Acrylonitrile Butadiene Styrene Research Articles

Additive Manufacturing of Waste Electrical and Electronic Equipment (WEEE) Produced From Acrylonitrile Butadiene Styrene (ABS)

Objective: To evaluate the feasibility of producing recycled acrylonitrile-butadiene-styrene (r-ABS) filaments from waste electrical and electronic equipment (W EEE) casings, specifically discarded monitors and televisions, and to compare their properties with those of virgin ABS. Theoretical Framework: The research was based on a literature review of additive manufacturing, WEEE recycling, and the thermal, mechanical, rheological, and microscopic characterizations of recycled polymers, with an emphasis on fused deposition modeling (FDM). Method: WEEE casings were collected and mechanically recycled to produce r-ABS filaments. These filaments were characterized and compared with virgin ABS filaments using infrared spectroscopy (FTIR), thermal analyses (TGA and DSC), rheological, mechanical, and microscopic evaluations. Results and Conclusion: The results indicated that r-ABS filaments exhibit properties comparable to those of virgin ABS. FTIR analysis revealed the presence of the main functional groups of ABS in the recycled samples. Thermal analysis showed similar behavior between the recycled and virgin materials, with a single thermal decomposition event. Rheological analysis demonstrated that r-ABS possesses viscoelastic properties suitable for the FDM process, and mechanical characterization showed that r-ABS exhibited tensile strength close to virgin ABS. Microscopic analysis revealed good layer adhesion and a low number of voids, factors that contribute to the quality of the printed objects. Research Implications: This study contributes to the valorization of polymeric waste, promoting the use of recycled materials in additive manufacturing processes, which can benefit both the environment and the 3D printing industry. Originality/Value: The research addresses a topic still underexplored in the literature, especially concerning the recycling of WEEE casings for the production of ABS filaments.

Prediction of Acrylonitrile–Butadiene–Styrene Mechanical Properties through Compressed-Sensing Techniques

Prediction of Acrylonitrile–Butadiene–Styrene Mechanical Properties through Compressed-Sensing Techniques

A study of crashworthiness performance in thin‐walled multi‐cell tubes 3D‐printed from different polymers

AbstractMulticellular, thin‐walled impact tubes have been intensely studied and used in various engineering fields in recent years due to their lightweight, high performance, ease of application, superior energy absorption, and stable deformation characteristics. In this study, energy absorption, crashworthiness performances, and deformation properties of thin‐walled structures manufactured from polylactic acid (PLA+) and acrylonitrile butadiene styrene (ABS) using fused deposition modeling (FDM) technology were compared under quasi‐static axial compression. Thin‐walled structures consist of multicellular tubes connected by concentric corner‐edge connections with square and hexagonal cross‐sections. Experimental testing outcomes indicate that the energy absorption capacity increases with increasing the number of corners in multicellular structures. The tubes with square wall‐to‐wall (S‐WW) and hexagonal wall‐to‐wall (H‐WW) cross‐sections exhibit superior crashworthiness performance compared to other cross‐sections. Based on the experimental results, the absorbed energy by WW patterned PLA+ square tubes are 19%, 7%, and 46% more than that of wall‐to‐corner (WC), corner‐to‐wall (CW), and corner‐to‐corner (CC) patterned tubes, respectively, while it is 11%, 19%, and 80% more in hexagonal cross‐section tubes, respectively. This study provides an informative reference for easier applicability of multicellular energy‐absorbing structures with 3D‐print and the design of corner‐edge connections of internal connections in multicellular structures.

