Papers by Keyword: Polyethylene Terephthalate

Abstract: The successful implementation of fused filament fabrication (FFF) 3D printing using recycled plastics requires a deep understanding of the thermal behavior of the plastics throughout the printing process. This study investigated the influence of wall thickness of the printed sample, nozzle temperature, and cooling fan speed during 3D printing on the cooling rate, crystallinity, and tensile properties of recycled polyethylene terephthalate (rPET). The experimental process commenced with the collection of discarded rPET bottles, followed by thorough cleaning and washing to remove any adhesives and contaminants. Afterward, the bottles were cut and ground into flakes and then converted into filaments using a single-screw filament extrusion process. In-situ thermal analysis was conducted by integrating an infrared (IR) thermal camera into the 3D printing setup to monitor real-time temperature changes during the printing process. Results revealed that cooling rates increased markedly with reduced wall thickness, rising from 17.53 °C/min for the 3.6 mm wall thickness to 62.92 °C/min for the 1.2 mm wall thickness. Nozzle temperature exhibited a non-linear influence, with the highest cooling rate of 65.47 °C/min recorded at 240 °C, while enhanced cooling fan speed (100%) further accelerated cooling to 45.00 °C/min. Differential scanning calorimetry (DSC) and Raman spectroscopy confirmed that a slower cooling rate generally promoted crystallinity, which was observed in thick-walled and low-cooling speed prints. Tensile testing demonstrated a strong correlation between crystallinity and tensile performance, with ultimate tensile strength (UTS) reaching 55 MPa at 240 °C and 54.8 MPa at 25% cooling fan speed, outperforming previously reported rPET values. The use of rPET in FFF and the findings of this study contribute to the further exploration of rPET's potential in sustainable additive manufacturing practices.

Abstract: Deep eutectic solvents (DES) are widely used in many fields due to their properties such as low cost, easy synthesis, low toxicity, and biodegradability. The following study selected tropine and hydrated metal salts to synthesize a series of new deep eutectic solvents as catalysts for exploring the alcoholysis reaction of PET. Then the effects of the types of DES, catalyst composition, reaction time and temperature on the alcoholysis results of PET were investigated. Using a low melting solvent of tropine/zinc acetate with a molar ratio of 4:1 as a catalyst, a reaction time of 2 h, and temperature of 180°C, the conversion rate of PET was nearly 80%, and the yield of BHET was also 80%, which was further employed to prepare nano carbon dots through simple way.

Abstract: Motivated by the environmental issues generated by the accumulation of waste from discarded plastic bottles and recognizing the utility of plastic properties in engineering, this research aimed to evaluate the application of plastic bottle fibers in the geotechnical improvement of tropical soils. In this context, the influence of quantity, roughness, and width of plastic bottle fibers on the shear strength parameters of soil- fiber mixtures, of two tropical residual soils, was analyzed. The fibers used in this study are made of Polyethylene Terephthalate (PET), generated from soft drink bottles, and added to the soil in different widths, textures, and contents. Results of the direct shear test showed higher shear strength for all soil-fiber systems compared to fiber-free mixtures. Additionally, the findings indicated that the systems with rough fibers presented better performances for clayey soil, whereas those with smooth fibers obtained better behavior for sandy soil. The cohesion results highlighted the better performance of mixtures with 0.5% fibers when compared to mixtures with 1% fibers. The enhancement of mechanical properties obtained in the studied soil-fiber systems demonstrates the potential application of these composites in geotechnical works.

Abstract: This study proposed using Polyethylene Terephthalate (PET) and Faunus ater shell ash (FAA) waste as asphalt binder additives and filler substitutions, respectively, to increase the strength and stability of porous asphalt. A thorough investigation of porous asphalt mixture properties was carried out using a permeability test, void in the mix (VIM), Marshall stability, and cantabro loss (CL). In this study, the stone dust filler was substituted by 0%, 50%, and 100% of FAA. In addition, 2%, 4%, and 6% of PET were used as asphalt binder additives. The permeability test result was in line with the VIM measurement, resulting in Mix 2 (50% stone dust, 50%FAA, and 2% PET) having the highest permeability and VIM value. In comparison, Mix 4 (100% stone dust and 4% PET) has the lowest permeability and VIM value. The Marshal stability results were in reverse with the permeability and VIM value, where Mix 4 resulted in the highest Marshall stability of 1519 kg. The majority of the CL test result was in line with the permeability and VIM value, where the only mixture that failed to satisfy the minimum 35% of CL value was Mix 2 with the CL value of 36%.

