Low-density Polyethylene Composites Research Articles

Enhanced properties of low-density polyethylene composites reinforced with Bridelia ferruginea fibers: effect of low temperature fiber acetylation

In this study, lignocellulosic fibres were extracted from Bridelia ferruginea (BF), a shrub which can be found in sub-Saharan Africa with a view to probing the potential application of the fibres. The chemical properties of the BF were chemically modified by acetylation to evaluate the potential applications of the fibre reinforced polymer composites. The unacetylated and acetylated fibres were characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Thermogravimetric Analysis (TGA) to compare thermal and crystallographic properties after acetylation over different lengths of time. The acetylated fibres with the most promising properties were used for the fabrication of a polymeric composite. The mechanical properties of the fibre-reinforced polymer composites were studied by hardness and dynamic mechanical measurements. Four types of polymeric samples were prepared for the mechanical measurements: unreinforced polymer (Control) polyester, ATBF/LDPE, ACEBF3/LDPE, ACEBF/LDPE. The SEM micrographs revealed that acetylation led to defibrillation. FTIR peaks at 1250 cm−1 and 1371 cm−1 confirmed that acetylation had occurred. The fibres possessed high crystallinity index of 75% which reduced as time of acetylation increased. Acetylation at mild conditions of 70 °C for 3 h did not result in significant damage to the fibres. For the hardness measurements, the values of the micro-hardness of the composite samples increased from 0.20 GPa to 0.29 GPa. The acetylated fibres tend to further resist deformation due to its dispersion in the polymer matrix providing a stronger cross-linking effect. The properties unearthed show that BF appears to be a promising raw material for the production of polymer composites.

Correction to: Photoluminescence of Low-Density Polyethylene Composites with the CaGa2S4:Eu2+ Phosphor

Correction to: Photoluminescence of Low-Density Polyethylene Composites with the CaGa2S4:Eu2+ Phosphor

Using the potential of Canadian goldenrod (Solidago canadensis) as a functional filler with antioxidant activity of low-density polyethylene composites as an example of sustainable development of an invasive plant

Novel bio-based low-density polyethylene (LDPE) composites have been manufactured using different Canadian goldenrod (CG) invasive plant parts. Fragmented and ground blossoms (CGB) and mixed leaves and stems (CGSL) were used as fillers introduced by melt mixing into an LDPE matrix at various concentrations (2, 5, 10, 20, 40 wt%). Moreover, the influence of a series of modified fillers based on stems and leaves saturated with an extract made of blossoms (CGSL+E) on LDPE has been verified. The oxidation resistance of composites was enhanced based on the oxidation induction time (OIT) assessment, which increased from 0.5 min for LDPE to 178 min (CGB), 231 min (CGSL), and 140 min (CGSL+E). All composite series formed by compression molding were exposed to UV-light radiation using Xenon lamps and subjected to spectroscopic (FTIR) analysis, color assessment, and mechanical testing. LDPE/CGSL+E composites demonstrated the most favorable mechanical properties after UV-light exposure. In their case, an increase in Young modulus of 360 MPa was observed for the 40 wt% sample (PE ∼ 180 MPa) and an acceptable decrease in tensile strength of 6.5 MPa compared to the reference LDPE of 9.8 MPa. The study consists of a screening for future research on the use and simultaneous valorization of the invasive plant into functional composite fillers with increased oxidation resistance.

Preparation of effective antibacterial composites of low-density polyethylene modified with quaternary ammonium functionalized zinc oxide nanoparticles

Preparation of effective antibacterial composites of low-density polyethylene modified with quaternary ammonium functionalized zinc oxide nanoparticles

The effects of cassava peel content on mechanical properties of low-density polyethylene (LDPE) composites

The effects of cassava peel content on mechanical properties of low-density polyethylene (LDPE) composites

Potentialities of cellulose nanofibers (CNFs) in low density polyethylene (LDPE) composites

Potentialities of cellulose nanofibers (CNFs) in low density polyethylene (LDPE) composites

Effect of Different Compatibilizers on the Properties of Green Low-Density Polyethylene Composites Reinforced with Bambusa Vulgaris Bamboo Fibers.