Comprehensive Study of Mechanical, Electrical and Biological Properties of Conductive Polymer Composites for Medical Applications through Additive Manufacturing

Conductive polymer composites are commonly present in flexible electrodes for neural interfaces, implantable sensors, and aerospace applications. Fused filament fabrication (FFF) is a widely used additive manufacturing technology, where conductive filaments frequently contain carbon-based fillers. In this study, the static and dynamic mechanical properties and the electrical properties (resistance, signal transmission, resistance measurements during cyclic tensile, bending and temperature tests) were investigated for polylactic acid (PLA)-based, acrylonitrile butadiene styrene (ABS)-based, thermoplastic polyurethane (TPU)-based, and polyamide (PA)-based conductive filaments with carbon-based additives. Scanning electron microscopy (SEM) was implemented to evaluate the results. Cytotoxicity measurements were performed. The conductive ABS specimens have a high gauge factor between 0.2% and 1.0% strain. All tested materials, except the PA-based conductive composite, are suitable for low-voltage applications such as 3D-printed EEG and EMG sensors. ABS-based and TPU-based conductive composites are promising raw materials suitable for temperature measuring and medical applications.

Tensile, flexural and fatigue properties of different thermoplastic nanocomposites: experimental investigation and ANN prediction of the fatigue life

ABSTRACT Polymer-based nanocomposites have received immense attention in industrial applications as their mechanical properties are superior to traditional polymer composites. In this study, three different thermoplastic polymers, namely (a) polypropylene (PP), (b) acrylonitrile butadiene styrene (ABS), and (c) high-density polyethylene (HDPE) were used for the purpose of engineering different nanoclay-based nanocomposites. The blending of the polymer was performed by varying the nanoclay weight percentage (0.5, 1, 3, and 5 wt.%) using a twin-screw extruder. The different nanocomposites were fabricated through injection moulding process. The composites were fabricated by considering the 90 bars of injection pressure, 60 mm/s of injection speed, and 25 sec of cooling time. The effect of nanoclay inclusion on the mechanical properties of the nanocomposites was evaluated and compared with the neat polymer. The effect of nanoclay inclusion was studied through morphological analysis of the fractured tested specimens. The tensile strength and modulus of ABS-nanoclay (5%) exhibited an enhancement of 30.95% and 35%, respectively as compared to the pure ABS. Meanwhile, the fatigue life revealed an improvement of 66.01%. The tensile strength and modulus of the ABS/nanoclay (5%) were achieved as 38.6 MPa and 1.44 GPa.

Investigation of compressive strength of primitive geometries printed through the fused deposition modeling technique with different path patterns

Fused Deposition Modeling (FDM) is a material-extrusion-based technique used primarily for rapid prototyping and sometimes for an actual servicing part. In the FDM technique, input parent materials are commercial polymers. FDM also has some manufacturing parameters, and the raster pattern significantly affects the mechanical performance of the FDM products. Due to its intrinsic nature, Acrylonitrile Butadiene Styrene (ABS) is widely used in many industries, such as automobiles, medicine, etc. Producing the primitive geometry and selecting the proper infill pattern is challenging. Therefore, the current research paper investigates the effects of various infill patterns on the compressive performance of the three geometries (sphere, 3-side, and 4-side pyramids) printed through the FDM technique out of ABS material. The compressive experiments were conducted on the printed samples and load-displacement curves were evaluated. The results reveal that the concentrate path pattern in the sphere samples has the highest compressive failure load (40127 N). Also, the compressive failure loads in the 3-side and 4-side pyramids fabricated with a 45°/−45° raster pattern are 30444 N and 44396 N, respectively. Finally, comprehensive discussions about the obtained results are stated.

From e-waste to living space: Flame retardants contaminating household items add to concern about plastic recycling

