Ethylene-propylene Copolymer Research Articles

Transformative and sustainable approach to waste plastic mixture valorization

The development of innovative methods for waste plastic valorization can benefit the environment and economy. In this study, the full spectrum of products (gas, oil, and solid products) resulting from the pyrolysis–reforming of a plastic mixture functioned as precursors of value-added products: 1) ethylene–propylene copolymers, 2) polyacrylonitrile (PAN)-based carbon nanofibers (CNFs), and 3) carbon quantum dots (CQDs). The CNFs were subsequently applied as supercapacitor electrodes, whereasthe CQDs acted as co-sensitizers for the primary sensitizer, N3, in dye-sensitized solar cells (DSSCs). Adding oil to PAN increased the specific capacitance of the CNFs by 46.12% to 226.64F/g, compared with that of pure PAN CNFs. With the aid of CQDs, the short-circuit current density and photo-conversion efficiency of DSSCs increased by 25.89% and 17.08%, respectively. Mechanisms associated with the integrated valorization pathway were proposed.

Enhanced Feedstock Processability for the Indirect Additive Manufacturing of Metals by Material Extrusion through Ethylene-Propylene Copolymer Modification.

Filament-based material extrusion (MEX) represents one of the most commonly used additive manufacturing techniques for polymer materials. In a special variation of this process, highly filled polymer filaments are used to create metal parts via a multi-step process. The challenges associated with creating a dense final part are versatile due to the different and partly contrary requirements of the individual processing steps. Especially for processing in MEX, the compound must show sufficiently low viscosity, which is often achieved by the addition of wax. However, wax addition also leads to a significant reduction in ductility. This can cause filaments to break, which leads to failure of the MEX process. Therefore, the present study investigates the influence of different ethylene-propylene copolymers (EPCs) with varying ethylene contents as a ductility-enhancing component within the feedstock to improve filament processing behavior. The resulting feedstock materials are evaluated regarding their mechanical, thermal and debinding behavior. In addition, the processability in MEX is assessed. This study shows that a rising ethylene content within the EPC leads to a higher ductility and an enhanced filament flexibility while also influencing the crystallization behavior of the feedstock. For the MEX process, an ethylene fraction of 12% within the EPC was found to be the optimum regarding processability for the highly filled filaments in MEX and the additional processing steps to create sintered metal parts.

Investigation on the oil permeation–adsorption–diffusion combined action mechanism of the adsorbed layer for flexible oil storage in waters

A novel method entitled flexible oil storage in waters is proposed, aiming to address the limitations of current oil storage systems and enhance the country's oil storage capacity. However, oil contamination severely restricts its applicability. To ensure the environmental sustainability of the method, the adsorbed layer is added outside the oil bladder, and the study investigates the material and the action mechanism of the adsorbed layer for flexible oil storage in waters. The results show that, with long breakthrough time and low oil concentration as criteria, the reed straw biochar is more suitable as the adsorbed layer filling material compared to the coconut shell and the apricot shell biochar and the fluorinated ethylene propylene copolymer is more suitable as the adsorbed layer membrane material compared to polyvinyl chloride. The adsorbed layer action mechanism involves multiple interactions, including permeation, adsorption, accumulation, and diffusion. They are coupled and together influence the adsorption effect. The empirical formula for the adsorbed layer's lifespan is derived, which helps in designing the adsorbed layer to satisfy specific lifespan requirements. This study provides theoretical and engineering guidance for the application of flexible oil storage in waters, contributing to the development of oil storage techniques.

