Polymer Polyethylene Research Articles

Tensile and Microscopic Properties of High-Density Polyethylene Geonet for Rainwater Scour Resistance

In order to study the tensile properties of a high-density polyethylene (HDPE) geonet for rainwater scour resistance and the micro properties of HDPE after tensile failure, a series of tensile tests on the HDPE geonet were carried out by the material testing system (MTS) tensile device. In this study, a correlation has been proposed to analyze the relationship between elongation and tensile strength of geonet material. The microscopic characteristics of the HDPE geonet were observed by using a scanning electron microscope SU8000. The high-density polyethylene geonet for rainwater scour resistance was evaluated based on mechanical performance and microstructure. The rainwater scour resistance properties of the high-density polyethylene geonet were estimated. It is determined that the geonet improved the rainwater scour resistance of the soil slope. The mechanical test results indicated that the longitudinal mechanical properties of the geonet are better than the transversal. The scanning electron microscope images of the geonet results confirmed that the polyethylene polymer produces fine and neat radial cracks during the tensile process of the geonet. The findings of this work are essential for the fundamental understanding, design, and application of the geonet.

Radiative Cooling Nanofabric for Personal Thermal Management.

A wearable textile that is engineered to reflect incoming sunlight and allow the transmission of mid-infrared radiation simultaneously would have a great impact on the human body's thermal regulation in an outdoor environment. However, developing such a textile is a tough challenge. Using nanoparticle-doped polymer (zinc oxide and polyethylene) materials and electrospinning technology, we have developed a nanofabric with the desired optical properties and good applicability. The nanofabric offers a cool fibrous structure with outstanding solar reflectivity (91%) and mid-infrared transmissivity (81%). In an outdoor field test under exposure of direct sunlight, the nanofabric was demonstrated to reduce the simulated skin temperature by 9 °C when compared to skin covered by a cotton textile. A heat-transfer model is also established to numerically assess the cooling performance of the nanofabric as a function of various climate factors, including solar intensity, ambient air temperature, atmospheric emission, wind speed, and parasitic heat loss rate. The results indicate that the nanofabric can completely release the human body from unwanted heat stress in most conditions, providing an additional cooling effect as well as demonstrating worldwide feasibility. Even in some extreme conditions, the nanofabric can also reduce the human body's cooling demand compared with traditional cotton textile, proving this material as a feasible solution for better thermoregulation of the human body. The facile fabrication of such textiles paves the way for the mass adoption of energy-free personal cooling technology in daily life, which meets the growing demand for healthcare, climate change, and sustainability.

Mechanical and morphological properties of poly(vinyl chloride) and linear low‐density polyethylene polymer blends

AbstractIn this article, nonpolar polyethylene with polar poly(vinyl chloride) is considered as a polymer–polymer mixture. Direct mixing of poly(vinyl chloride) and polyolefins leads to the formation of incompatible mixtures that have weak complex properties. To form this mixture, chlorinated polyethylene and a copolymer of polyvinyl chloride with polyethylene were used as compatibilizers. An extreme relationship of the elastic modulus on the composition of the blend at a PE content (5–20 wt.%) was revealed. The use of EBM model representations made it possible to identify the reasons for this relationship, namely, the cumulative contribution of structural changes in PVC and the enhancement of interfacial adhesion due to the presence of a compatibilizer at the phase boundary.

