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At present, research on the electrostatic separation of polymers is primarily concentrated in the WEEE field, with limited studies addressing the electrostatic separation of vehicle polymers. In this study, tribo-charging separation of PA66/PP (modified)/PE three-component vehicle polymer mixed particles was investigated using a spiral tube tribo-charged separation device. Firstly, a force model of particle movement in the spiral tube was established, and the theoretical analysis determined that the critical rotational speed of particle centrifugal movement is 70 rpm. Secondly, the optimal charging parameters were determined by single-factor experiments and orthogonal experiments, and the effect of the blanking baffle on the particle charging was also investigated. Finally, high-voltage electrostatic separation simulations and experiments were carried out, achieving separation purities of 92.8% for PA66, 80.7% for PP (modified), and 86.6% for PE, respectively. Results provide both theoretical and experimental reference for one-pass electrostatic separation of three kinds of plastic particles by spiral tube turbo-charged separation device. Highlights * Separation of vehicle polymers is crucial for its high-value-added recycling. * A spiral tube tribo-electrostatic separation device is developed. * The critical rotational speed of particle centrifugal movement is analyzed. * The influence of the blanking baffle on the particle charge is investigated. KEYWORDS end-of-life vehicles, polymer particles, spiral tube, tribo-charging separation, 1 | INTRODUCTION According to the data of the International Automobile Manufacturers Association (OICA), global automobile production in 2023 is 93.55 million units. (1) The widespread use of automobiles in [...]

Innovative and renewable polymers and additives are the focus of increased research due to public and environmental pressure. There has been a recent uptick in interest from scientists in biobased 'green' plasticizers that can be covalently bonded to replace harmful and migratory phthalate-based plasticizers. Vegetable oils (VOs) are one of the biosources, as they are both plentiful and sustainable. This review aims to highlight the synthesis methods for soy-based polyesters. Therefore, the chemistry of soybean oil as a polymeric material and its role in the synthesis of polyesters derived from soybeans are the primary topics of this review. This review covers the many ways in which soybean oil and its derivatives can be used to synthesize polyester, either directly or indirectly. Highlights * The need for sustainable polymers is explored. * Soybean oil-based polyesters are covered. * Modification and chemistry to convert soybean oil into polyester are described. * Applications of soybean-based polyesters are provided. KEYWORDS biopolymers, polyesters, soybean oil, sustainable polymers, synthesis, 1 I INTRODUCTION At the current pace of usage, fossil fuels will be used up by 2050. (1,2) This is why the use of bio-based feedstock is gaining popularity in [...]

The reversible bonding of microfluidic chips has been developing rapidly with the requirement of reusable microfluidic devices or the need to obtain the samples inside the chip. Traditional bonding methods for polymer-based microfluidics, e.g., thermal bonding, permanently attach the substrate and cover plate. Sometimes, once the chip flow channel is blocked, it is difficult to clean and affect the reusability of the chip. This study proposes a new reversible bonding method for poly (methyl methacrylate) (PMMA) microfluidic chips with the help of stretch release adhesive strips. The designed microchannels were fabricated on the surface of PMMA plates using C[O.sub.2] laser irradiation. Then, stretch release adhesive strips were used as an intermediate layer between the substrate (with microchannels) and another flat PMMA/PS/PC plate to seal the microchannel. The assembled chip sets were bonded at room temperature with bonding strength comparable with other permanent bonding methods. Experimental results show that simply pulling the adhesive layer by applying a shear force can easily detach the intermediate adhesive layer from both the substrate and cover plate to separate the bonded chipset. The proposed reversible bonding method is simple, rapid and has low residue and high bonding strength. Bacterial culture experiments were also conducted to verity the biocompatibility of the proposed bonding method. The proposed reversible bonding technique can be used for polymer-based microfluidic devices that require sample recovery or chip reuse. Highlights * The stretch release adhesive strip can provide high bond strength. * It allows easy peeling for reversible bonding. * It bonds at room temperature with simple operation. * It has good transparency for easy observation of experiments. * It has good biocompatibility. KEYWORDS microfluidics, reversible bonding, stretch release adhesive strip, 1 | INTRODUCTION Microfluidic technology is a technique that utilizes fluids at the micro- or nanometer scale for precise operations and control, with widespread applications in biology, chemistry, medicine, and [...]