Revealing the Molecular Interaction between CTL Base Oil and Additives and Its Application in the Development of Gasoline Engine Oil

In order to improve fuel economy to meet the standard for passenger car oil, a new formulation with good viscosity–temperature performance for gasoline engine oil is required. In this study, coal-to-liquid (CTL) base oil, with a high viscosity index and good low-temperature performance, was selected as the base oil to develop the gasoline engine oil. A systematic study on the molecular interaction between the CTL base oil and the viscosity index improver (VII), including three kinds of hydrogenated styrene diene copolymers (HSD-type) and four kinds of ethylene propylene copolymers (OCP-type), was conducted. It was found that in general, in CTL base oil, the HSD-type VII exhibited a much higher viscosity index, a significantly lower shear stability index, a higher thickening ability, and a lower cold-cranking simulator (CCS) viscosity than that of OCP-type VII. Moreover, when comparing CTL base oil with mineral oil 150N, the combination of CTL base oil and the VII displayed a lower CCS viscosity than that of mineral oil, suggesting it had better low-temperature performance and was able to quickly form a protective oil film on the surface, which was beneficial for the cold start. The functional group distribution state of the VII in base oil was analyzed using synchrotron radiation micro-infrared microscope (SR Micro-IR) technology, which revealed that HSD-1 had a better molecular interaction with CTL6 than 150N because of the better uniformity of the C=C group distribution. Based on this, a SP 0W-20 gasoline engine oil was developed by the combination of CTL base oil and the HSD-1 viscosity index improver, together with an additive package, a polymethacrylate pour point depressant, and a non-silicone defoamer, which showed excellent low-temperature performance, thermal oxidation stability, and detergency performance compared to the reference oil.

Effect of solvent type on chemical composition distribution analysis of polyolefins using crystallization elution fractionation (CEF)

For microstructure characterization of polyolefin by separation-based techniques with infrared detector, either 1,2-dichlorobenzene (o-DCB) or 1,2,4-trichlorobenzene (TCB) is commonly selected as a dissolution solvent and mobile phase. Herein, we studied the effects of o-DCB and TCB on the comonomer detection and chemical composition distribution (CCD) by crystallization elution fractionation (CEF) with a filter-based IR detector. We first compared the detector sensitivity on methyl group content or short chain branching (SCB) in polyethylene-co-butene with varied sample concentrations in o-DCB and TCB. TCB demonstrated superior comonomer detection in the IR detector with a single linear calibration across a wide range of sample concentrations. In contrast, o-DCB displayed stronger concentration dependent methyl group response, requiring a more complex equation in the calibration. Furthermore, o-DCB provided better separation of comonomer distribution with less peak broadening and co-crystallization effects, as observed with various polyolefins, including high density polyethylene (HDPE), linear low-density polyethylene (LLDPE), polypropylene (PP), and ethylene-propylene copolymer (EP).

Research on the Influence of Core Sensing Components on the Performance of Galvanic Dissolved Oxygen Sensors.