Atmospheric Plasma‐Assisted Deposition and Patterning of Natural Polymers

AbstractPlasma‐assisted deposition is a facile, yet sophisticated method to form biocompatible coatings on materials and introduce specific surface interactions. The plasma process provides unique features such as surface activation, functionalization, and assisted polymerization, all of which can be obtained under low power and room temperature conditions. Plasma‐assisted deposition can further provide coatings with enhanced adhesion and stability. Here, it is reported for the first time, a method for the controlled plasma deposition of the versatile biomaterial chitosan on a range of substrates – soda‐lime glass, metal alloy (Ti4Al6V), thermoplastic polymer (polyethylene terephthalate), and silicone rubber (poly(dimethylsiloxane)). The deposited chitosan films are characterized by atomic force microscopy, scanning electron microscopy and Fourier transform infrared spectroscopy, and evaluated for adhesion and stability. The proposed method is also successfully optimized for the deposition of multiple layers of different biomaterials. Specifically, coatings comprising alternate chitosan and silk fibroin layers are realized, together with patterned surfaces with programmable surface composition. The biological response of the chitosan‐on‐fibroin and fibroin‐on‐chitosan surfaces with and without patterning are investigated using cell culture experiments. Selective area deposition enables the development of improved surface finishes for biomedical devices.

Thermal, structural and morphological properties of polypropylene and high density polyethylene polymer composites filled with waste urea formaldehyde

Thermal, structural and morphological properties of polypropylene and high density polyethylene polymer composites filled with waste urea formaldehyde

Developing future visions for bio-plastics substituting PET – A backcasting approach

The demand for plastics far exceeds that for any other bulk material and is expected to grow further due to global economic and population growth. Packaging is by far the largest end-user segment for plastics. Interest in bioplastics is increasing as public awareness of plastic waste accumulation in natural environments increases. 2,5-Furandicarboxylic acid (FDCA) is the key monomer in the production of polyethylene 2,5-furandicarboxylate (PEF), a polymer that offers a sustainable solution to replace the commonly used polymer polyethylene terephthalate (PET). A backcasting workshop with 42 experts was held to identify current barriers and challenges that block the commercialization of FDCA-based products and to outline potential pathways toward future market diffusion. Several barriers which are strongly related to technological and market-related aspects are preventing the full potential of FDCA from being unlocked. FDCA products cited in the literature are versatile and cover a wide array of niche applications. In the backcasting workshop, participants described their specific – yet highly divergent – future visions for PEF. Participants with a background in FDCA production referred mostly to developments that would need to take place in the field of FDCA applications to turn their vision into reality, while participants with a background in FDCA product development tended to refer to open issues related to FDCA synthesis. The findings of this study indicate that there is a great need for intensified cross-disciplinary communication and collaboration.

Investigation of two different size microplastic degradation ability of thermophilic bacteria using polyethylene polymers

There are several studies stating that many types of microplastics cannot be retained completely by conventional wastewater treatment systems. Therefore, it is necessary to prevent discharge of these microplastics to the ecological system. The objective of this study was to investigate the biodegradation ability of two different size of PE (50 and 150 µm) by using two Gram-positive, spore-forming, rod-shaped, and motile thermophilic bacteria, called strain Gecek4 and strain ST5, which can hydrolyze starch, were isolated from the soil’s samples of Gecek and Ömer hot-springs in Afyonkarahisar, Turkey, respectively. Phenotypic features and 16S rRNA analyzing of strains also studied. According to these results, Gecek4s and ST5 identified as Anoxybacillus flavithermus Gecek4s and Bacillus firmus ST5, respectively. Results showed that A. flavithermus Gecek4s can colonize the polymer surface and cause surface damage whereas B. firmus ST5 could not degrade bigger-sized particles efficiently. Moreover, morphological changes on microplastic surface were investigated by scanning electron microscopy (SEM) where dimensional changes, irregularities, crack, and/or holes were detected. This finding suggests that there is a high potential to develop an effective integrated method for plastic bags degradation by extracellular enzymes from bacteria.