Brominated flame retardants (BFRs) and organophosphate flame retardants (OPFRs) are commonly used in electric and electronic products in high concentrations to prevent or retard fire. Health concerns related to flame retardants (FRs) include carcinogenicity, endocrine disruption, neurotoxicity, and reproductive and developmental toxicity. Globally, a lack of transparency related to chemicals in products and limited restrictions on use of FRs in electronics have led to widespread use and dissemination of harmful FRs. Despite the lack of transparency and restrictions, plastics from electronics are often recycled and can be incorporated in household items that do not require flame retardancy, resulting in potentially high and unnecessary exposure. This study sought to determine whether black plastic household products sold on the U.S. market contained emerging and phased-out FRs and whether polymer type was predictive of contamination. A total of 203 products were screened for bromine (Br), and products containing >50 ppm Br were analyzed for BFRs, OPFRs, and plastic polymers (e.g. acrylonitrile butadiene styrene, high impact polystyrene, polypropylene). FRs were found in 85% of analyzed products, with total FR concentrations ranging up to 22,800 mg/kg. FRs detected include the restricted compound deca-BDE, which was used widely in electronics casings, as well as its replacements decabromodiphenyl ethane (DBDPE) and 2,4,6-Tris(2,4,6-tribromophenoxy)-1,3,5-triazine (TBPP-TAZ) along with associated compound 2,4,6-tribromophenol (2,4,6-TBP), recently detected in breast milk. Plastic typically used in electronics (styrene-based) contained significantly higher levels of ∑FRs than plastics less typically used for electronics (polypropylene and nylon). Estimation of exposure to BDE-209 from contaminated kitchen utensils indicated users would have a median intake of 34,700 ng/day, exceeding estimates for intake from dust and diet. The detection of FRs in collected household products indicates that recycling, without the necessary transparency and restrictions to ensure safety, is resulting in unexpected exposure to toxic flame retardants in household items.

Potential of Non-Contact Dynamic Response Measurements for Predicting Small Size or Hidden Damages in Highly Damped Structures

Vibration-based structural health monitoring (SHM) is essential for evaluating structural integrity. Traditional methods using contact vibration sensors like accelerometers have limitations in accessibility, coverage, and impact on structural dynamics. Recent digital advancements offer new solutions through high-speed camera-based measurements. This study explores how camera settings (speed and resolution) influence the accuracy of dynamic response measurements for detecting small cracks in damped cantilever beams. Different beam thicknesses affect damping, altering dynamic response parameters such as frequency and amplitude, which are crucial for damage quantification. Experiments were conducted on 3D-printed Acrylonitrile Butadiene Styrene (ABS) cantilever beams with varying crack depth ratios from 0% to 60% of the beam thickness. The study utilised the Canny edge detection technique and Fast Fourier Transform to analyse vibration behaviour captured by cameras at different settings. The results show an optimal set of camera resolutions and frame rates for accurately capturing dynamic responses. Empirical models based on four image resolutions were validated against experimental data, achieving over 98% accuracy for predicting the natural frequency and around 90% for resonance amplitude. The optimal frame rate for measuring natural frequency and amplitude was found to be 2.4 times the beam’s natural frequency. The findings provide a method for damage assessment by establishing a relationship between crack depth, beam thickness, and damping ratio.

Exploring the strain rate influence on shear yield behavior of acrylonitrile-butadiene-styrene: Experimental and numerical study

Most experimental and numerical studies are limited to examining the effect of strain rate on the compressive and tensile yield behavior of Acrylonitrile-Butadiene-Styrene (ABS), an amorphous material of significant industrial relevance, rather than its shear yield behavior; therefore, this study is dedicated to addressing this notable gap in the literature by exploring the effect of strain rate on the shear yield behavior of ABS. To this end, shear tests were carried out using the Wyoming version of the Iosipescu (V-notched) shear test fixture at five distinct loading rates, ranging from 5 × 10−3 to 1 × 101 mm/s, which correspond to strain rates between 5.5 × 10−4 s−1 and 7 × 10−1 s−1. Shear strain distributions in the specimens were measured using the Digital Image Correlation (DIC) technique. The shear test results not only revealed a substantial increase in the shear yield strength of ABS with increasing strain rate, but also demonstrated that the shear yield strength of ABS is more sensitive to strain rate than its compressive and tensile yield strengths. The findings of the study also suggested that using shear-tension test data pairs at the same strain rates is more effective for determining the hydrostatic pressure sensitivity parameter than using tension-compression and shear-compression test data pairs. The experimental results were validated against numerical predictions obtained through finite element analyses employing an elastic-viscoplastic constitutive model, which comprehensively accounted for non-linear material properties, geometric complexities, and non-linearities arising from boundary contacts.