The galvanic dissolved oxygen sensor finds widespread applications in multiple critical fields due to its high precision and excellent stability. As its core sensing components, the oxygen-permeable membrane, electrode, and electrolyte significantly impact the sensor's performance. To systematically investigate the comprehensive effects of these core sensing components on the performance of galvanic dissolved oxygen sensors, this study selected six types of oxygen-permeable membranes made from two materials (Perfluoroalkoxy Polymer (PFA) and Fluorinated Ethylene Propylene Copolymer (FEP)) with three thicknesses (0.015 mm, 0.03 mm, and 0.05 mm). Additionally, five concentrations of KCl electrolyte were configured, and four different proportions of lead-tin alloy electrodes were chosen. Single-factor and crossover experiments were conducted using the OxyGuard dissolved oxygen sensor as the experimental platform. The experimental results indicate that under the same membrane thickness conditions, PFA membranes provide a higher output voltage compared to FEP membranes. Moreover, the oxygen permeability of FEP membranes is more significantly affected by temperature. Furthermore, the oxygen permeability of the membrane is inversely proportional to its thickness; the thinner the membrane, the better the oxygen permeability, resulting in a corresponding increase in sensor output voltage. When the membrane thickness is reduced from 0.05 mm to 0.015 mm, the sensor output voltage for PFA and FEP membranes increases by 86% and 74.91%, respectively. However, this study also observed that excessively thin membranes might compromise measurement accuracy. In a saturated, dissolved oxygen environment, the sensor output voltage corresponding to the six oxygen-permeable membranes used in the experiment exhibits a highly linear inverse relationship with temperature (correlation coefficient ≥ 98%). Meanwhile, the lead-tin ratio of the electrode and electrolyte concentration have a relatively minor impact on the sensor output voltage, demonstrating good stability at different temperatures (coefficient of variation ≤ 0.78%). In terms of response time, it is directly proportional to the thickness of the oxygen-permeable membrane, especially for PFA membranes. When the thickness increases from 0.015 mm to 0.05 mm, the response time extends by up to 2033.33%. In contrast, the electrode material and electrolyte concentration have a less significant effect on response time. To further validate the practical value of the experimental results, the best-performing combination of core sensing components from the experiments was selected to construct a new dissolved oxygen sensor. A performance comparison test was conducted between this new sensor and the OxyGuard dissolved oxygen sensor. The results showed that both sensors had the same response time (49 s). However, in an anaerobic environment, the OxyGuard sensor demonstrated slightly higher accuracy by 2.44%. This study not only provides a deep analysis of the combined effects of oxygen-permeable membranes, electrodes, and electrolytes on the performance of galvanic dissolved oxygen sensors but also offers scientific evidence and practical guidance for optimizing sensor design.

Microplastics in personal care products and cosmetics in Sri Lanka

In the Sri Lankan context, the lack of baseline studies to mitigate microplastic emissions through personal care and cosmetic products poses a huge problem. Hence this study serves as the first scientific investigation to analyze and characterize microplastics in selected personal care and cosmetic items available in the Sri Lankan markets. Fifteen brands representing five categories (face wash, facial scrubs, baby creams, shaving creams, and skin creams) of personal care and cosmetic items served as the basis for this investigation. Based on a questionnaire survey, from each category, three highly utilized brands were chosen and triplicates from each brand were used for the analysis. All samples were treated with the Fenton reagent to extract microplastics. Then through Nile red staining suspected microplastic were screened and characterized through FT-IR spectroscopy. The Nile Red analysis revealed seven brands of the fifteen to be stained with Nile Red and demonstrate luminance properties under UV light. However, FT-IR analysis proved only six brands contained actual microplastics. Low-density polyethylene and ethylene-propylene copolymer were the dominant types of microplastic. Most microplastics were irregularly shaped and white in color with sizes ranging from 238.55 ± 50.74 to 450.69 ± 174.9 μm. An emission estimation revealed that products FS-01 and FW-03 contain 3.36 ± 0.20 g and 0.2 ± 0.05 g of isolatable microplastics per product. While the present study provides scientific evidence for the availability of microplastics in products in Sri Lankan markets, it also provides a great opportunity to develop relevant policies and regulations to control them.

A glass-assisting thermally stimulated discharge technique

Thermally stimulated discharge (TSD) technique is a traditional method in dielectric research, especially for electrets. However, in conventional open-circuit and short-circuit TSD techniques, it is difficult to distinguish the surface charge and body charge of dielectric materials. In particular with the test of polymer electrets, the deformation of the polymer film may take place during the measurement process, which will affect the accuracy of the experiment results. In this paper, a glass-assisting TSD (GA-TSD) technique is proposed to solve the above problems. The feasibility of the experimental technique is verified with the GA-TSD spectra of fluorinated ethylene-propylene copolymer electret films. In addition, their theory analysis is also accomplished. The influences of glass thickness, glass dielectric property, and metallizing on the glass on GA-TSD spectra are investigated. The results prove that the GA-TSD spectra can clearly distinguish the difference between surface charge and body charge according to the current direction. The quartz glass with the lowest dielectric constant is best suitable for the GA-TSD technique. The influence of the glass thickness and metallizing on the glass on GA-TSD spectra is little.