Orientation analysis of polymer thin films on metal surfaces via IR absorbance of the relative transition dipole moments

Modern technology has increasing requirements for thin film based electronic devices. Many surface and electronic properties strongly depend on the orientation of the material. Industrial development has a need for cheap, non-destructive, and fast orientation analysis in different conditions. Infrared-orientation analysis is less represented in literature compared to other orientation methods, while offering a lot of unique advantages. In this respect for thin polymeric films, we propose infrared (IR) absorbance-spectroscopy near metal surfaces to distinguish the orientation of different molecular segments. By use of the ratio method, the calculation of the orientation becomes mostly independent from the angle of incidence and averages out aperture errors of the measurement setup, hence the given solutions are generally applicable for many setups. For the most common point groups, the hereby-presented mathematical solution is valid for thin films cast on metal surfaces. Extensive quantum mechanical calculations of the transition dipole moments are avoided for known IR spectroscopy bands. The detailed application of the given IR orientation analysis is demonstrated for the polymers polystyrene, polyethylene glycol, poly(methyl methacrylate) and polyvinyl acetate. Each segment of these polymers is analyzed for the preferred molecular orientation in respect to the surface.

Spatial and temporal variations of microplastic concentrations in Portland's freshwater ecosystems

While microplastics are a pollutant of growing concern in various environmental compartments, less is known regarding the sources and delivery pathways of microplastics in urban rivers. We investigated the relationship between microplastic concentrations and various spatiotemporal factors (e.g., land use, arterial road length, water velocity, precipitation) in two watersheds along an urban-rural gradient in the Portland metropolitan area. Samples were collected in August, September, and February and were analyzed for total microplastic count and type. Nonparametric statistics were used to evaluate potential relationships with the explanatory variables, derived at both the subwatershed and near stream scales. In August, microplastic concentrations were significantly higher than in February. August concentrations also negatively correlated with flow rate, suggesting that lower flow rates may have facilitated the accumulation of microplastics. Smaller size microplastic particles (< 100 μm) were found more in August than September and February, while larger size particles were more dominant in February than the other months. Microplastic concentrations were positively related to 24-h antecedent precipitation in February. Negative correlations existed between wet season microplastic concentrations and agricultural lands at the near stream level. The results indicate that near stream variables may more strongly influence the presence and abundance of microplastics in Portland's waterways than subwatershed-scale variables. Fragments were the most commonly observed microplastic morphology, with a dominance of gray particles and the polymer polyethylene. The findings of this study can inform management decisions regarding microplastic waste and identify hotspots of microplastic pollution that may benefit from remediation.

Effect of plastic pollution in soil properties and growth of grass species in semi-arid regions: a laboratory experiment.

Since the year 2020, the use of plastic as a strategy to mitigate the spread of COVID-19 disease has been given substantial attention. Global environmental contamination of plastic creates waste and is a known threat to soil ecosystems as a main sink of microplastics. However, there is still considerable uncertainty about microplastics controlling soil properties alteration. Therefore, we carried out an incubation experiment with soil and Carex stenophylla Wahlenb., which are the dominant soil and grass species in semi-arid regions. We investigated the effect of polymer polyethylene terephthalate (PET) concentrations (0%, 1%, 3%, and 5%) on C. stenophylla growth and soil ammonium-N and nitrate–N, organic matter content, pH, soil aggregates, and soil respiration. When soils were exposed to PET microplastics, fewer seeds germinated (62.8 ± 32%) but not significantly (p value > 0.05) when soils were treated to 0, 1, 3, and 0.5% PET. Shoot height was also not effectively reduced with PET. The soil pH was considerably lower when exposed to higher PET compared to all other treatments with the soil exposed to 5% w/w PET for both unplanted and planted, being 0.84 and 0.54 units, respectively, lower than the controls. The soil microbial respiration under exposure to PET was considerably increased in comparison to control samples. Moreover, the presence of PET resulted in potential alterations of soil stability, and with PET present soil stability increased. In conclusion, PET microplastics cannot significantly affect the development of C. stenophylla but could affect crucial soil properties. In addition, changes occurred with increased variability in soil ammonium-N and nitrate–N, particularly at a high PET ratio.

Plastic waste recycling: existing Indian scenario and future opportunities.