Low-density green polyethylene (LDGPE) composites reinforced with 5 wt% of bamboo fiber and 3 wt% of a compatibilizing agent (polyethylene grafted with maleic anhydride and tannin) were processed through extrusion and injection molding. Bamboo fiber, Bambusa Vulgaris, was characterized using Fourier-transform infrared spectroscopy (FTIR). The molded specimens were analyzed for their thermal, mechanical, and morphological properties. The estimated concentration was chosen to provide the best mechanical strength to the material studied. FTIR analysis of the fibers revealed the presence of groups characteristic of bamboo fiber and tannin. Differential scanning calorimetry revealed that both compatibilizing agents increased the matrix's degree of crystallinity. However, scanning electron microscopy (SEM) showed that, despite the presence of compatibilizing agents, there was no significant improvement in adhesion between the bamboo fibers and LDGPE.

DC assisted electric field on the improvement of the nonlinear electrical conductivity of SiC/LDPE field grading composites

Nonlinear resistive field grading material presents nonlinear electrical conductivity, and self-homogenizes the electric field distribution. The nonlinear conductivity is closely associated to the filler distribution, which can be modulated by the electric field assist during the material preparation. In this paper, the effects of the direct current (DC) electric field assist on the filler distribution and nonlinear conductivity of the nonlinear resistive field grading materials were studied for the first time. The silicon carbide (SiC)/low-density polyethylene (LDPE) composites were prepared under different DC assisted electric field. The composites’ microstructure, dielectric spectra and DC conductivity were characterized, respectively. Results illustrate that the DC electric field assist leads to the gradient distribution of SiC filler in the matrix, and also contributes to the SiC particles’ chains. Compared with the untreated SiC/LDPE composite, the electric-field assisted composites show more distinct nonlinear conductivity characteristics when the DC assisted electric field exceeds 0.3 kV mm−1, which is attributed to the percolation phenomenon of SiC particles. This work is helpful to design the dielectric functionally graded materials, and to self-homogenize the electric field distribution in power apparatus and electronic devices.

Lead sulfide quantum dot-linear low-density polyethylene composites for near-infrared Mini-LEDs

Lead sulfide quantum dots (QDs), presenting near-infrared (NIR) emissions, have gained extensive interest within the realm of NIR light-emitting diodes (LEDs). However, the intricate surface defect passivation poses a major impediment that curbs broader applications of PbS QDs. To address it, we introduce linear low-density polyethylene (LLDPE) as a facilitating agent for the aggregation of PbS QDs, aiming to improve their optical properties by harnessing a stress-inducing effect. Compared to the bare PbS QDs that are luminescence silent, the PbS aggregates formed with the addition of LLDPE show a notable photoluminescence quantum yield (PLQY) as high as 20.7 %. Moreover, the presence of LLDPE mitigates the oxidative degradation of lead ions on the PbS QD surface, thereby enhancing the stability of the PbS QDs through steric hindrance. Near-infrared nini-LEDs are demonstrated by combining the PbS QD/LLDPE composites with blue mini-LED chips, which show an emission maximum of 1517.9 nm, a full width at half maximum (FWHM) of 297.6 nm and an energy conversion efficiency (ECE) of 14.6 %. The proposed method opens up new avenues for enhancing the optical properties of PbS QDs without using traditional passivation procedures.

Barium titanate exposure on metallographic and mechanical performance of coir fiber made low‐density polyethylene composite

AbstractTechnological growth and biodegradable waste natural fibers are significant choices in polymer matrix composite preparation because of their distinct qualities from monopoly matrix. During the fabrication process, the natural fiber faces poor compatibility and lack of adhesive behavior, resulting in reduced tensile strength and stiffness of the composite. The theme of the research is expanding the mechanical behavior of low‐density polyethylene (LDPE) composite by the exposure of sodium hydroxide‐treated coir fiber (CF) and barium titanate (BaTiO3) through an injection molding route. Influences of CF and BaTiO3 on metallographic, tensile, flexural, and impact strength and microhardness of LDPE composite are evaluated, and its outcomes are compared with mono LDPE. The surface morphology of the developed composite is exposed to homogenous dispersion of BaTiO3 with effective adhesive bonding with CF, which facilitates superior mechanical properties. The LDPE hybrid composite consists of 30 wt% CF and 2.5 wt% of BaTiO3 and is exploited about 69 ± 1.5 MPa of tensile strength, 54 ± 0.5 MPa of flexural strength, 4.9 ± 0.01 J of impact energy, and 31 ± 1.5HV of microhardness, this is greater than the mono LDPE (unreinforced). The enriched LDPE hybrid composite is suggested for automotive dashboard applications.

