Low-density Polyethylene Fibers Research Articles

Do microplastics accumulate in penguin internal organs? Evidence from Svenner island, Antarctica

The prevalence of microplastics (MPs, <5 mm) in natural environments presents a formidable global environmental threat MPs can be found from the Arctic to Antarctica, including glaciers. Despite their widespread distribution, studies on MP accumulation in apex predators inhabiting Polar Regions remain limited. The objective of this study was to conduct a comprehensive examination, for the first time, of MP bioaccumulation in various organs and tissue of Adélie penguins. This investigation comprehends the gastrointestinal tract (GIT), scat, internal organ (lung, trachea, spleen, and liver) and tissue (muscle) samples collected from Svenner Island, Antarctica during the 39th Indian expedition to Antarctica in 2019–2020. Our analyses revealed the presence of 34 MPs across the GIT, scat, lung, and trachea samples, with no MPs detected in muscle, spleen, or liver tissues. Blue-colored microfibers (>50 %) and MPs smaller than 1 mm (38 %) in size were prominently observed. Polymer characterization utilizing μ-FTIR spectroscopy identified low-density polyethylene (LDPE) (~63 %) as the predominant polymer type. The accumulation of MP fibers in the gastrointestinal tract and scat of Adélie penguins may originate from marine ambient media and prey organisms. Furthermore, the presence of LDPE fibers in the trachea and lungs likely occurred through inhalation and subsequent deposition of MPs originating from both local and long-range airborne sources. The identification of fibers ranging between 20 and 100 μm within the trachea suggests a plausible chance of cellular deposition of MPs. Overall our findings provide valuable insights into the organ-specific accumulation of MPs in apex predators. Adélie penguins emerge as promising environmental bio-monitoring species, offering insights into the potential trophic transfer of MPs within frigid environments.

Effect of Mass Fraction on Leaching Kinetics of Hydrophobic Ultraviolet Stabilizers in Low-Density Polyethylene.

The leaching kinetics of five hydrophobic ultraviolet (UV) stabilizers from low-density polyethylene (LDPE) (micro)fibers into water was evaluated in this study, with variation of the mass fraction (ω = 0.1-2.0 wt %) of the stabilizers. A one-dimensional convection-diffusion model for a cylindrical geometry, requiring partitioning between the LDPE fibers and water (KLDPEw) and the internal diffusion coefficients (DLDPE), was used to evaluate the leaching process and the leaching half-life of the target UV stabilizers at ω < 0.5 wt % (Case I). Diffusion through the aqueous boundary layer is the rate-determining step, and the leaching half-life is predicted to be very long (a few months to years) under unaffected conditions. When the UV stabilizers are supersaturated within LDPE fibers (i.e., ω > 0.5 wt %, Case II), the possible formation of a surficial crystal layer of the additives on the LDPE fiber extends the time scale for leaching compared to that in Case I due to the requirement of overcoming the crystallization energy. This study provides a fundamental understanding of the leaching profiles of plastic additives for assessing their potential chemical risks in aquatic environments; further studies under the relevant environmental conditions are required.

Effect of different types and shapes of microplastics on the growth of lettuce

The presence of microplastics in agricultural soils has emerged as a significant environmental concern due to their persistent nature. Microplastics of different properties (i.e., types, shapes, size, concentration) are present in the environment, but the studies on the effect of microplastics having different properties are limited. Thus, this study investigated the effects of different microplastics (low-density polyethylene (LDPE) fragments, polyvinyl chloride (PVC) fragments, and LDPE fiber) in soil on the growth of lettuce (Lactuca sativa L.). Pot tests were carried out to study the effect of a range of microplastic concentrations and different shapes and types of microplastics in soil on the lettuce growth. The different growth parameters such as lettuce weight, lengths, and chlorophyll contents were measured and compared. The results showed that the adverse effects of the microplastics on the lettuce growth increased with increasing microplastic concentration. The effects of LDPE fragments and fibers on the root weights and the chlorophyll contents were microplastic shape-dependent. Also, the effects of LDPE fragments and PVC fragments on the shoot and root weights and the chlorophyll contents were microplastic type-dependent. Among the three microplastics studied, LDPE fragments tend to have greater effects on the lettuce growth than the other microplastics. Overall, the results show that the effects of microplastics on different growth parameters of lettuce can be shape- and/or type-dependent. The presence of microplastics having different properties make the understanding the effects of microplastics on plants difficult, and this necessitates further studies.

Melt-Electrospun Polyethylene Nanofiber Obtained from Polyethylene/Polyvinyl Butyral Blend Film.

