± 22.1 μm), P600 (596 ± 23.4 μm), P800 (786 ± 24.2 μm) and P1000 (993 ± 26.0 μm) were produced by a 3D printer. Subsequently, the optimum pore size, the P600, for mechanical properties and osteogenesis was selected based on in vitro experiments. To improve the interfacial bioactivity of porous PEKK scaffolds, hydroxyapatite (HAp) crystals were generated via in situ biomimetic mineralization induced by the phase-transited lysozyme coating. Herein, a micro/nanostructured surface showing HAp crystals on PEKK scaffold was developed. In vitro and in vivo experiments confirmed that the porous PEKK-HAp scaffolds exhibited highly interconnected pores and functional surface structures that were favorable for biocompatibility and osteoinductivity, which boosted bone regeneration. Therefore, this work not only demonstrates that the pore structure of the P600 scaffold is suitable for PEKK orthopedic implants but also sheds light on a synergistic approach involving 3D printing and biomimetic mineralization, which has the potential to yield customized 3D PEKK-HAp scaffolds with enhanced osteoinductivity and osteogenesis, offering a promising strategy for bone tissue engineering.

CHARACTERISTICS OF THERMOPLASTIC POLYMER DENTURE BASE MATERIALS FOR PROSTHODONTIC CONSTRUCTIONS

Introduction. In dentistry, there is a wide range of thermoplastic polymers for the removable constructions of dental prostheses, which are extremely promising in modern dental practice. Successful prosthetics of patients will depend on the properties of the selected structural materials.. Purpose of the study was to summarize current information, based on a review of literary sources, on the use of thermoplastic base materials for the manufacture of removable prostheses and improves the effectiveness of orthopedic treatment of patients with complete or partial absence of teeth. Methods. A literature review was conducted using PubMed, Web of Science, SCOPUS, Google Scholar up to January 2024. There was no restriction on the date of publication or language. Searches using the MeSH (Medical Subject Headings) terms were conducted using synonyms and combinations of the following search terms: "removable prosthetics", "dental base materials", "thermoplastics" "materials science", and "adaptation". Used methods: bibliographic and analytical. Results. Thermoplastic materials are characterized by bioinertness for the organism, because they do not contain residual monomer. The technology of injection molding of thermoplastic polymers is considered as a promising technology in modern dentistry to achieve high aesthetic standards. The general characteristic of this group of materials is the absence of residual monomer and, accordingly, their biological indifference, a high level of plasticity, precision during the manufacture of the prosthesis, and a wide range of colours. Conclusion. Polymer denture base plastics do not have optimal physico-mechanical, biological and surface characteristics, so the search for new materials for the manufacture of removable prostheses remains a promising direction

RELIABILITY ASSESSMENT OF ELECTROMECHANICAL MODULE WITH ASSOCIATION AMONG RELIABILITY INDICATORS

This paper presents the reliability assessment results for electromechanical modules, including carbon fiber reinforced composite with thermoplastic matrix, aluminium alloy, and steel housing, through the analysis of competing risks, establishing an association among reliability indicators and non-stationary failure flow using the Weibull probability density function. It has been demonstrated that the estimated probabilities of reliability operations and failure are merely approximations and may deviate from the actual values. This analysis correlates with the estimation of mutual competing risks in the operation of planetary gearbox housing constructed from composite materials. It has been confirmed that the estimated probability of failures is asymptotically effective. A comparative analysis illustrates reliance on simulation methods for planetary gearbox housing made of carbon fiber reinforced composite with a thermoplastic matrix, aluminium alloy, and steel, focusing on parameters such as von Mises stress and deformation (deflection). It has been proven that the electromechanical module, including carbon fiber reinforced composite with thermoplastic matrix, aluminium alloy, and steel planetary gearbox housing is the most reliable, with the lowest heat transfer coefficient, but with the lowest strength.

Accuracy of arch expansion with two thermoplastic materials in Invisalign® patients: EX30® and SmartTrack®.