Synthesis and Behavior Study of Basalt Fiber-Made Low-Density Polyethylene Composites Via Injection Mold

Synthesis and Behavior Study of Basalt Fiber-Made Low-Density Polyethylene Composites Via Injection Mold

Preparation and properties of multilayer core-shell structure ammonium polyphosphate synergistic with THEIC for flame retardant LDPE

In this paper, a new type of highly efficient intumescent flame-retardant low-density polyethylene composite was prepared using two key technologies, namely, microencapsulation encapsulation technology and novel carbon formation technology. Precisely, β-cyclodextrin encapsulated modified ammonium polyphosphate@melamine formaldehyde resin (β-CDMCAPP@MF) was prepared by using Si-IFR synergistic flame retardant effect combined with the gel-solution method, and then flame retardant low-density polyethylene (LDPE) was prepared by compounding with tris-(2-hydroxyethyl) isocyanate (THEIC). The results showed that β-CDMCAPP@MF was modified with MF, β-CD, and silica coating. This modification resulted in excellent hydrophobicity and good compatibility with LDPE. The addition of IFR containing β-CDMCAPP@MF significantly improved the flame retardancy of the LDPE composites. Specifically, when 30 wt% of β-CDMCAPP@MF was added, the ultimate oxygen index of the composites reached 24.7 %, and V-0 grade and the tensile strength went 11.41 MPa. Compared with IFR/LDPE with the same proportion of MF@MCAPP and β-CD@MCAPP, the ultimate oxygen indices were increased by 9.72 % and 12.15 %, respectively. The introduction of THEIC into the flame retardant system resulted in a LOI value of 36.5 % and an FRI value of 2.523, which is 32.33 % higher than that of the composites containing 30 wt% of the flame retardant system (without THEIC). Cone calorimetry test results showed that introducing β-CDMCAPP@MF and THEIC significantly improved the smoke emission.

Polymer Composites of Low-Density Polyethylene (LDPE) with Elongated Hematite (α-Fe2O3) Particles of Different Shapes

Due to the intensive search for new types of advanced polymer materials for targeted applications, this work offers insight into the properties of low-density polyethylene/hematite composites. The specific feature of this study lies in the use of elongated hematite particles of different shapes. Uniform ellipsoid-, peanut- and rod-shaped hematite particles were hydrothermally synthesized and incorporated into the polymer matrix of low-density polyethylene (LDPE). LDPE/hematite composites are prepared by melt mixing. Hematite particles are characterized by scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD). The pure LDPE polymer and LDPE/hematite composites were studied by FT-IR and UV-Vis-NIR spectroscopy and by thermogravimetric analysis (TGA). The determination of the mechanical and barrier properties was also carried out. The obtained results indicate the influence of the elongated particles on the improvement of LDPE properties. An increase in thermal stability and UV-absorption was observed as well as the improvement of mechanical and barrier properties. The improvement of the composites’ properties in comparison to the pure LDPE is especially visible in the composites prepared with low content of hematite (0.25%). LDPE/hematite composites have promising characteristics for application as packaging materials with enhanced mechanical, thermal and barrier properties as well as UV-protective materials.

Effect of lignocellulosic corn stalk on mechanical, physical, and thermal properties of injection moulded low density polyethylene composites: An approach towards a circular economy

