Polyethylene Terephthalate Fabrics Research Articles

Efficient glycolysis of waste polyethylene terephthalate textiles over Zn-MCM-41 catalysts

Polyethylene terephthalate (PET), also known as polyester, is extensively utilized in the textile industry. The most commonly used chemical degradation method of PET is ethylene glycol (EG) glycolysis, which enables a closed-loop recovery process suitable for large-scale production. In this study, a new type of heterogeneous catalyst (Zn-MCM-41) was proposed for glycolysis of waste PET textiles, and their catalytic performance is much higher than other mesoporous zeolites. Under optimal reaction conditions, over Zn-MCM-41–25 (Si/Al molar ratio of 25) catalyst PET achieved a conversion ratio of 100 %, with bis-hydroxyethyl terephthalate (BHET) yield reaching 81.4 %. XPS results show that zinc is mainly presented as the state of Zn2+, resulting in excellent stability of the catalyst. HPLC and LCMS analyses were conducted on the products obtained from PET glycolysis, revealing that only a small amount of oligomers were generated during the process. These oligomers primarily consisted of dimer [BHET]2 and trimer [BHET]3. The Zn-MCM-41–25 catalyst also demonstrates exceptional performance in colored waste PET textiles glycolysis. Furthermore, we investigated the kinetics of PET glycolysis and determined it to follow first-order kinetics with an activation energy value of 210.03 kJ mol−1. Additionally, HPLC methods was established for analyzing glycolysis products and recovering catalysts using a simple filtration technique. The results demonstrate that even after five cycles, the catalyst maintains its high catalytic activity.

Ultrasonic-assisted alkali hydrolysis of polyethylene terephthalate fabric and its effect on the microstructure and dyeing properties of fibers

Abstract In this study, ultrasound energy was applied to assist the alkali hydrolysis of polyethylene terephthalate (PET) fabric, and then, the results were compared with those of the mechanical oscillating method, which was used as the control. The effects of various factors such as the sodium hydroxide concentration, the dosage of dodecyl dimethyl benzyl ammonium chloride (DDBAC), and the frequency on the weight loss of the PET fabrics were systematically investigated. The surface appearance and microstructures of the treated fibers with different methods were analyzed using a scanning electron microscope and X-ray diffraction, respectively. The results showed that DDBAC played a prominent accelerating role in the hydrolysis of the PET polymer, and the frequency had a great influence on the weight loss of the PET fabric. Ultrasound with a frequency of 60 kHz showed a similar decomposition rate as the control, resulting in similar weight loss, which was the highest value among the three frequencies (20, 60, and 80 kHz). In addition, the application of ultrasonic energy led to more pits on the fiber surface, a smaller average grain size, and decreased crystallinity of the treated fibers, while the mechanical oscillating method resulted in slightly increased crystallinity. By comparing the K/S value of the dyed fabrics with two commercial disperse dyes, we found that the treatment method had no obvious correlation with the color depth of the treated fabric.

Global Polyethylene Terephthalate (PET) Plastic Supply Chain Resource Metabolism Efficiency and Carbon Emissions Co-Reduction Strategies

Polyethylene terephthalate (PET) is widely used as a primary plastic packaging material in the global socio-economic system. However, research on the metabolic characteristics of the PET industry across different countries, particularly regarding the entire life cycle supply chain of PET, remains insufficient, significantly hindering progress in addressing plastic pollution worldwide. This study employs the Life Cycle Assessment-Material Flow Analysis (LCA-MFA) method to comprehensively analyze the environmental impacts of PET plastics, with a focus on the processes from production to disposal in 12 regions (covering 41 countries) in 2020. By constructing 13 scenarios and analyzing the development trajectory of PET plastics from 2020 to 2030, this study provides scientific evidence and specific strategies for waste reduction and emission reduction measures in the PET industry. Overall, in 2020, the 12 regions (41 countries) consumed 7297.7 kilotons (kt) of virgin PET resin and 1189.4 kt of recycled PET resin; 23% of plastic waste was manufactured into recycled PET materials, 42% went to landfills, and 35% was incinerated. In 2020, the entire PET plastic supply chain emitted approximately 534.6 million tons (Mt) of carbon dioxide equivalent per year, with production emissions accounting for 46.1%, manufacturing stage emissions accounting for 44.7%, and waste treatment stage emissions accounting for 9.2%. Research indicates that under a scenario of controlled demand, resource efficiency improvement and emission reduction are the most effective, potentially reducing carbon emissions by up to 40%.