Disposable surgical/medical face masks and filtering face pieces: Source of microplastics and chemical additives in the environment

The production and consumption of disposable face masks (DFMs) increased intensely during the COVID-19 pandemic, leading to a high amount of them being found in the terrestrial and aquatic environment. The main goal of this research study is to conduct a comparative evaluation of the water-leachability of microplastics (MPs) and chemical additives from various types of disposable surgical/medical face masks (MM DFMs) and filtering face pieces (FFPs). Fourier-Transform Infrared Spectroscopy was used for MPs analysis. Liquid Chromatography/High Resolution Mass Spectrometry was used to analyse analytes presented in the water-leachates of DFMs. FFPs released 3–4 times more microplastic particles compared to MM DFMs. The release of MPs into water from all tested DFMs without mechanical stress suggests potential MP contamination originating from the DFM production process. Our study for the first time identified bisphenol B (0.25–0.42 μg/L) and 1,4-bis(2-ethylhexyl) sulfosuccinate (163.9–115.0 μg/L) as leachables from MM DFMs. MPs in the water-leachates vary in size, with predominant particles <100 μm, and the release order from DFMs is MMIIR > MMII > FFP3>FFP2>MMI. The main type of microplastics identified in the water leachates of the investigated face masks was polypropylene, accounting for 93–97% for MM DFMs and 82–83% for FFPs. Other polymers such as polyethylene, polycarbonate, polyester/polyethylene terephthalate, polyamide/Nylon, polyvinylchloride, and ethylene-propylene copolymer were also identified, but in smaller amounts. FFPs released a wider variety and a higher percentage (17–18%) of other polymers compared to MM DFMs (3–7%). Fragments and fibres were identified in all water-leachate samples, and fragments, particularly debris of polypropylene fibres, were the most common MP morphotype. The findings in this study are important in contributing additional data to develop science-based policy recommendations on the health and environmental impacts of MPs and associated chemical additives originated from DFMs.

Microstructure, Viscoelasticity, and Extensional Rheology of Ethylene–Propylene Copolymer Vitrimers

Microstructure, Viscoelasticity, and Extensional Rheology of Ethylene–Propylene Copolymer Vitrimers

Morphology of impact polypropylene copolymer extruded cast film revealed by confocal Raman imaging.

An impact polypropylene copolymer (IPC), composed of polypropylene (PP) and ethylene-propylene copolymer (EPC), was synthesized through two-stage in-reactor polymerization. A systematic investigation of the crystalline structure, thermal behavior, morphology, and tensile properties of the IPC extruded cast film was conducted. Specifically, the morphology of EPC was obtained by confocal Raman imaging by depicting the spatial distribution of the Raman band located at 1064 cm-1. The EPC phase exhibits fibrous morphology with the long axis aligning along the machine direction (MD). A three-dimensional (3D) heterogeneous structure of the IPC cast film obtained by confocal Raman imaging confirms that the fibrous EPC phase is dispersed in a 3D framework of the PP matrix. The mesomorphic phase in the as-prepared cast film transforms to a stable α-form crystal after annealing at 130 °C, which improves the yield strength but decreases the elongation of the cast film. The WAXD and SAXS results indicate that there is no obvious orientation of the crystallites. Thus, the anisotropy of tensile properties in the MD and transverse directions is closely related to the anisotropic phase morphology at the micrometer scale. The results reveal that the mechanical performances of IPC films are determined by the crystalline structure of the PP matrix and the morphology.