Design of Mold Flipper in an Effort to Improve The Efficiency of Mold Maintenance Process

Molding is a production process by forming raw materials using a rigid frame or model used in the manufacturing industry to mold materials called a mold. Injection molding is a technique in the manufacturing industry for molding thermoplastic materials. Thermoplasctic materials commonly molded with Injection Molding techniques are Polystyrene, Acrylonitrile Butadiene Styrene (ABS), PMMA (Polymethyl Methacrylatic) and others. The purpose of this research is to design and build a flipper molding tool for an easier and more efficient mold maintenance process. This research uses descriptive methods. Data is taken through direct observation and through reference books both from companies and websites and journals related to the report material. The data obtained was analyzed using descriptive analysis. it is found that the material used in the work is Carbon Steel (S45C). The process of making Flipper Clamps Mold has several stages, namely the Design Making Process, Material Selection Process, Cutting Process, Milling Process, Grinding Process, Drilling Process, Welding Process, and Assembly Process. With this Flipper Clamping tool, it is hoped that it can make it easier for operators to maintain and repair molds, because the previous mechanism requires two operators to flip molds that weigh more than 200 kg, now they only need to flip by turning the lever of this tool.

Experimental investigation and optimization for after-impact residual strength of a novel gradient corrugated structure

A novel structure based on a gradient corrugated architecture is introduced, and its after-impact residual strength is numerically and experimentally investigated. Low-velocity impact (LVI) and compression after impact (CAI) tests are conducted on designed specimens made of acrylonitrile butadiene styrene (ABS). The experiments reveal that the penetration depth increases linearly with increase in impact energy while the residual strength does not follow the same trend and its degradation rate is decreasing which implies that the structure tends to maintain its strength. A numerical model is developed to simulate the impact and after-impact response of structures with the error range of 2∼15 % for penetration depth values of LVI and less than 5 % error for the residual strength of CAI in comparison with experimental results. In order to maximize the after-impact tolerability, the structural architecture is optimized and realized that trapezoidal cells with decreasing gradient offer the highest specific strength. The sensitivity of the proposed structure to the impact location, with a higher average residual specific resistance, is lower than similar optimized configurations presented in literature.

The Effect of Acrylonitrile Butadiene Styrene (ABS) and Polypropylene (PP) Microplastics on Ulva lactuca L. and Ceramium diaphanum R. Algal Growth

The goal of this study was to determine the effects of acrylonitrile butadiene styrene and polypropylene microplastics as two typical classes for microplastic pollution on algal growth, lipids, carbohydrates, chlorophyll-a and total carotenoid content of Ulva lactuca L. and Ceramium diaphanum R. collected from the Gulf coast of Izmir province. The results demonstrate that ABS-MPs had no statistical effect (P>0.05) on the various physiological parameters of U. lactuca macroalgae after 5 days of exposure, except for the total carbohydrate and lipid concentration. The chl-a value of C. diaphanum was considerably increased under the low concentration of ABS (25 mg L-1), increasing by 81.56% compared with the control while the amount of chl-a decreases (32.05%) in parallel with the increasing concentration of PP-MPs. Laboratory incubation experiments showed that MPs affect relative growth rate, pigments efficiency or carbohydrate content of C. diaphanum until reaching an extremely high concentration (100 mg L-1), indicating a high tolerance to MPs. The results showed that two macroalgae species, especially U. lactuca, were not highly affected at low MPs concentrations under laboratory conditions which were much higher than the levels of environmentally relevant concentrations.