We prepared low-density polyethylene (LDPE) nanofiber, a few hundred nanometers in diameter, using polyvinyl butyral (PVB) and a laser melt-electrospinning (M-ESP) device. We blended PVB with LDPE via an internal melt mixer, removed the PVB after M-ESP by ethanol treatment, and studied the influence of PVB on fiber diameter. A substantial diameter reduction with improved crystallinity of LDPE fiber was observed with increased PVB content in the blend. PVB inclusion also increased the polarity of the LDPE/PVB blend, resulting in better spinnability. The removal of PVB from LDPE/PVB blend fiber caused a massive drop in the LDPE fiber diameter, due to fiber splitting, particularly in PVB-rich samples. Fourier transform infrared (FTIR) spectroscopy of fibers confirmed that the prepared nanofiber was the same as pure LDPE fiber.

Electrospinning of tri-acetyl-β-cyclodextrin (TA-β-CD) functionalized low-density polyethylene to minimize sulfur odor volatile compounds

Abstract The study explored a new odor control method using Low-density polyethylene (LDPE) and Triacetyl- β-cyclodextrin (TA-β-CD) functionalized fiber mat. The odor control system was prepared using an electrospinning process. Based on the image obtained from a scanning electron microscope (SEM), the fiber diameter of the pure LDPE and TA-β-CD loaded LDPE fibers were found about 1.31–4.92 μm, depending on the TA-β-CD concentration. The presence of TA-β-CD in the fibered film mat was verified using FTIR. Hydrophobicity of the fiber mat was measured by water contact angle (WCA). The result indicates a slight inverse relationship between WCA and TA-β-CD concentration after 5% loading. Finally, the odors absorbing effectiveness of this system was examined using GC–MS. Three target sulfur odor compounds, including dimethyl disulfide (DMDS), dimethyl sulfide (DMS), and carbon disulfide (CDS), were effectively removed using the TA-β-CD functionalized LDPE fiber mat. Especially, the reduction of DMDS was up to 90.33%. The result suggested that tailoring electrospun LDPE and TA-β-CD fiber mat has a strong potential to be used as an active packaging material to develop the off-odor removal system for food or healthcare packaging application.

Potential Use of Plastic Wastes for Low Thermal Conductivity Concrete.

The use of plastics has increased over the years, thus resulting in a large volume of plastic waste being generated and accumulated in the environment. Due to its non-biodegradability and persistence, recycling processes have become one of the sustainable solutions for preventing environmental deterioration. Plastic wastes, including high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), and polyethylene terephthalate (PET), were collected from industrial sector and used as additional ingredients to improve concrete properties. Prior to concrete processing, an increase in wettability of plastic fibers using nonionic surfactant, Dehydol LS-12, was investigated. At the optimal concentration of 10 times of the critical micelle concentration (CMC), an interfacial tension and a contact angle were reduced to 31–32 mN/m and 65°–68°, respectively. Properties of concrete were determined and compared to those of the mortar samples. Porosity was found to increase with higher volume fraction of plastic fibers, whereas decreases in workability, bulk density, thermal conductivity, splitting tensile strength, and compressive strength were encountered. The lowest thermal conductivity was recorded for concrete samples prepared with 30% by volume of LDPE fibers, and the rest in descending order were HDPE, PP, and PET, respectively. Furthermore, the maximal inclusions of plastic fibers were 5% for HDPE and LDPE, 10% for PP, and 50% for PET so as to satisfy the precast concrete wall requirements.

멜트블론을 이용한 올레핀계 접착층의 특성에 관한 연구

This study investigated the interrelationships between some properties of low-density polyethylene (LDPE) web fibers produced by the melt-blown technique. Variations in the LDPE fiber's diameter and uniformity were correlated against variations in throughput pressure, hot air pressure, and nozzle temperature. The bond strength of the LDPE web adhesion layer was found to be lower than that of LDPE film. However, the LDPE web adhesion layer's air permeability was found to be significantly higher than - as much as 260 times higher - that of LDPE film. The results suggest that melt-blown LDPE web fibers are useful for producing multi-function products.