Discovery and characterization of two novel polyethylene terephthalate hydrolases: One from a bacterium identified in human feces and one from the Streptomyces genus

Polyethylene terephthalate (PET) is widely used for various industrial applications. However, owing to its extremely slow breakdown rate, PET accumulates as plastic trash, which negatively affects the environment and human health. Here, we report two novel PET hydrolases: PpPETase from Pseudomonas paralcaligenes MRCP1333, identified in human feces, and ScPETase from Streptomyces calvus DSM 41452. These two enzymes can decompose various PET materials, including semicrystalline PET powders (Cry-PET) and low-crystallinity PET films (gf-PET). By structure-guided engineering, two variants, PpPETaseY239R/F244G/Y250G and ScPETaseA212C/T249C/N195H/N243K were obtained that decompose Cry-PET 3.1- and 1.9-fold faster than their wild-type enzymes, respectively. The co-expression of ScPETase and mono-(2-hydroxyethyl) terephthalate hydrolase from Ideonella sakaiensis (IsMHETase) resulted in 1.4-fold more degradation than the single enzyme system. This engineered strain degraded Cry-PET and gf-PET by more than 40% and 6%, respectively, after 30 d. The concentrations of terephthalic acid (TPA) in the Cry-PET and gf-PET degradation products were 37.7% and 25.6%, respectively. The discovery of these two novel PET hydrolases provides opportunities to create more powerful biocatalysts for PET biodegradation.

Single Polymer Composites: An Innovative Solution for Lower Limb Prosthetic Sockets

The demand for affordable prostheses, particularly in low- and middle-income countries (LMICs), is significant. Currently, the majority of prosthetic sockets are manufactured using monolithic thermoplastic polymers such as PP (polypropylene), which lack durability, strength, and exhibit creep. Alternatively, they are reinforced with consumptive thermoset resin and expensive composite fillers such as carbon, glass, or Kevlar fibres. However, there are unmet needs that amputees face in obtaining affordable prosthetic sockets, demanding a solution. This study utilises self-reinforced PET (polyethylene terephthalate), an affordable and sustainable composite material, to produce custom-made sockets. Advancing the development of a unique socket manufacturing technique employing a reusable vacuum bag and a purpose-built curing oven, we tested fabricated sockets for maximum strength. Subsequently, a prosthetic device was created and assessed for its performance during ambulation. The mechanical and structural strength of PET materials for sockets reached a maximum strength of 132 MPa and 5686 N. Findings indicate that the material has the potential to serve as a viable substitute for manufacturing functional sockets. Additionally, TOPSIS analysis was conducted to compare the performance index of sockets, considering decision criteria such as material cost, socket weight, and strength. The results showed that PET sockets outperformed other materials in affordability, durability, and strength. The methodology successfully fabricated complex-shaped patient sockets in under two hours. Additionally, walking tests demonstrated that amputees could perform daily activities without interruptions. This research makes significant progress towards realising affordable prostheses for LMICs, aiming to provide patient-specific affordable prostheses tailored for LMICs.

Oscillation rheology, calorimetry and computed tomography: A practical toolkit combination of qualification for real poly(ethylene terephthalate) waste

The conventional qualification methodologies, such as internal viscosity measurement and Melt Flow Index (MFI) tests, which are routinely applied to pristine materials and homogenous waste, are not directly transferrable to the qualification process of plastic mixtures. The current investigation is oriented towards the development of a pragmatic suite of measurements techniques aimed at facilitating the qualification of diverse real polyethylene terephthalate (PET) waste streams. This is primarily achieved through the integration of oscillatory rheology, calorimetry and computed tomography (CT). Samples derived from both selective income (SI) and sorting residue (SR) of a manual selective waste sorting plant are included, along with an examination of PET material originating from refuse-derived fuel (RDF). To establish references for comparison, manually collected bottles with (BCL) and without (B) caps and labels are employed, leveraging their known composition and purity. Calorimetry reveals that the glass transition temperature (Tg) is the most sensitive parameter for tracking the structural and compositional changes in waste PET-based streams. The utilization of temperature sweep test in rheology for determining the melting temperature (Tm) proves advantageous, offering a significantly shorter measurement time (∼1:24) compared to calorimetry. Importantly, this approach yields the Tm of the genuine composition rather than individual components. Detection of metal content contaminations in PET waste streams is made possible through CT, while frequency tests in rheological measurements demonstrate effectiveness in discerning their effects.