Hot embossing is a low-cost and flexible method for fabricating microstructures and nanostructures on polymers. However, the conventional hot embossing process poses two challenges: First, the plates that are used do not provide uniform pressure, and the size of the chamber limits the imprinting area. Second, heating with thick metal plates significantly lengthens cycle time. Finally, the uniformity of temperature also affects the embossing results. To achieve a high heating rate and uniform pressure over a large area, this study combined an induction heating system and roll-to-plate hot embossing. A movable plate was used to move the mold through the induction coil, increasing the heating area and overcoming limitations related to the embossing area posed by the coil length. The imprinting area reached 100 * 100 [mm.sup.2]. In addition, the temperature difference was less than 20[degrees] C at each molding temperature range from 150[degrees] C to 190[degrees] C. The mold and the substrate were placed on a vacuum absorber to prevent deformation and slippage of the mold and provide preloading and packing pressure. Cooling fans were employed to improve cooling efficiency. Experimental replication yielded replication rates higher than 97% at 190[degrees] C and 5 kgf/[cm.sup.2] with a cycle time of approximately 2 minutes. To verify the feasibility of the process, V-groove microstructures were successfully fabricated using a movable induction heating roller embossing facility. Highlights * The feasibility of the moving induction heating roller embossing process. * A vacuum movable platform prevents deformation and slippage of the substrate. * Improve the temperature uniformity of the movable platform. KEYWORDS hot embossing, induction heating, large area, microstructures, roll-to-plate, 1 | INTRODUCTION Advances in technology, such as the introduction of semiconductors and fiber optic communications, have accelerated the trend toward miniaturization, densification, and high precision in the development of [...]

The demolding process in micro-injection molding constitutes a critical phase, exerting a decisive influence on the quality of polymer microstructures. In this study, the demolding forces of PMMA microfluidic chips were measured under different demolding temperatures, packing pressures, and demolding speeds by using pure nickel (Ni) mold insert. The dimensional deviations of the microchannels with different aspect ratios were analyzed. In addition, the effect of mold insert modification on the demolding force was further analyzed. The results showed that the effect of demolding temperature on the demolding force was the most significant, and the peak demolding force decreased with the decrease in temperature. The width of the microchannels increased and the depth decreased after demolding, while the opposite results were observed for the micro-mixing structures. However, the dimensional deviation of the micromixing structures was larger than that of the microchannels. Using the optimal molding parameters, the peak demolding force could be reduced from 114.0 N at 110[degrees]C to 47.0 N, a decrease of 58.8%. It is noteworthy that, when the microchannel was narrower than 100 [micro]m, achieving precise replication of microchannel dimensions became progressively more challenging as the microchannel width decreased. Using the Ni-W[S.sub.2] mold insert with low surface energy and low friction coefficient, the demolding force could be further reduced by 38.3%. The effect of the molding quality of microfluidic chip microstructures on the mixing performance of heavy metals was demonstrated by micro-mixing experiments. Highlights * Demolding temperature crucially affects microstructure dimensions. * Optimal parameters and modified mold insert reduce demolding force by 38.3%. * Dimensional deviation increases with the increase of microchannel aspect ratio. * Optimized microfluidic chip enhances [Co.sup.2+] chemiluminescence by 6.42%. KEYWORDS demolding force, dimensional deviation, microfluidic chip, micro-injection molding, microstructure, 1 | INTRODUCTION Microfluidics is extensively employed in various fields such as biotechnology, chemical analysis, and medical diagnosis. (1,2) Microfluidic chips, which integrate an array of microstructures including microchannels, microcolumns, [...]

Biopolymer blend nanocomposite films composed of polyvinyl alcohol (PVA) and chitosan (CS) with varying quantities of hydroxyapatite (HA) nanoparticles were developed using a green solution casting method. The formation of blend nanocomposite was confirmed by Fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible (UV) spectrometer, field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Mechanical parameters such as tensile strength, percentage elongation at break, hardness, dielectric constant, and temperature-dependent alternating current (AC) conductivity were analyzed. The bonding between the nanoparticles and PVA/CS blend was verified by the shift in distinctive peaks of blend in the nanocomposites to a higher wavenumber in the FTIR spectra. The UV spectra demonstrated the difference in absorbance and transmittance of the PVA/CS blend with the reinforcement of HA nanofillers. The bandgaps of the nanocomposites marginally decreased with an increase in nanoparticle loading. The SEM and XRD patterns revealed the ordered arrangement of the blend matrix due to the presence of nanoparticles. The assessment of thermal characteristics obtained from DSC and TGA demonstrated a clear increase in phase transition temperature and thermal stability of nanocomposites. The electrical conductivity measurement indicated a rise in dielectric constant and AC conductivity of blend nanocomposites with the addition of nanoparticles. The temperature-dependent AC conductivity showed a reduction in activation energy as temperature and nanoparticle loading increased. The tensile strength and surface hardness of the PVA/CS blend nanocomposite increased with the dosage of HA content in the blend matrix. Highlights * A series of polyvinyl alcohol (PVA)/chitosan (CS)/hydroxyapatite (HA) nanocomposites were prepared by the green method * Enhanced optical property, thermal stability, and glass transition temperature * Possess excellent dielectric constant and alternating current conductivity * The inclusion of HA increased the mechanical strength of the PVA/CS blend * A potential blend nanocomposite for flexible optoelectronic and charge storage devices. KEYWORDS AC conductivity, chitosan, crystallinity, dielectric constant, hydroxyapatite, polyvinyl alcohol, tensile strength, thermal properties, 1 | INTRODUCTION In recent years, many additional breakthroughs have been achieved to reduce environmental threats and crises. The development of economically and environmentally friendly polymers and their enhanced production [...]