Escalating concern over global warming, which is mostly associated with deforestation, has led to the development of new classes of materials that can replace wood and better utilise natural resources. Presently, waste is a significant factor in recycling. In this regard, one of the leading contributors to waste is agricultural waste, which includes dried branches, leaves of trees, plants, and other organic materials. In the current study, waste from corn agriculture was utilised as a potential reinforcement for the fabrication of corn stalk-low density polyethylene (CS-LDPE) composites via an injection moulding technique at 170 °C. The different parameters were assessed to develop composites using CS, including physico-chemical, macromolecular, mineralogical, elemental, and morphological analysis. The amount of corn stalk (CS) was varied from 10 to 50 wt% with respect to the polymer. The mechanical, physical and thermal performance of the composites was examined. The density and water absorption of the composites were found to remain within the ranges of 1.00–1.11 g/cm3 and 0.22–1.01 %, respectively, whereas these parameters increased as the proportion of CS increased. The thermal conductivity decreases with the addition of CS from 0.36964 ± 0.020 to 0.22388 ± 0.002 W/mK. It was observed that adding CS to the composites increased their tensile and flexural properties, but decreased their impact strength. The maximum flexural strength of 14.40 ± 1.558 MPa, flexural modulus of 752.53 ± 180.409 MPa, tensile strength of 10.49 ± 0.946 MPa and tensile modulus of 539.79 ± 91.044 MPa were observed with a 50 % CS content. The results suggest that these materials have considerable potential to serve as a cost-effective substitute for the conventional lignocellulosic fillers in the manufacturing of wood-plastic composites.

Utilization of Ananas comosus Crown Residue Husk as a Sustainable Strength Additive for EPR/LDPE Blend Composites.

The utilization of waste generated by natural resources is a crucial problem nowadays. The current study describes the utilization of pineapple (Ananas comosus) crown residue husk (PCRh) as a strength additive for low-density polyethylene (LDPE) and ethylene propylene rubber (EPR) composites. The blend composites with 30% husk, 10 wt % EPR, and 60% LDPE content showed much better mechanical properties, such as tensile strength and flexural properties, than pristine LDPE and its binary composite with 10 wt % EPR. The high tensile strength (∼19.28 MPa) and tensile modulus (522.97 MPa) were obtained for the composite consisting of 30 wt % PCRh in the basic polymer matrix. Similarly, the highest flexural strength (∼18.09 MPa) and modulus (∼790.29 MPa) were recorded for the same composition. The incorporation of PCRh with LDPE and EPR was further characterized by attenuated total reflection-Fourier transform infrared, differential scanning calorimetry, field emission scanning electron microscopy, dynamic mechanical analysis, and a universal testing machine to evaluate its impact on various properties.

Ecofriendly Biochar as a Low-Cost Solid Lubricating Filler for LDPE Sustainable Biocomposites: Thermal, Mechanical, and Tribological Characterization

The potential of ecofriendly biochar, a carbon-rich byproduct of biomass pyrolysis, as a low-cost solid lubricating filler for low-density polyethylene (LDPE) sustainable biocomposites is investigated in this work. Tensile strength, hardness, thermogravimetric analysis (TGA), melting flow index (MFI), tensile test, flexural test, and frictional tests were used to characterize the biocomposites’ mechanical, thermal, and tribological properties. Energy-dispersive X-ray spectroscopy (EDS) was used to assess the chemical composition of the biochar, while field-emission scanning electron microscopy (FESEM) was used to capture the biochar morphology. The results showed that the incorporation of biochar in LDPE matrix increased the mechanical characteristics of the biocomposites and resulted in a significant increase in tensile strength, flexural strength, and hardness. More specifically, the LDPE+10 wt% composite outperformed the pure LDPE matrix by 1.9% in tensile strength and 47% in flexural strength. Furthermore, integrating biochar into LDPE composites enhances thermal stability, lowers the melt flow index (MFI), and boosts the hardness by 24.3% for the composite with 10% biochar content. Furthermore, biochar improves wear resistance and durability, with the LDPE10 composite exhibiting a friction coefficient that is 56.3% lower than pure LDPE. These findings indicate that biochar is a viable, cost-effective, and environmentally friendly filler for improving the performance of LDPE-based biocomposites for many varieties of applications.

Study on the effect of novel intumescent flame retardant composed of β-cyclodextrin modified ammonium polyphosphate and THEIC on the flame retardancy of LDPE composites

Enhancing polymer flame retardancy is crucial for lowering combustion-related exothermic heat and flue gas production. β-cyclodextrin microencapsulated ammonium polyphosphate (β-CD@APP) were synthesis through in-situ polymerization and combined with 1, 3, 5-tris (2-hydroxyethyl) isocyanurate (THEIC) as a novel intumescent flame retardant (IFR) to enhance the flame retardancy of low density polyethylene (LDPE). The results showed that APP's hydrophobic characteristic increased, which enhanced its polymer dispersibility. Compared with LDPE, the LOI value of β-CD@APP/THEIC/LDPE (LDPE5) was enhanced from 17.5% to 28.7% and the composites could meet the UL-94 V-0 standard. Smoke volume and thermal decomposition rate were reduced. Furthermore, a stable char layer was found, which can be seen from the SEM of the char slag and the Raman results. According to the above results, the thermal decomposition and possible mechanism of flame retardants in LDPE composites during combustion were studied.