Breathable and wearable graphene/waterborne polyurethane coated regenerated polyethylene terephthalate fabrics for motion sensing and thermal therapy

The functional utilization of recycled polymers has emerged as a current prominent and timely subject. Flexible wearable devices with high sensitivity to conductivity have garnered significant attention in the fields of human healthcare monitoring and personal heat management. One significant obstacle that needs to be addressed is the simultaneous maintenance of both sensing functionality and durability in composite fabrics. In this paper, a collection of durable, breathable, and flexible smart fabric was produced using the scratch coating method. The fabrics were created by utilizing a regenerated polyethylene terephthalate fabric as a base material, incorporating graphene microsheets (G) as a conductive agent, and applying a waterborne polyurethane layer as a surface protective coating. Furthermore, an investigation was conducted to assess their sensing performance and electrothermal performance. The composite fabric exhibits significant advantages in terms of high conductivity (592 S/m), wide strain range, high sensitivity (Gauge factor = 6.04) and fantabulous dynamic stability (2000 cycles) at a mass ratio of Graphene/WPU loading of 8:2. These sensors were successfully utilized to monitor various degrees of real-time human body movements, ranging from significant deformation bending of elbows to slight deformation swallowing. Furthermore, the sensors also exhibit a significant electric heating effect. Specifically, when a voltage of 10 V is applied, the sensors can reach a steady state temperature of 53.3 °C within a mere 30 s. This discovery holds potential for the development of wearable heaters that can be used for on-demand thermal therapy, functional protective clothing, and medical electric heating wearables.

Apartment with Acoustics Environment Approach in Center Jakarta

Environmental acoustics have an important architectural role that has a major influence on the productivity, health and sustainability of cities. living and proximity to the workplace have become essential needs for workers and entrepreneurs in today’s era. As many still work using the hybrid system, where workers require a comfortable living space as well as a comfortable workspace to support productivity, meetings and work can be done in the same place. SOHO apartments provide a solution to this problem, but they are prone to acoustic issues due to their open plan and loft concepts. The large volume of space requires special treatment, especially in terms of reverberation time. Excessive reverberation time can disrupt the productivity of residents and workers. A quiet space is needed to support these activities. This study aims to explain how environmental acoustics can improve the quality of a room and increase productivity and healthy through the application of acoustic absorbent material. However, the use of absorbent material is not very good for the environment if its use is not appropriate, therefore the selection of absorbent material must be analyzed carefully, so that what is obtained is PET (Polyethylene Terephthalate) material which supports all aspects of the SOHO apartment’s space needs and also material recycling up to 90%-99% which is good for sustainability. This study uses a combination method of observation and precedent studies. The results of this research involve the application of parameters to address acoustic issues in SOHO apartments and improve the acoustic quality of the space.

Modification of Agro-wastes Reinforced onto the PET Fabric for Decolorisation of Palm Oil Mill Effluent

The abundance of agricultural wastes from various industrialized processes has become one of the significant contributors to water pollution, particularly in the color of effluents from industrial-based palm oil mills. Inventively, this research focused on three different agro-wastes: pineapple leaves (PL), rice straw (RS), and empty fruit bunch (EFB) reinforced onto PET fabric composite and its decolorization performances by using palm oil mill final effluent discharged (POME-FED). The calcinated agro wastes/polyvinylidene fluoride (PVDF) reinforced onto the polyethylene terephthalate (PET) fabrics were prepared by using the dip-coating technique and characterized via Scanning Electron Microscopy (SEM-EDS), spectroscopy (FTIR-ATR), turbidity and color of POME-FED. It was found that the calcinated PL/PVDF/Fabric displayed the best performance in the turbidity and decolorization by 12.02 NTU, 760 ADMI, and ~60% color removal efficiency as compared with raw POME-FED (~1800 ADMI). Nevertheless, the decolorization efficiencies of RS/PVDF/Fabric and EFB/PVDF/Fabric had increased by ~37 % and ~49 %, respectively. It shows that the formation of a reinforcing layer on the PET fabric surface has improved the transparency of POME-FED. The SEM micrographs and the change of peaks at regions 1650 cm-1, 1450 cm-1, 1210 cm-1, and 990 cm-1 in composites' spectroscopies demonstrate the different patterns of these calcinated samples are various patterns that impart the strength of the composite fabric surface functionality and hydrophobicity. The reduction of the color value of effluent showed the hydrophobicity of the integrated palm oil waste coated with PET, which enables to trap of the particles in the effluent, thus this composite has potential use in the filtration of water treatment.