РОЛЬ ТЕХНОЛОГИЧЕСКИХ ФАКТОРОВ В ФОРМИРОВАНИИ СТРУКТУРЫ ОТКРЫТОПОРИСТЫХ ВСПЕНЕННЫХ МАТЕРИАЛОВ НА ОСНОВЕ ЭТИЛЕН-ПРОПИЛЕН-ДИЕНОВЫХ СОПОЛИМЕРОВ ПУТЕМ КОМПРЕССИОННОГО ФОРМОВАНИЯ

Ethylene-propylene copolymers (EPDM) are known for a wide range of useful properties. EPDM-based rubbers have weather resistance, resistance to aggressive environments and wide operating temperatures. EPDM-based blends allow to create composite materials such as open-cell polymer foam. Due to their unique composition, open-cell elastomeric foam based on EPDM can have different structures, densities and properties. This paper presents a study of the possibilities of technologies of first-stage and second-stage foaming in vulcanization presses in order to regulate the pore structure of open-cell material based on ethylene-propylene-diene copolymer.

Microplastics in the Water of Batang Anai Estuary, Padang Pariaman Regency, Indonesia: Assessing Effects on Riverine Plastic Load in the Marine Environment

Microplastic (MP) is one of the most dangerous contaminants due to its ecotoxicological impact on the aquatic environment, aquatic biota, and human health. Defined as particles less than 5 mm, these contaminants originates from either primary or secondary source. Therefore, this study aimed to analyze the abundance, shape, color, size, and type of microplastic (MP) polymers. In the process, water samples were collected from 3 distinct points in the Batang Anai River, to obtain MP. Subsequently, analysis was conducted using a microscope and Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR). The results showed that the abundance of MP in the water samples ranged from 37-77 particles/L, and the most dominant shapes, colors, and sizes identified were fragments (49.44%), black (48%), and sizes &gt;1,000 µm (33%), respectively. Characterization and interpretation of functional groups in the FTIR spectrum indicated the presence of cellulose polymer, ethylene-propylene copolymer, neoprene, and polyester. In conclusion, this report can be used as initial information to help control plastic waste pollution.

Study of the properties of compositions based on mixtures of butadiene-styrene rubber with mechanically modified ternary ethylene-propylene copolymer

Study of the properties of compositions based on mixtures of butadiene-styrene rubber with mechanically modified ternary ethylene-propylene copolymer

Room-temperature endogenous lubricant-infused slippery surfaces by evaporation induced phase separation.

We present a novel approach to fabricate endogenous slippery lubricant-infused porous surfaces (eSLIPS) at room temperature using an evaporation-induced phase separation process. The ternary coating system, comprising ethylene-propylene copolymer, caprylyl methicone, and n-hexane, forms a porous structure in situ infiltrated with lubricant, resulting in surfaces with remarkable anti-fouling and anti-icing properties.

Influence of Organoclay Content on Morphology and Properties of Poly(Lactic Acid)/Propylene-Ethylene Copolymer/Organoclay Composites

The effects of clay surface modified with 25-30 wt% of methyl dihydroxyethyl hydrogenated tallow ammonium (Clay-DHA) on morphology, mechanical and thermal properties of poly(lactic acid) (PLA)/propylene-ethylene copolymer (PEC)/Clay-DHA composites were investigated. The phase morphology of PLA/PEC blends showed phase separation due to weak interaction between PLA and PEC phase, and the droplet size of PEC phase increased with increasing PEC content. The addition of Clay-DHA significantly improved the compatibility between PLA and PEC phases due to PEC droplet size decreased dominantly in PLA matrix, so Clay-DHA could act as an effective compatibilizer. The tensile properties found that Young’s modulus of PLA/PEC blends decreased with increasing amount PEC while the strain at break increased. The incorporation of Clay-DHA improved Young’s modulus of the blends in a range of 10-20 wt% of PEC. The thermal properties showed that the addition of PEC and Clay-DHA had no effect on the melting temperature of PLA. The degradation temperature of PLA/PEC blends was higher than that of the PLA, so PEC could improve the thermal stability of the blends.