Closed-loop circular economy in ‘upcycled’ acrylonitrile–butadiene–styrene vitrimer

Today, the issue of plastic waste pollution has reached unprecedented levels. The increasing production of plastics, combined with a decreasing rate of recycling, has significantly worsened this problem in recent years. While a wide range of plastics are manufactured, thermoplastics are a type that can be recycled relatively easily. However, recycled thermoplastics often have lower mechanical properties compared to new ones. Considering this challenge, making thermoplastics recyclable could revolutionize the recycling process and represent a major advancement towards establishing a circular economy for plastics. In this study, virgin acrylonitrile–butadiene–styrene (ABS) was transformed into a vitrimer through reactive melt extrusion using a bio-derived crosslinker containing dynamic imine linkages. This crosslinker results in a dynamic network, in the melt, as observed from the higher gel fraction and imparts recyclability to the resulting ABS vitrimer, which exhibits higher yield strength (by 15%) and Young’s modulus (by 19%). Remarkably, the mechanical and thermal properties of the vitrimer remain largely unchanged even after undergoing five cycles of reprocessing. In addition, the resulting vitrimer is dimensionally stable as inferred from creep studies and shows rapid stress relaxation at higher temperature following Arrhenius behaviour. The electron paramagnetic resonance (EPR) spectra were captured at room temperature for both ABS and its vitrimer. The difference in singlet band intensities in the spectra begins to suggest that the vitrimer is more stable post multiple recycling.While this research focused on virgin ABS, the approach outlined in the study has the potential to be applied to post-consumer recycled (PCR) ABS. This could introduce recyclability to PCR ABS and pave the way for a closed-loop circular economy for ABS plastics.

METHODS FOR MITIGATION OF GEOMETRIC DEFECTS GENERATED DURING POLYMER INJECTION MOLDING

Injection molding is one of the most used processes in the polymer parts forming industry, which consists of raising the temperature of a polymeric material to its melting point and introducing it under pressure into the cavity of a mold where it is It will cool to a suitable temperature so that the pieces can be extracted without deforming. This article presents a review of the state of the art of scientific works that state techniques, methods and commercial software, used to analyze, understand and in some cases mitigate failures in the polymer injection process, which will reduce cycle times and production costs. Likewise, during the search, the polymers were delimited: polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET) and for thermostables, acrylonitrile butadiene styrene (ABS), since they are the ones that showed the most cases with failures in the injection molding process. An overview of the use of methods that can be used to analyze the parameters that affect the quality of formed parts is also shown, such as Analysis of Variance (ANOVA), Artificial Neural Networks (ANN), Taguchi, Response Surface Methodology (RSM). It is also presented which are the Finite Element Analysis (FEA) and computer-aided engineering (CAE) software that stand out the most in their use to better understand the physical phenomena that occur during the injection molding process.

Experimental and theoretical research on deformation monitoring of distributed piezoelectric inclinometer tube

To improve horizontal displacement monitoring in geotechnical engineering, researchers have focused on developing distributed, automated, and cost-effective inclinometers capable of long-term monitoring. However, existing technologies cannot fully satisfy these requirements. This study proposes a novel piezoelectric inclinometer tube that incorporates a sensor-enabled piezoelectric geocable (SPGC), which was mounted along the surfaces of three tubes made of different materials. The distributed strain along the inclinometer tube was measured using the impedance–strain effect of the SPGC, and a deflection curve was obtained. The results of the failure test showed that the piezoelectric inclinometer tube remained within its measurement range before breaking. Furthermore, the placement of the SPGC on the outer surface of the tube demonstrated superior monitoring effectiveness under bending deformation, providing qualitative insights into the deformation and fracture behavior of the tube. Loading and unloading tests demonstrated excellent reproducibility of strain in the piezoelectric inclinometer tube. Among the tested materials, the inclinometer tube made of acrylonitrile butadiene styrene exhibited acceptable elasticity, large bending displacement, and a high strain transfer rate, making it ideal for monitoring significant deformations in rock and soil. A linear calibration equation was established for the normalized impedance change–strain relationship of the piezoelectric inclinometer tube through calibration tests. Furthermore, a theoretical model was derived to convert the normalized impedance change to the deflection of the piezoelectric inclinometer tube using the finite difference method. Theoretical and experimental values were significantly consistent, with strain and deflection measurement accuracies of 10 με and 0.1 mm, respectively, and an average calculation error of less than 4 %. These results are expected to improve the distributed monitoring of horizontal displacement in rock and soil.