Facile Recycling Strategy of Dyed Polyester Waste by Template-Based Synthesis of UiO-66 for Value-Added Transformation into Self-detoxifying Fabrics.

Polyethylene terephthalate (PET) accounts for a significant portion of textile waste, and recycling strategies for this material have attracted much attention. This study proposes a facile and innovative PET recycling method applicable to environmental remediation that involves the conversion of dyed PET fabric waste into a value-added fabric. Herein, a template-based synthesis approach capable of growing a UiO-66 metal-organic framework (MOF) directly on a dyed PET fabric is reported. The advantage of this process lies in its simplicity, where the partial hydrolysis of PET followed by a zirconium chloride treatment results in the successful growth of UiO-66 on a dyed PET fabric with the concurrent removal of the dye without additional steps. The catalytic performance of the UiO-66-grown fabric was evaluated through the degradation of dimethyl 4-nitrophenyl phosphate (DMNP), a nerve agent simulant. The fabric produced by the simple metal treatment (Zr@PEThyd) exhibited excellent DMNP degradation performance with t1/2 = 43.3 min and maintained functional stability after a harsh washing procedure, an outcome attributed to the surface-assisted UiO-66 growth that ensured good bonding stability. The developed process is innovative in that it uses dyed PET waste as a template for the direct growth of UiO-66, simplifying the process without compromising the catalytic functionality. This research provides an informative option for a sustainable textile recycling strategy by transforming dyed PET waste into an advanced self-detoxifying material.

Polyethylene terephthalate bottles with excellent oxygen, water vapor barrier and mechanical performances prepared by injection and blow molding

AbstractIn this work, the oxygen barrier property of polyethylene terephthalate (PET) films was enhanced by optimizing the “active” and “passive” synergistic barrier approaches, that is, integration of high barrier material polyethylene naphthalate (PEN) and oxygen scavengers along with catalyst with PET before biaxially stretching the PET blended films. When the PEN content in the PET blended films reached 50 wt%, the oxygen permeability coefficient was significantly reduced to 0.9687 cc·mil·m−2·day−1·0.1 MPa−1, showing an enhancement of 117.4 times compared to the pure PET film. Furthermore, the water vapor permeability coefficient was reduced to 8.0208 g·mil·m−2·day−1, representing a 45.5% reduction in comparison to the pristine PET film. It also maintained a higher transverse and longitudinal tensile strength (110.5 and 127.2 MPa) than PET film only with oxygen scavengers and catalyst (53.5 and 78.0 MPa). This work presents a viable and practical approach to endow PET materials with simultaneously enhanced oxygen, water barrier performance, and mechanical property.Highlights The OPC of PET film was as low as 0.9687 cc·mil·m−2·day−1·0.1 MPa−1. The “active” and “passive” barrier techniques together reduced the OPC of PET film.

In vitro biomechanics of divot use, and their placement, in orthodontic aligner therapy.