This review article aims to suggest recycling technological options in India and illustrates plastic recycling clusters and reprocessing infrastructure for plastic waste (PW) recycling in India. The study shows that a majority of states in India are engaged in recycling, road construction, and co-processing in cement kilns while reprocessing capabilities among the reprocessors are highest for polypropylene (PP) and polyethylene (PE) polymer materials. This review suggests that there are key opportunities for mechanical recycling, chemical recycling, waste-to-energy approaches, and bio-based polymers as an alternative to deliver impact to India’s PW problem. On the other hand, overall, polyurethane, nylon, and polyethylene terephthalate appear most competitive for chemical recycling. Compared to conventional fossil fuel energy sources, polyethylene (PE), polypropylene (PP), and polystyrene are the three main polymers with higher calorific values suitable for energy production. Also, multi-sensor-based artificial intelligence and blockchain technology and digitization for PW recycling can prove to be the future for India in the waste flow chain and its management. Overall, for a circular plastic economy in India, there is a necessity for a technology-enabled accountable quality-assured collaborative supply chain of virgin and recycled material.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13762-022-04079-x.

The addition of GO-SiO2 to synthesis polyethylene terephthalate composite with enhanced crystalline and mechanical properties

The graphene oxide-silica, GO-SiO2 (GS) nanoparticles synthesized by in-situ hydrolysis were grafted with block polymers polyethylene glycol (PEG) and low-molecular polyethylene terephthalate (LPET) using 3-isocyanatopropyltrimethicone (IPTES) as a bridge to prepare the additive GS-IPTES plus PEG-LPET (GSIP). This grafting process was confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The GSIP of various contents was used as reinforcing fillers to prepare PET/GSIP composite by melt blending. The crystallization and mechanical properties of the PET/GSIP composite were dramatically enhanced with the addition of small amounts of GSIP. Compared with pure PET, the crystallization temperature of PET/GSIP was increased by 41 °C at 1 wt.% addition of GSIP. Moreover, the highest tensile strength was 91.2 MPa and the highest modulus was 14.7 GPa at 0.8 wt.% addition. The crystalline and mechanical properties improvements were attributed to the synergistic effects of GS and block polymer chains.

Practical experience with modified bitumen and bituminous binders

To date, the issue of polymer waste recycling becomes relevant, because every year the amount of plastic and polyethylene waste increases, which leads to devastating effects on flora and fauna everywhere. One of the ways to solve this problem of polymer waste recycling is to use them to modify asphalt-concrete mixture and bitumen. Thus, two problems are solved at once: reuse of plastic, polyethylene, and other polymer wastes and improvement of asphalt concrete pavement with an increase in its service life. The paper presents a discussion of the use of modified bitumen in the construction of highways and roads, the design and technological solutions, features of the technology of modified bitumen, as well as the results of laboratory tests of modified bitumen, based on which was decided on the advisability of using. The use of the combined approach of the road pavement allows increasing the service life of the road.

Cotton noil based cellulose microfibers reinforced polylactic acid composite films for improved water vapor and ultraviolet light barrier properties

AbstractThe cellulose reinforced polylactic acid (PLA) composites are one of the most widely explored biopolymer composites in packaging applications. In this study, the cellulose microfibers (CMF) isolated from cotton noil were reinforced with 1%, 3%, 5%, 10%, and 20% in PLA matrix by solvent casting method. The strong interfacial adhesion and enhanced dispersion of CMF in PLA polymer matrix increased the tensile, water vapor, ultraviolet (UV) light barrier properties of the composites. The ultimate tensile stress and Young's modulus of 1% CMF reinforced composites were increased by 46% and 30% respectively than that of control films. A further increase in percent CMF reinforcement of up to 20% slightly reduced the tensile strength of composites but was comparable to that of low‐density polyethylene polymer. The water vapor permeability was decreased while increasing the CMF reinforcement due to the increased diffusion path by the dispersed CMF. The UV light absorbance of the composite was improved by up to 90% with the increase in CMF reinforcement by up to 20% due to the increased chromophore groups of cellulose. Hence, the PLA‐CMF composites could be used for packaging and storing light and moisture‐sensitive products.