The purpose of this retrospective study was to compare accuracy of arch expansion using two different thermoplastic materials in Invisalign aligners: EX30® (Polyethylene Terephthalate Glycol, or PETG) and SmartTrack® (polyurethane). The study sample comprised 65 adult patients consecutively treated with Invisalign from two private practices: group 1 - treated with EX30® (358 teeth) and group 2 - treated with SmartTrack® (888 teeth). Six hundred and twenty-three measurements were assessed in three digital models throughout treatment: model 1 - initial, model 2 - predicted tooth position, and model 3 - achieved position. Sixteen reference points per arch were marked and, after best alignment, 2 points per tooth were copied from one digital model to another. Linear values of both arches were measured for canines, premolars, and first molars: on lingual gingival margins and cusp tips of every tooth. Comparisons were performed by Wilcoxon and Mann-Whitney test. Both termoplastic materials presented significant differences between predicted and achieved values for all measurements, except for the lower molar cusp tip in the SmartTrack® group. There is no statistical difference in the accuracy of transverse expansion between these two materials. Overall accuracy for EX30® aligners in maxilla and mandible were found to be 37 and 38%, respectively; and Smarttrack® presented an overall accuracy of 56.62% in the maxilla and 68.72% in the mandible. It is not possible to affirm one material expands better than the other. Further controlled clinical studies should be conducted comparing SmartTrack® and EX30® under similar conditions.

Computer-based design and development of a fully automated assembly of aircraft doors made of thermoplastic composite material

For production of aircraft doors using innovative lightweight materials, a fully automated assembly process was developed. Therefor a door structure of an overwing-exit-door is to be joined from thermoplastic composite material components. The innovative material enable the use of new joining concepts. The assembly process was virtually simulated in order to forecast production time, process sequence, provision of operating resources and investment costs. Relevant manufacturing equipment was designed and accessibilities of the clamping and joining tools as well as collision areas were determined and optimized. To quality management, process control concept was developed with which geometric deviations of the components can be automatically compensated.

Composite heat-resistant materials based on thermoplastic matrices

Composite heat-resistant materials based on thermoplastic matrices

Impact of Element Layout and Notching Technique on the Fracture Toughness of FFF-Processed Thermoplastics

This work explores the effects of notching method and element layout on the fracture loading properties of thermoplastic materials processed using fused filament fabrication (FFF). Three common thermoplastic materials were used (acrylonitrile butadiene styrene, polylatide, and polycarbonate). Four different notching methods were used, with printed and machined notches and with and without pre-cracking on ASTM D5045 compact tension specimens (n = 36). It was concluded that the notching method has a statistically significant impact on the sample preparation and that pre-cracking is necessary in all cases. Using this information to prepare specimens, a designed experiment using four different element layout strategies and two different nozzle sizes was completed with a total of 72 tests. The layout pattern was shown to have a very strong effect on the maximum fracture load, with the nozzle size showing a smaller but still statistically significant impact. With the exception of one layout using polycarbonate with likely design-driven printing defects, the results were very consistent through several replications. The results of this study are useful for making design decisions with FFF-processed materials, for better understanding the impact of the process design, and for working toward standardized printing and testing methods for additive manufacturing.

Features of obtaining wood-polymer composite materials

Composite materials are a trend and an inspiring area of applied research today. Plant-based materials are versatile ones. Their properties can be modified with additives and processing technology to produce a very large range of products in various applications, for decking, street and garden furniture, siding, picket fences, containers and pallets and much more. The properties of wood composite materials vary greatly depending on the recipe, method and technological parameters of processing. The paper presents a solution to use the best properties of wood and thermoplastic materials. Production of an analogue of plastic based on wood raw materials is proposed. The object of study in this work were samples of composites based on polyvinyl chloride and wood flour, containing calcium-zinc stabilizers and lubricants of various brands. The research studies the influence of various brands of complex stabilizers and lubricants on the thermal stability and water absorption of composite materials based on plant raw materials.