To evaluate biomechanics of an aligner utilizing divots and the effect of their vertical placement on the right maxillary central incisor. An invitro Orthodontic SIMulator (OSIM) was used to test forces and moments generated by aligners incorporating divots. The OSIM arch was scanned to generate a. STL version that was modified to create four models by placing divots on different positions of the right central maxillary incisor: GI - divots on gingival-third of lingual surface and incisal-third of labial surface; GM - divots on gingival-third of lingual surface and middle-third of labial surface; MI - divots on middle-third of lingual surface and incisal-third of labial surface; MM - divots on middle-third of lingual surface and middle-third of labial surface. Aligners (n = 30/model) were fabricated using a 0.75 mm thick polyethylene terephthalate material and Biostar® machine following the manufacturer's recommendations. A one-way MANOVA followed by one-way ANOVA (α = 0.05) was utilized to test effect of models on buccolingual force (Fy) and mesiodistal moment (Mx) at 0.20 mm of lingual displacement of the right maxillary central incisor. Mean Mx for GI (-5.68 ± 7.38 Nmm), GM (3.75 ± 5.54 Nmm), MI (-4.27 ± 1.48 Nmm) and MM (1.96 ± 0.99 Nmm) models showed statistical differences between GI and GM, GI and MM, GM and MI and MI and MM. GI exerted the largest Fy (1.87 ± 0.75 N) followed by GM (1.10 ± 0.47 N), MI (0.70 ± 0.23 N) and MM (0.28 ± 0.08 N) with significant differences between GI and GM, GI and MI, GI and MM and GM and MM models. Vertical divot placement on a right central incisor had a significant effect on aligner biomechanics. Buccolingual forces exerted by models GI, GM and MI were within the range suggested by literature for bodily tooth movement without major root tipping for GM and MI models.

A universal eco-friendly flame retardant strategy for polylactic acid fabrics and other polymer substrates

Various polymer substrates have their particular combustion features, therefore, developing an effective universal flame retardant strategy for various polymer substrates is of great practical importance. Meanwhile, as substitutes for petroleum-based products, bio-based flame retardants and biodegradable polylactic acid (PLA) meet the requirements of sustainable development. In this work, a fully bio-based flame retardant coating (PAGS) was prepared using phytic acid (PA) and guanosine (GS). PAGS was used as a universal flame retardant coatings for polylactic acid (PLA) fabrics and other substrates, including cotton fabrics, polyethylene terephthalate (PET) fabrics, polyamide (PA) fabrics, polyurethane (PU) foams, polyethylene terephthalate (PET) films, and woods. The PAGS-treated substrates were able to self-extinguish and eliminate molten droplets. Similarly, the PAGS coating significantly suppressed the heat release of each substrate. The P-containing free radicals in the gas phase were able to interact with highly reactive H, HO and alkyl radicals, blocking the chain reaction during combustion. The flammable gas density was also diluted by nonflammable gases. The formed continuous porous and dense intumescent char layer hindered heat and oxygen. It is suggested that this work provides a simple and efficient flame retardant strategy for improving the fire safety of various polymer substrates.

Mechanical Property Characterization of Architectural Coated Woven Fabrics Subjected to Freeze–Thaw Cycles

This paper presents experimental investigations into the freeze–thaw response of two common architectural coated woven fabrics. Strip specimens for the tensile tests were exposed to −20 °C for three hours followed by three hours of thaw at ambient temperatures. This was repeated for a maximum of 100 cycles. Afterwards, the residual tensile strength was measured and compared to results achieved for test specimens without prior freeze–thaw cycles. Maximum mean tensile strength reductions of approximately 21% (warp direction) and 19% (weft direction) for probed polytetrafluoroethylene (PTFE)-coated woven glass fiber fabrics were identified, while no remarkable tensile strength deterioration rate was observed for the investigated polyvinyl chloride-coated woven polyethylene terephthalate materials. Overall, the results indicate that freeze–thaw cycles can have a significant deteriorating impact on the mechanical properties of glass-PTFE fabrics.

The Effect of Pore Length on The Mechanical Properties of Vascular Scaffold Due to Systolic Pressure

Tissue replacements are highly limited due to the lack of vascularized tissue in the engineered tissue. Thus, incorporating the vascular scaffold in any injured tissue or organ is critical in the tissue regeneration. As one of elastic tissue in human body, mechanical properties are vital in engineering a vascular scaffold. Besides, interconnected pores and scaffold porosity are among the main considerations in designing the scaffold for allowing the vascularization. Therefore, this study aims to simulate the mechanical properties of three-dimensional (3D) printed vascular scaffold by observing the deformation and elasticity after being applied with the maximum systolic pressure. Scaffolds with three different pore lengths were simulated for compression and tensile analysis by using Finite Element Analysis (FEA) based on polyethylene terephthalate (PET) material’s properties. The findings indicated that effective elastic modulus of the vascular scaffolds varied based on the pore length with shortest pore length gave the highest elasticity, whilst scaffold with the longest pore length gave lowest elasticity. Besides, stress value of compression and tensile analysis for all scaffolds were did not exceed the PET’s yield strength that indicated the designed scaffolds will have high potential for vascular tissue engineering applications.