Microplastic removal and risk assessment framework in a constructed wetland for the treatment of combined sewer overflows

Combined sewer overflows (CSOs) release a significant amount of pollutants, including microplastics (MPs), due to the discharge of untreated water into receiving water bodies. Constructed Wetlands (CWs) offer a promising strategy for CSO treatment and have recently attracted attention as a potential solution for MP mitigation. Nevertheless, limited research on MP dynamics within CSO events and MP removal performance in full-scale CW systems poses a barrier to this frontier of application. This research aims to address both these knowledge gaps, representing the first investigation of a multi-stage CSO-CW for MP removal. The study presents one year of seasonal data from the CSO-CW upstream of the WWTP in Carimate (Italy), evaluating the correlation of MP abundance with different water quality/quantity parameters and associated ecological risks. The results show a clear trend in MP abundance, which increases with rainfall intensity. The strong correlation between MP concentration, flow rate, and total suspended solids (TSS) validates the first flush phenomenon hypothesis and its impact on MP release during CSOs. Chemical characterization identifies acrylonitrile-butadiene-styrene (ABS), polyethylene (PE), and polypropylene (PP) as predominant polymers. The first vertical subsurface flow (VF) stage showed removal rates ranging from 40 % to 77 %. However, the unexpected increase in MP concentrations after the second free water surface (FWS) stage suggests the stochasticity of CSO events and the different hydraulic characteristics of the CW units have diverse effects on MP retention. These data confirm filtration as the main retention mechanism for MP within CW systems. The MP ecological risk assessment indicates a high-risk category for most of the water samples, mainly related to the frequent presence of ABS fragments. The results contribute to the current understanding of MPs released by CSOs and provide insights into the performance of different treatment units within a large-scale CSO-CW system, suggesting the requirement for further attention.

Sand blasting for hydrophobic surface generation in polymers: Experimental and machine learning approaches

Wettability is a crucial surface feature of polymers due to their numerous interaction-destined applications. This study focuses on the application of sand blasting process for investigating the wettability of polymeric materials to produce hydrophobic behavior. Four different polymeric materials, Acrylonitrile Butadiene Styrene (ABS), Poly(methyl methacrylate) (PMMA), Polypropylene (PP), and Polycarbonate (PC) underwent sand blasting with varying process parameters, following a comprehensive plan for the design of experiments. Subsequent analyses included surface roughness measurement and wettability tests, supplemented by scanning electron and confocal microscopy observations to gain deeper insights into the blasted surfaces. A predictive model based on a machine learning algorithm was developed using the backpropagation technique to correlate the surface treatment parameters to surface roughness and wettability indexes. From the experimental results sand blasting proved to be efficient in creating hydrophobic surfaces on all the tested materials. The developed neural network demonstrated high fitting degrees between the predicted and measured values. ABS exhibited the most hydrophobic behavior and emerged as a strong candidate for further investigations.