Phototherapy Using a Fluoroquinolone Antibiotic Drug to Suppress Tumor Migration and Proliferation and to Enhance Apoptosis.

In this work, a fluoroquinolone antibiotic drug (sparfloxacin (SP)) was selected as a chemotherapy drug and photosensitizer for combined therapy. A facile chemical process was developed to incorporate SP and upconversion nanoparticles (UCNPs) into the thermally sensitive amphiphilic polymer polyethylene glycol-poly(2-hexoxy-2-oxo-1,3,2-dioxaphospholane). In vitro and in vivo experiments showed that 60% of the SP molecules can be released from the micelles of thermal-sensitive polymers using a 1 W cm-2 980 nm laser, and this successfully inhibits cell migration and metastasis by inhibiting type II topoisomerases in nuclei. Additionally, intracellular metal ions were chelated by SP to induce cancer cell apoptosis by decreasing the activity of superoxide dismutase and catalase. In particular, the fluoroquinolone molecules produced singlet oxygen (1O2) to kill cancer cells, and this was triggered by UCNPs when irradiation was performed with a 980 nm laser. Overall, SP retained a weak chemotherapeutic effect, achieved enhanced photosensitizer-like effects, and was able to repurpose old drugs to elevate the therapeutic efficacy against cancer, increase the specificity for suppressing tumor migration and proliferation, and enhance apoptosis.

Ionic liquid doped solid polymer electrolyte: Synthesis, characterization and applications ICSEM-2021

In this paper, we have used polymer polyethylene oxide as a host matrix and novel electrolyte ionic liquid 1-ethyl-3-methylimidazolium tricyanomethanide as an dopant to increase ionic mobility. Different characterization techniques like Electrochemical impedance spectroscopy, dielectric measurement, Fourier transform, X-ray diffraction, polarized optical microscopy, thermogravinometric analysis were used to identify the electrical, optical, structural and thermal properties. A laboratory scale supercapacitor has been fabricated using optimized solid polymer electrolyte film as an electrolyte and porous carbon derived from corn starch which shows a specific capacitance 13.6 F/g at 50 mV/s scan rate.

Reduction of CT Artifacts Using Polyetheretherketone (PEEK), Polyetherketoneketone (PEKK), Polyphenylsulfone (PPSU), and Polyethylene (PE) Reconstruction Plates in Oral Oncology

Surgical reconstruction after segmental mandibulectomy in patients with oral cancer commonly requires implantation of titanium plates, which cause metallic artifacts in CT examinations detrimental for image quality. Therefore, the aim of the present study was to evaluate CT artifacts and image quality of the polymer plate materials polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyphenylsulfone (PPSU), and polyethylene (PE) in mandible reconstruction. Five plates (titanium, PEEK, PEKK, PPSU, and PE) were successively surgically inserted in a human cadaveric specimen using eight (1) titanium and (2) zirconium oxide screws. Streak and blooming artifacts were assessed in 1mm CT scans with and without metallic artifact reduction algorithms (MAR) in this cross-sectional study. The different plate materials were analyzed for their effect on Hounsfield unit (HU) values resulting in streak artifacts. Blooming artifacts were measured as virtual growth of plates compared to actual size. Subjective image quality was assessed by 3 independent observers. Statistics were conducted by multifactorial ANOVA and Bonferroni's post hoc test. Titanium (182.42 HU; SD±3.09) was associated with significantly more streak and blooming artifacts compared to the polymers PEEK (86.41 HU; SD±1.72; P<.001), PEKK (85.50 HU; SD±2.75; P<.001), PPSU (85.51 HU; SD±1.97; P<.001), and PE (85.52 HU; SD±3.33; P<.001) implants. No significant differences could be seen between the screw types (titanium vs zirconium oxide) (P=.75) or the activation or inactivation of MAR (P=.85). Image quality was best for PE and worst for titanium implants in combination with zirconium oxide screws. Polymers plate materials PEEK, PEKK, PPSU, and PE significantly reduce CT artifacts and improve image quality facilitating the radiological interpretation of implant surrounding tissues. This effect is beneficial for radiological tumor follow-up and CT-based planning of adjuvant radiotherapy.