Enhancement of uranium extraction from seawater using chromic-acid-treated amidoxime adsorbent prepared by simultaneous irradiation grafting technique

Enhancement of uranium extraction from seawater using chromic-acid-treated amidoxime adsorbent was studied. Chromic-acid-treated amidoxime fibers were synthesized based on the simultaneous irradiation grafting method at a low temperature. Low-density polyethylene (LDPE) fibers were treated with chromic acid for up to 90 minutes. After the treatment, the fibers were submerged in 60:40 acrylonitrile:methacrylic acid monomer by volume and irradiated with 40 kGy γ-ray. The maximum grafting efficiency of about 90% occurred at 20 minutes of acid treatment time, as a significant enhancement of 30% compared to the literature-reported value of about 70%. When submerged in shallow seawater with an average temperature of 30 °C for 4 weeks, the amidoxime adsorbent exhibited the adsorption capacity of 2.06 g-U/kg-adsorbent, which was 37% higher than the literature-reported value. These significantly increased grafting and adsorption efficiencies were attributed to the increased surface area of chromic-acid-etched LDPE fibers. Moreover, for the submersion up to 8 weeks, the adsorption increased to 2.15 g-U/kg-adsorbent. The adsorption capacity was evaluated to reduce to about 65% after eight cycles of repeated usage. Uranium concentrations in Thailand's seawater collected at various depths and locations were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) to be about 3 ppb everywhere.

열매유형 용융전기방사장치를 이용한 폴리에틸렌 혼합물의 용융점도와 섬유직경의 상관관계 연구

Electrospinning has gained interests as a polymer processing technique for nanofiber fabrications. It is well known that both polymer solutions and polymer melts can be electrospun. Among them, melt electrospinning is envi- ronmentally friendly technique due to the absence of solvent. However, the diameter of melt-electrospun fibers is typ- ically thicker than solution-electrospun fibers. By using a home-made melt-electrospinning device, micron-sized fibers with smooth and even surfaces were electrospun successfully. We demonstrate that low-density polyethylene fibers can be reduced in diameter with a viscosity-reducing additive such as low molecular weight polyethylene monoalcohol and polyethylene wax. The diameter was further reduced by blending it with oxidized polyethylene wax due to polarity increment. Additionally, parameters affecting the diameter were analyzed such as an applied voltage and a spinning dis- tance.

Property and Structure of Novel Absorptive Fiber Prepared by Blending Butyl Methacrylate-Hydroxyethyl Methacrylate Copolymer with Low Density Polyethylene

A novel absorptive fiber based on butyl methacrylate (BMA)-hydroxyethyl methacrylate (HEMA) copolymer and low density polyethylene (LDPE) was prepared by the method of gelation-spinning in twin screw extruding machine, swelling behavior, thermal behavior, crystallization behavior and nonisothermal crystallization kinetics were investigated, finally, the morphology structure for the cross-section was observed by SEM. The results show that the saturated absorbency for the blend fiber gradually decreases with increasing mass fraction of LDPE in mixture ratio from 10 wt% to 30 wt%. The results analyzed by DSC and WAXD show that crystallization and melting behaviors for the blend fiber are similar to those for pure LDPE fiber, and the crystallinity for the blend fiber decreases with decreasing mass fraction of LDPE. The results observed by SEM show that the cross-section for BMA-HEMA copolymer fiber shows a mono-phase structure with many cavities, as mass fraction of LDPE increases from 10 wt% to 30 wt%, the morphology structure with one continuous phase is transformed into another structure with two continuous phases, and the number of the cavities in the cross-section decreases, finally, the cross-section for LDPE fiber again shows a mono-phase structure without any cavities.

Effect of heating–cooling cycle on the opto‐structural properties of low‐density polyethylene fibres using two‐beam interference microscopy

A hot stage attached with a two‐beam interference (Pluta) microscope was used to apply a heating–cooling cycle (HCC) on low‐density polyethylene fibres (LDPE). The variation of the refractive indices (n ∥ and n ⊥) with the temperature was carried out during the heating and cooling of the LDPE fibres. The activation energy (E a) and thermooptic coefficient (dn/dT) were calculated for the investigated LDPE fibres. The spectral dispersion curves, percent crystallinity and orientation function were determined for the treated LDPE fibres. It was found that the HCC for LDPE fibre implies: a reversible behaviour of both optical and structural properties against temperature and an improvement in the fibre crystallinity.

Short fiber formation during extrusion of polyethylene–sodium lignosulfonate blends

AbstractWhen extruding a blend of low density polyethylene (LDPE) and a technical grade of sodium lignosulfonate through a capillary it was observed that LDPE formed fibers in a matrix of the lignosulfonate. With short capillaries and low shear rates, short fibers of LDPE with lengths between 0.5 and 5 mm and with diameters in the range 2–20 μm can be produced. Since sodium lignosulphonate is water‐soluble, the LDPE fibers can easily be isolated. Such fibers can be used for synthetic wood pulp or in nonwoven types of applications.