Integrated CAD/CAM Approach for Experimental Stands in Hydrogen Explosion Analysis

Hydrogen is considered a promising clean energy carrier gas for the future and is used in fuel cell systems to generate electricity without producing greenhouse gas emissions. However, the safe storage and handling of hydrogen are essential for the widespread adoption of hydrogen as an alternative energy source. Research into hydrogen explosions is aimed at developing safe storage methods, safety guidelines, and accident prevention measures - crucial objectives for the sustainable growth of the hydrogen economy. Fundamental research into fast hydrogen combustion requires specially designed and built experimental stands to ensure both safe operation and recording of explosion parameters. More than a simple combustion chamber, often the geometry of the stands must contain elements to increase the complexity of the explosion process. In this respect, this paper deals with the possibilities of designing and 3D printing obstacles that can be placed in the path of hydrogen explosions on research stands to modify the cross-section, direct the pressure waves, turbulence the fluid movements, or even suppress the flame front. By combining the computer-aided modeling and design facilities offered by the Autodesk Fusion 360 software, digitized models are converted into 3D objects by the process of dividing them into thin horizontal layers (slices) and transmitting the information thus generated to the 3D printer, using Ultimaker Cura. Here, through the process of material deposition and fusion (FDM), the thermoplastic material is extruded, deposited layer by layer, rapidly cooling, and solidifying to form the final object.

Sustainable Furniture Joints: Leveraging Fused Deposition Modeling (FDM) for Eco-Friendly Design

Integrating form, function, and material selection has been fundamental in furniture design and production. Traditional methods, particularly in joint creation, demand skilled craftsmanship and time-intensive processes. However, the emergence of 3D printing technology, specifically fused deposition modeling (FDM), has revolutionized furniture joint production. This study investigates the sustainable application of FDM for creating furniture joints, emphasizing eco- friendly design and efficient material utilization. To optimize the joinery system using 3D printing, researchers have conducted structured interviews with experts in the Malaysian 3D printing field. Their insights guided the development of guidelines for selecting appropriate materials and optimizing joint geometries. In furniture manufacturing, FDM enables precise joint components through layer-by- layer construction using thermoplastic materials. Unlike traditional methods that often result in wood waste, FDM minimizes material consumption. Designer- generated joint designs produced seamlessly via 3D printing reduce production time and enhance precision. Cost-effectiveness further positions FDM as a sustainable alternative for furniture production. This research focuses on two commonly used FDM materials: Acrylonitrile Butadiene Styrene (ABS) and Polylactic Acid (PLA). By providing guidelines for selecting appropriate materials, it will eventually empower designers and manufacturers to create furniture joints that align with sustainability goals. The resulting joints exhibit superior accuracy compared to manual craftsmanship, contributing to both environmental conservation and innovation within the Malaysian furniture industry

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

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

Shake, shear, and grind! - the evolution of mechanoredox polymerization methodology.

In the last half decade, mechanoredox catalysis has enabled an entirely new genre of polymerization methodology. In this paradigm, mechanical force, such as ultrasonic cavitation bubble collapse or ball mill grinding, polarizes piezoelectric nanoparticles; the resultant piezopotential drives the redox processes necessary for free- and controlled-radical polymerizations. Since being introduced, evolution of these methods facilitates exploration of mechanistic underpinnings behind key electron-transfer events. Mechanical force has not only been identified as a "greener" alternative to more traditional reaction stimuli (e.g., heat, light) for the synthesis of commodity polymers, but also a potential technology to enable the production of novel thermoplastic and thermoset materials that are either challenging, or even impossible, to access using conventional solution-state approaches. In this Feature Article, significant contributions to such methods are highlighted within. Advances and ongoing challenges in both ultrasound and ball milling driven reactions for radical polymerization and crosslinking are identified and discussed.

Advanced manufacturing technologies in thermoplastic composite material aimed at the aeronautical sector

Advanced manufacturing technologies in thermoplastic composite material aimed at the aeronautical sector

Impact behavior of thermoplastic matrix composites reinforced with basalt fibers and manufactured by RTM

Impact behavior of thermoplastic matrix composites reinforced with basalt fibers and manufactured by RTM

Comparative analysis of ABS materials mechanical properties

Additive Manufacturing (AM) has shown rapid development during the last decades. More commonly known as 3D printing, this technology offers significant benefits for the fabrication of physical models with complex geometries. This technology started as a valuable tool for prototyping purposes but is considered for general manufacturing due to the production cycle shortening and less (if none) material waste. Out of seven possible AM technologies, this research covers three of them, namely: Fused Deposition Modeling (FDM), Stereolithography (SLA), and Digital Light Processing (DLP). Although, ABS thermoplastic material is a thoroughly researched AM material, a new resin material also called ABS is an interesting object for research. Hence, the aim of this paper is to acquire the tensile properties of this material and to compare them to the “original” ABS thermoplastic material.