Mechanical scission of a flexible polymer (polyethylene oxide) under highly turbulent flows through abrupt contractions

We analyze the polymer scission of a flexible polymer (polyethylene oxide) in a turbulent flow in pipelines, including abrupt contractions. The role played by these local occurrences is studied for an extensive range of concentrations and molecular weight over time (passes through our system). We pointed that the final value of the drag reduction parameter (DR) is independent of the initial value of molecular weight. This behavior is different for flows in straight tubes in the absence of local occurrences. We propose a model for DR as a function of concentration, molecular weight, contraction rate, and the number of passes through the system. We also showed that the fall of DR is linearly dependent on the molecular weight decrease.

Microplastics in marine and aquatic habitats: sources, impact, and sustainable remediation approaches.

Plastic trash dumped into water bodies degrade over time into small fragments. These plastic fragments, which come under the category of micro-plastics (MPs), are generally 0.05–5 mm in size, and due to their small size they are frequently consumed by aquatic organisms. As a result, widespread MPs infiltration is a global concern for the aquatic environment, posing a threat to existing life forms. MPs easily bind to other toxic chemicals or metals, acting as vector for such toxic substances and introducing them into life forms. Polyethylene, polypropylene, polystyrene, and other polymers are emerging pollutants that are detrimental to all types of organisms. The main route for MPs into the aquatic ecosystems is through the flushing of urban wastewater. The current paper investigates the origin, environmental fate, and toxicity of MPs, shedding light on their sustainable remediation.Graphical abstract

Sonochemistry fabrication of Er2Sn2O7 nanoparticles with advanced photocatalytic performance of their carbonic nanocomposites

The insufficiency of clean water sources has become a perilous tension for the future of the world that one of the eco-friendly and cost-effective solutions is the photocatalytic process for removal of artificial dyes and poisonous organic impurities. In the current research, a simple sonochemistry process was accomplished to gain Er 2 Sn 2 O 7 (ESO) nanoparticles with progressive photo-catalytic proficiency. Various surfactants of cationic Cetyl Trimethyl Ammonium Bromide (CTAB), anionic Sodium dodecyl sulfate (SDS) and polymeric polyethylene glycol 6000 (PEG 6000) were utilized to the creation of pure Er 2 Sn 2 O 7 nanoparticles. The figure and dimension of products were studied by various characterization procedures of spectroscopic and microscopic. The photo-degradation performances of the pure Er 2 Sn 2 O 7 nanoparticles prepared in different conditions were tested to remove of diverse synthetic dyes. Carbon-based nanocomposites of graphitic carbon nitrides (g-C 3 N 4 ), graphene quantum dots (GQDs) and graphene oxide (GO) present enhanced photocatalytic activities. The outcome of the catalyst size, type of dye, kind of carbon structure and scavenger kind was labeled on modifying ability of Er–Sn–O nano-catalyst task. Optimized Er 2 Sn 2 O 7 /g-C 3 N 4 nanocomposites have an efficiency of 93.9% for degradation of acid red dye that OH radicals support photo-degradation of contamination. • Synthesis of Er 2 Sn 2 O 7 nanoparticles via rapid ultrasonic technique. • Investigation of diverse synthesis circumstances on dimension properties of nanostructures. • Consideration of photo-degradation efficiency of Er–Sn–O nanostructures in different experimental conditions. • Investigation of photocatalytic mechanism of Er 2 Sn 2 O 7 /g-C 3 N 4 nanocomposites and kinetic study.