Abstract: The paper discusses the change of phosphogypsum surface state produced by Apatit (Cherepovetsky branch, Vologda region) during calcination at 298-1173 K. The authors have determined the average size of its crystallites and studied the atomic composition of raw materials and finished composites that include crushed rock fraction (5-10 mm), oil bitumen, and polyethylene terephthalate additive (1.0-1.2 wt. %). The compounds present in calcined phosphogypsum have been analyzed by X-ray diffraction. The granulate was obtained by pelletizing phosphogypsum with a mixture of the above components. The paper presents the assessment of its physical and chemical properties. The granulated composites based on the specified samples of calcined phosphogypsum, bitumen, and melted polyethylene terephthalate waste show great promise for construction road works in European countries in summer and winter, as well as countries with tropical climates.

Abstract: The use of recycled materials to replace natural and artificial materials represents an interesting and real possibility for all industrial sectors to contribute to the reduction of the amount of waste disposed of and non-renewable resources consumed. This study reports the results of the measurements of the sound absorption coefficient carried out on specimens obtained from the recycling of different materials. A sustainable development of our planet requires us to adopt materials recycling policies to ensure the economical use of resources. Two types of materials have been studied: material obtained from the recycling of plastic bottles, and a material obtained from the recycling of asphalt milled. Both materials showed interesting sound absorption performances covering different frequency ranges.

Abstract: The aim of this paper is to review the literature on Materials science to identify the current research and to provide direction for future research in thermal properties of the concrete block composite, either with Polyethylene Terephthalate (PET) or Polystyrene (PS), presenting the opportunity to make an important methodological contribution by applying systematic review in three areas of Materials science: Composites, Building Materials, as well as Testing and Evaluation of Materials. This is a growing interdisciplinary field since there are no current comparative papers addressing both PET and PS in the same research for concrete composites. Papers investigating to what extent, what type and how academic publications are integrated on the analysis of the characteristics of the two recycled polymers (PET and PS), to improve the thermal properties of the concrete block and contribute to the research of sustainable thermal comfort in homes. They were reviewed, keywords were identified within a framework of composites, building materials, as well as testing and evaluation of materials, and a lexical analysis of the papers was conducted. The results of current research show that both forms of recycling (PS and PET), combined with concrete, have sustainability in thermal comfort. The analysis reveals that previous research has focused on PET-Concrete (i.e., concrete-PET polymer composite) since it is more viable, due to its large amount of recycling. While this has benefited home builders in their ability to respond with some thermal comfort with higher construction efficiency, it also clarifies that there has been research done on PS-Concrete (i.e., concrete-PS polymer composite), presenting greater thermal comfort, because it has lower thermal conductivity. This finding suggests the need for further research within this narrow field, with absence of data, since most prescriptive recommendations have not been tested and lack practical applications, which is why the need for more empirical and experimental studies are identified. Based on the novelty of the PET or PS recycling concepts, we highlight the need of better collaboration between academic disciplines, such as engineering and architecture to provide better experimental evidence for recycling of polymers, including empirical approaches for the different types of composites and aggregate distributions, which can be made with concrete to improve thermal insulation performance and energy savings for manufacturers.

Abstract: 3D printing is a promising digital manufacturing technique that manufactures product parts in a layer fashion. Fused deposition modeling (FDM) is a widely used 3D printing technique that produces components by heating, extruding, and depositing the filaments of thermoplastic polymers. Meanwhile, the properties of FDM-produced parts are significantly influenced by process parameters. These process parameters have different advantages that need to be investigated. This paper examines the effect of some process parameters on the tensile properties of some components produced using FDM technique. The study is performed on polylactic acid (PLA) material, using full factorial experimental design. Furthermore, three process parameter—material, infill density, and infill pattern—are considered. The results indicate that only the infill pattern significantly influences the tensile properties of the model.

Abstract: The FTIR spectroscopy method was used to investigate the changes in palm, sunflower and rapeseed oil at thermal influence up to 195°C, and also in contact with polyethylene terephthalate (PET) and polyamide (PA-6) film for 1 hour 50 minutes. It has been found that heating the oil to 195°C in contact with PET and PA-6 film does not lead to any noticeable changes in the IK oil absorption spectra. Peaks characteristic of polymers (in areas of 1535 and 1634 cm^-1), are not observed.

Abstract: Semitransparent bulk-heterojunction (BHJ) solar cells have attracted a strong attention due to the possible use in new photovoltaic applications. However, semitransparent BHJ solar cells on flexible substrates have not yet been developed. In this work, flexible BHJ solar cells were fabricated on an ITO/PET substrate using an inverted PET/ITO/PFN/PTB7:PC₇₁BM/MoO₃/Au device structure. The power conversion efficiency (PCE) of the device was 3.4 %. Fabrication of semitransparent solar cells was further demonstrated utilizing a MoO₃/Au/MoO₃ transparent anode. The semitransparent solar cell showed bifacial energy generation when illuminated from both front and backside. The PCEs with illumination from the ITO or Au/MoO₃ side were 2.7 % and 2.1 %, respectively. These results showed that a semitransparent PTB7:PC₇₁BM solar cell was successfully fabricated on flexible PET substrates.