Structural investigation of wood-inspired cell wall geometries using additive manufacturing: Compression testing and finite element analysis validation

Mechanical properties of wood-inspired cell wall geometries were considered through compression testing and Finite Element Analysis (FEA) with ANSYS simulation. Six models, including earlywood, latewood, and various array configurations, were fabricated via 3D printing using acrylonitrile butadiene styrene (ABS) filament. Compression tests highlighted the annual ring model’s robustness, exhibiting a maximum load of 12707 MPa, while the 4×3 matrix displayed the lowest strength at 4247 MPa. Shifting rows led to reduced strength, which was particularly evident in vertical prints. An analysis of variance revealed significant differences in mechanical properties. Discrepancies between experimental tests and FEA results ranged from -45.9% to 35.2%. Earlywood exhibited a maximum deformation of 2.6 mm, whereas latewood showed lower deformation, indicating geometry’s influence on material behavior. Mesh quality remained consistent, ensuring dependable simulation outcomes. These findings underscore the pivotal role of geometry in compression resistance, laying the groundwork for future studies on wood densification mechanisms and the development of customized wood composites.

Enhancing High-Temperature Performance of Flexible Pavement with Plastic-Modified Asphalt.

Previous studies indicate that traditional asphalt mixtures lack the ability to withstand the stresses caused by heavy traffic volumes under high temperatures. To enhance the rutting resistance of flexible pavement under high levels of temperature and loading, extensive laboratory experiments were carried out. A 60/70 grade bitumen was used as a neat sample for comparison. The study introduced three distinct polymers, polypropylene (PP), low-density polyethylene (LDPE), and acrylonitrile butadiene styrene (ABS), at varying concentrations by weight into the neat bitumen. Initially, conventional tests were performed to evaluate the conventional properties of both the neat and modified bitumen, while aggregate tests assessed the mechanical properties of the aggregates. Subsequently, a Marshall mix design was performed to determine the optimum bitumen content (OBC) in the asphalt mixture. Finally, wheel-tracking tests were performed under a specific load and temperature to investigate the rutting behavior of the modified asphalt mixtures. The results of this comprehensive study revealed that the modified asphalt mixtures displayed improved resistance to rutting compared to the neat asphalt mixture. Furthermore, it was also observed that the LDPE exhibited a superior performance against rutting, followed by the PP and ABS. At polymer contents of 3%, 5%, and 7%, the LDPE achieved reductions in rut depth of 13%, 24%, and 33%, respectively, outperforming both PP- and ABS-modified asphalt. These findings not only enhance our understanding of asphalt behavior under diverse conditions but also highlight the potential of plastic-modified asphalt as an effective solution for mitigating rutting problems in road pavements. By incorporating plastic modifiers into asphalt mixtures, this approach aligns with the principles of sustainable construction by reducing plastic waste while improving pavement durability and performance.

Robust flexible hollow racetrack-shaped terahertz waveguide with single-polarization single-mode and low-loss by plasma aided hot-pressing method

A flexible single-polarization single-mode (SPSM) polymer/Ag-coated hollow waveguide with a racetrack-shaped cross-section was designed and prepared using a simple hot-pressing method and plasma treatment. The waveguide structural parameters were numerically optimized using the finite element method and the SPSM transmission can be achieved in a high birefringent (>0.8) hollow racetrack-shaped waveguide (HRW). The racetrack-like waveguides were facilely prepared by hot-pressing commercially available circular acrylonitrile butadiene styrene (ABS) and poly-ether-ether-ketone (PEEK) tubing, followed by plasma treatment and silver-plating. The HRW samples with a length of 40 cm were prepared, with a straight transmission loss of 1.74 and 1.68 dB/m at 0.1 THz, respectively, and the polarization degree is 99.9 %. When bent for 120° at a 10 cm radius or twisted by 90°, the waveguide samples have additional losses less than 0.22 and 0.14 dB/m, respectively, while the polarization degrees keep almost unchanged. After 200 h hydrothermal aging (85 RH%, 85 ℃) and 20 times high (85 ℃)/low (−40 ℃) temperature tests, the loss increase is less than 0.14 dB/m and the polarization degree remains unaffected. The HRW could be used in practice as a competitive substitute for traditional rectangular metal waveguides due to its high SPSM performance, lightweight, robustness, flexibility, and easy fabrication.