Here, we report a photoclicked crystalline monomer DiPy which forms polymeric hydrogel Polym-DiPyC3. The monomer DiPy and polymer Polym-DiPyC3 are well characterized using spectroscopic and analytical techniques. The rheometric curve revealed the hydrogel Polym-DiPyC3 to exhibit viscoelasticity with a damping factor (tan[delta]) in the range between 0 and 1. The considered hydrogel film on exposure to mercury concentration [greater than or equal to] 2 ppm showed a loss of transparency and swellability. Energy dispersive x-ray and mapping confirmed the mercury presence on the surface of Polym-DiPyC3. The material behaves as a naked-eye indicator due to gain in opacity and loss of swellability. The DFT parameter supported the soft Lewis acid [Hg.sup.2+] to guest onto the soft thioether site of the polymer film Polym-DiPyC3. Highlights * The monomer DiPy was synthesized via thiol-alkene photoclick reaction. * The ionic polymer Polym-DiPyC3 is physically crosslinked. * The polymer Polym-DiPyC3 exhibits viscoelastic property. * The mercury presence causes Polym-DiPyC3 to lose its hydrogel property. * The observed affinity of mercury for sulfur was well supported with DFT. KEYWORDS DFT, hydrogel, mercury, thiol-alkene click reaction, viscoelasticity, 1 | INTRODUCTION Drinking water and life sustenance are interlinked. The drinking water availability with increased urbanization has decreased significantly. There is a need to overcome the mismanagement of bio-hazard [...]

This article provides the first multivariate analysis of reported thermal contact resistance (TCR) values from different characterization approaches (injection and compression molding) having missing data. The missing data are estimated by principal components analysis (PCA) with alternating least squares (ALS), and then the main effects are modeled using multiple regressions. Three models of increasing complexity are presented, each of which provides reasonable model fidelity relative to the TCR values reported in the literature. The primary cause of differences between reported TCR values as characterized by injection molding and compression molding can be explained by the melting of the polymer to make intimate contact with the metal mold during processing. Typical values of TCR are on the order of 0.0002 [m.sup.2]K/W, corresponding to heat transfer coefficients of 5000 W/([m.sup.2]K). The analyses suggest that the TCR decreases significantly with increasing processing temperature and pressure but increases most significantly during cooling with the development of an air gap between the polymer and mold. Accordingly, it is strongly recommended that injection molding simulations incorporate modeling of the TCR as a function of the processing states for accurate prediction of the air gap, residual stresses, shrinkage, and warpage. Highlights * Multivariate analysis of thermal contact resistance data from the literature. * Sparse data handled by principal component analysis and alternating least square. * Comparison of injection molding and compression molding measurements. * Results suggest thermal contact resistance should be modeled as a function of the processing states. KEYWORDS heat transfer, heat transfer coefficient, injection molding, interface, thermal contact resistance, 1 | INTRODUCTION Thermal contact resistance (TCR) in injection molding refers to the resistance to heat transfer at the interface between the hot polymer melt and the cold mold surface. [...]

Fiber-reinforced polymer composites (FRPCs) present a promising solution for diverting waste generated by the pulp and paper industry from landfills. The global pulp and paper industry generated 110 million tons [...]

The pilot-scale fluoropolymer incineration study conducted by the Karlsruhe Institute of Technology (KIT) represents a significant stride in understanding the environmental impact of fluoropolymer disposal. Fluoropolymers' End-of-Life Fluoropolymers, high-performance plastics [...]