Supercritical CO2 Assisted Ni-P Electroless Plating of PET Components with Complex 3D Structures

There is an increasing demand of methodologies to metallize complex polymer materials for application in electronics such as wearable devices and robotic products. In various metallization methods, electroless plating is a powerful and promising approach to meet this demand. The present conventional electroless plating requires pretreatment steps to deposit catalyst onto surfaces of polymer materials, which results in damages to their surfaces and also deformation of their shape because of the usage of strong acidic solvents. Furthermore, the adhesion strength between the polymer material and the metal layer is insufficient. To overcome these problems, a catalyzation step using supercritical carbon dioxide (sc-CO2) as the solvent is proposed.[1] The sc-CO2-assisted catalyzation enables a deep impregnation of catalysts into the polymer material without the pretreatment step, and this enhances the adhesive properties of the deposited metal on the polymer. By the sc-CO2-assisted catalyzation, electroless Ni-P plating of polyethylene terephthalate (PET) is realized. [1] Metallization of polymer materials with complex 3D structures is a more attractive topic, but it is widely accepted to be more difficult than film structures. Also, application the electroless plating via sc-CO2-asssited catalyzation to 3D-structured polymer materials remains unexplored. In this presentation, we report Ni-P plating of PET samples having complex 3D structures by the sc-CO2-assisited catalyzation process.A PET based material with a concavo-convex structure was designed and fabricated by the processing machine as shown in Figs. 1(a)–(b). Sc-CO2-assisted catalyzation process was performed in a high pressure reactor[1] containing palladium (II) hexafluoroacetylacetonate (Pd(C5HF6O2)2) as the palladium catalyst source at 70 °C under 15 MPa for 2 h. After the catalyzation process, the reactor was cooled to room temperature while maintaining the pressure in the reactor, and then the pressure in the reactor was reduced to atmospheric pressure. The collected PET sample from the reactor was kept under ambient atmosphere for two weeks, and then it was subjected to electroless Ni-P plating at 70 ℃ for 10 min.Fig. 1(c) shows the PET sample obtained after the sc-CO2-assisted catalyzation process followed by the post-treatment process. The volume of the catalyzed PET sample was scarcely changed. On the other hand, the post-treatment processes performed under the different conditions were found to cause undesired swelling and white turbidity of the PET sample, presumably because of microbubbles derived from residual CO2 in the PET. Fig. 1(d) shows an image of Ni-P successfully metallized on the PET surface. The electrical resistance of the Ni-P/PET material was 8.7 Ω, which is acceptable for electronic device applications. From these results, we concluded that sc-CO2-assisted catalyzation is applicable to metallization of PET materials with complex 3D structures. Reference [1] P.-W. Cheng, C.-Y. Chen, T. Ichibayashi, T.-F.M. Chang, M. Sone, S. Nishimura, J. Supercrit. Fluids 180 (2022) 105455. Figure 1

Synthesis, recovery, and application of environmentally friendly disperse dyes with high light fastness

Dye wastewater has attracted great attention due to high pollution and toxicity which can cause harm to the living environment. It is common for azo-disperse dyes to be used to dye hydrophobic fibers. A reduction clearing method is used to eliminate the dye particles on the fabric after dyeing. However, when azo disperse dyes on the fiber surface are eliminated by the reduction clearing process, this can give rise to an effluent discharge due to the presence of sodium hydrosulfite. The introduction of carboxylic ester groups into dye molecules can effectively avoid this issue. Six novel environmentally friendly alkali-clearable disperse dyes, containing cyano and carboxylic ester groups, were readily synthesized by a diazo coupling reaction with various diazo components. Their dyeing properties on polyethylene terephthalate fabrics were respectively measured and compared with those of commercial reference dyes. It was indicated that some fastness properties of the synthesized dyes on polyethylene terephthalate fabrics after the alkali clearing were improved compared with those of the reference dyes due to the existence of the carboxylic ester group. Moreover, the chromaticity of dye wastewater can be further reduced by recovering hydrolyzed dyes.