The evaluation of waste engine oil/old newspaper in recycled low density polyethylene composites

AbstractThe study investigates changes in the mechanical, thermal, morphological and physical properties of recycled low density polyethylene (LDPE) composites made with percentages (10 wt%, 20 wt%, 30 wt.%) of old newspaper fiber (ONF) and waste engine oil (WEO) (1 wt.%). The composites were manufactured by a single screw extruder. Adding WEO up to 20 wt% of ONF had a positive effect on the flexural properties, while the incorporation of WEO up to 10 wt % of ONF showed an affirmative effect on the tensile properties of the composites. The highest flexural strength was achieved in A3 (13.19 MPa) and B3 (12.3 MPa) samples for ONF added composites and ONF/WEO composites, respectively. Adding to the WEO decreased the water absorption values of the recycled low density polyethylene composites. Differential scanning calorimetry analysis showed that the addition of 1% WEO, the crystallinity of the composites decreased to about 30%. In the light of the results, the WEO could be successfully used with old newspaper in a polyethylene matrix.Highlights The highest tensile strength was achieved in the B3 sample (with WEO). The highest flexural strength was achieved in the B3 sample (with WEO). The highest tensile was obtained from the A3 sample (without WEO). The highest flexural strength was obtained from the A3 sample (without WEO). The crystallinity of the composites decreased to about 30%.

Antibacterial and Biocompatible Polyethylene Composites with Hybrid Clay Nanofillers.

Low-density polyethylene is one of the basic polymers used in medicine for a variety of purposes; so, the relevant improvements in functional properties are discussed here, making it safer to use as devices or implants during surgery or injury. The objective of the laboratory-prepared material was to study the antimicrobial and biocompatible properties of low-density polyethylene composites with 3 wt. % hybrid nanoclay filler. We found that the antimicrobial activity was mainly related to the filler, i.e., the hybrid type, where inorganic clay minerals, vermiculite or montmorillonite, were intercalated with organic chlorhexidine diacetate and subsequently decorated with Ca-deficient hydroxyapatite. After fusion of the hybrid nanofiller with polyethylene, intense exfoliation of the clay layers occurred. This phenomenon was confirmed by the analysis of the X-ray diffraction patterns of the composite, where the original basal peak of the clays decreased or completely disappeared, and the optimal distribution of the filler was observed using the transmission mode of light microscopy. Functional property testing showed that the composites have good antibacterial activity against Staphylococcus aureus, and the biocompatibility prediction demonstrated the formation of Ca- and P-containing particles through an in vitro experiment, thus applicable for medical use.

Effect of the melt flow index of compatibilizer on the melt processing and properties of highly filled magnesium hydroxide/linear low density polyethylene composites

AbstractThe application of highly filled composites is limited by their poor processing and rheological properties due to the high loading of fillers. One possible solution to this problem is to use maleic anhydride grafted polypropylene (MAPP) with high melt index as compatibilizer and lubricant. Herein, magnesium hydroxide (MH)/linear low‐density polyethylene (LLDPE) composites with 60 wt% of MH were prepared using MAPP with three different melt flow indexes (MFI). The equilibrium torque and melt flow index tests show that the addition of MAPP with high MFI significantly improves the processability and flowability of MH/MAPP/LLDPE composites. The rheological studies show that it also leads to a substantial reduction in the viscosity and therefore MH/MAPP/LLDPE composites exhibit more solid‐like responses. The scanning electron microscopy shows that a transition layer is formed at the MH‐LLDPE interface. The flame retardancy test shows that the addition of MAPP slightly reduces the flame retardancy of the composites as evidenced by the reduced limiting oxygen index and increased total heat release. Cone calorimeter test shows that the simultaneous addition of MH and MAPP has a synergistic smoke suppression effect.