Two-Stage Method for the Synthesis of Reactor Heterophase Thermoplastic Elastomers Based on Polypropylene

A simple method for the two-stage synthesis in one reactor on one catalyst of heterophase thermoplasticelastomers based on isotactic polypropylene (PP) and an ethylene-propylene copolymer or an ethylene-propylene-1,4-hexadiene terpolymer is developed. The obtained materials, depending on the composition,have good elastomeric properties or behave like thermoplastics. Polymers in which ethylene units formlong sequences have the best set of basic characteristics: high values of the elastic modulus, strength, andelongation at a break, as well as a low residual deformation.

Synthesis and dynamic crosslinking of a hydroxyl-functionalized ethylene-propylene copolymer: Preparation of an elastomer with reprocessability and shape memory properties

The ternary copolymers of ethylene, propylene and 10-undecen-1-ol were prepared using a vanadium catalyst bearing an 8-anilide-5,6,7-trihydroquinoline ligand. By adjusting the concentration of 10-undecen-1-ol and polymerization temperature, the insertion rate of polar monomers was modulated with a maximum value of 3.8% achieved for 10-undecen-1-ol. With an increase in the hydroxyl insertion rate, the water contact angle of hydroxyfunctionalized ethylene-propylene copolymers decreased from 112.3° to 95.3°, indicating that the incorporation of 10-undecen-1-ol enhanced the hydrophilicity of the copolymers. Subsequently, a reprocessable ethylene-propylene rubber (EPR) with double dynamic bonds was synthesized through reaction between the hydroxyl group on functionalized ethylene-propylene copolymer and the crosslinking agent using isocyanate as chain end. The strength of functionalized ethylene-propylene copolymers was significantly improved through dynamic crosslinking. Significantly, the tensile strength of sample EP6-V-0.5 reached 14 MPa, which was 27 times higher than that of un-crosslinked EP6. The prepared functionalized ethylene-propylene rubber prepared exhibited not only reprocessability, but also remarkable shape memory and reshaping properties. Moreover, the conductive composite materials based on this rubber displayed great potential for application in motion sensors.

Ti(IV) Complexes with OSSO-Type Diol Ligands as Catalysts for Synthesis of Ultrahigh-Molecular-Weight Polyethylene and Ethylene–Propylene Copolymers

Ti(IV) Complexes with OSSO-Type Diol Ligands as Catalysts for Synthesis of Ultrahigh-Molecular-Weight Polyethylene and Ethylene–Propylene Copolymers

Thermally-triggered multi-shape-memory behavior of binary blends of cross-linked EPDM with various thermoplastic polyethylenes and their potential applications as temperature indicators

Shape-memory polymers (SMPs) are smart materials that can alter their configuration in response to external stimuli. They have shown promise in a number of application areas, including soft robotics or biomedical devices. Frequently, however, the materials needed are expensive, or labor-intensive synthetic processes are involved. In this contribution, we report a versatile and cost-effective manufacturing method for SMPs based on binary elastomer-thermoplastic-blends. These were produced from ethylene-propylene-diene monomer rubber (EPDM) combined with ultra-low-density polyethylene (ULDPE), propylene-ethylene copolymer (PP-c-PE), or high-density polyethylene (HDPE) as thermoplastic components. Atomic force microscopy revealed an immiscible two-phase morphology. Results of dynamic-mechanical thermal analysis showed that all polymer blends with a high thermoplastic load had efficient thermo-responsive dual-shape-memory, also demonstrated on macroscopic specimens. Furthermore, multi-shape-memory of elastomer/thermoplastic (40/60)-blends was investigated. Especially ULDPE-containing blends exhibited particularly promising multi-shape-memory features and stepless, controllable temperature response. Mechanistically, this is based upon the synergistic interaction of the cross-linked elastomer and the thermoplastic switching phase, consisting of different crystalline segments melting over a wide range from 60 to 125 °C. The continuous shape recovery over a broad temperature range could be used to create reusable test strips, e.g., for indicating exposure temperature in transportation chains or overheating protection.