Design and optimization of a transparent and flexible MIMO antenna for compact IoT and 5G applications

This work presents an optically transparent and flexible MIMO antenna that features two square patch elements placed in close proximity, aiming to meet the demands of compactness, flexibility, optical transparency, and visual appeal for IoT applications and future 5G wireless communication. The design includes a simple offset fed configuration to achieve the required isolation and impedance matching. It simplifies the process of creating closely spaced transparent MIMO antenna configurations. By optimizing and analyzing this structure, the antenna achieves better isolation and diversity gain performance, even when the patch elements are positioned very close to each other. To achieve optical transparency and flexibility, the antenna uses thin polyethylene terephthalate (PET) material as a substrate, which is a thermoplastic polymer resin from the polyester family. The wired metal mesh parameters for conducting parts of the MIMO antenna and offset position of the feed are carefully optimized to achieve required optical transparency, isolation, impedance matching and radiation performance without any complex decoupling or impedance matching network.

Analysis of the Influence of PET and Glass Packaging Waste Materials on the Physical and Mechanical Properties of Cementitious Composites

The limited availability of natural resources, such as sand, and the need to reduce CO2 emissions, which are produced in large quantities in the production of binding materials, indicate the need to look for alternative raw materials used in construction materials. At the same time, there is a strong need to utilise waste packaging materials, the global production of which is constantly increasing. This work aims to investigate the possibility of using recycled polyethylene terephthalate (PET), utilised as a partial substitute for fine aggregate, and waste glass, implemented as powder, serving as a partial substitute for cement in the manufacturing of the cementitious composites. An experimental study was carried out to evaluate the physical and mechanical properties of the resultant cementitious composites. The incorporated PET aggregate comprised 0%, 5%, and 10% by volume of silica sand and 0%, 10%, and 20% glass powder by weight of cement. The addition of waste raw materials augmented the flow of fresh mortars, predominantly subsequent to the introduction of PET recyclate. The deployment of artificial aggregate in mortars induces a decrease in the volumetric density. Concurrently, the mechanical properties of mortars enriched with waste materials exhibited a reduction, in terms of both compressive and flexural strength, with the detriment escalating in conjunction with the content of waste raw materials. An analysis of statistical significance of effects, grounded in an analysis of variance, is delineated within this document, pinpointing the quantities of waste raw materials that can be assimilated in mortars without inducing a substantial deterioration of strength properties. Through studies on phase composition, it has been demonstrated that the utilised glass waste, possessing a grain size analogous to cement, exhibited poor pozzolanic properties. The test results indicate that it is possible to partially replace cement with glass powder, up to 10%, and fine aggregate with PET waste, up to 5%, without a significant reduction in the mechanical properties of the material.

Enhancing oil repellency of electron beam‐grafted polyethylene terephthalate fabric with 2‐(perfluorohexyl) ethyl acrylate monomer via pre‐irradiation

AbstractElectron beam (EB)‐induced graft polymerization is advantageous for the surface modification of fabrics. We investigated the effect of monomer concentration and the addition of alkyl groups on the oil repellency of polyethylene terephthalate (PET) fabrics treated with monomers containing fluoroalkyl groups through EB‐induced graft polymerization via pre‐irradiation. We use 2‐(perfluorohexyl) ethyl acrylate (FEA) and stearyl acrylate (SA(C18)) with long alkyl chains as vinyl monomers to induce reaction with radicals generated from EB irradiation. The weight gain and surface morphology of the PET fabrics change with the FEA monomer concentration. The uniformity of the EB‐grafted PET fabric surface is determined at low monomer solution concentrations. Results of X‐ray photoelectron spectroscopy analysis show that adding 0.1 mol/L of FEA monomer to the EB‐grafted PET fabric yields the highest dodecane contact angle of 93.4° and a surface fluorine concentration of 39.8%. The addition of SA(C18) monomer to the FEA monomer decreases the dodecane contact angle by 77.5° and yields a surface fluorine concentration of 19.1%. EB graft polymerization via pre‐irradiation results in a uniformly treated surface, and stable oil repellency is achieved when using solely the FEA monomer at a lower monomer concentration than that used in a similar irradiation method reportedly previously.