Low-density Polyethylene Composites Research Articles

Role of Chemically Functionalization of Bamboo Fibers on Polyethylene-Based Composite Performance: A Solution for Recycling.

Low-density polyethylene is the most common polymer for manufacturing containers, bottles, tubes, plastic bags, computer components and so on. There is an urgent need to find solutions for its recycling and reintegration in high volume production components such as non-structural auto applications. The reinforcement of recycled low-density polyethylene with natural fibers represents a solution for the re-use of the recycled low-density polyethylene. However, there is a lack of understanding of how the natural fibers influence the behavior of the bare low-density polyethylene, and furthermore, how the interface between the fibers and the matrix can be controlled in composite to obtain the designed toughness, strength, stiffness and damping. In this sense, the study presents an in-depth analysis of the behavior of three coupling agents used in the chemically functionalized bamboo fibers interface for reinforcing low-density polyethylene composites. Through mechanical tests, the mechanical properties are determined and compared and finally, a correlation between the viscous behavior of the resulted composites and the toughening mechanism is proposed. The conclusion of the study enables a flexible design of polymer composite components fabricated of recycled and non-recycled low-density polyethylene and natural fibers.

Estimation of Microwave Absorption Properties of RGO-SiC-LLDPE Composites

The present work investigate the microwave absorption properties of reduced graphene oxide (RGO)-Silicon carbide (SiC)-Linear low-density polyethylene (LLDPE) composites prepared in different concentration of fillers(10, 20, 30, 40 wt. %) with LLDPE matrix. Synthesis of RGO is confirmed from XRD analysis and SiC is used as received from supplier. Complex permittivity of the composites is measured using Nicolson Ross method showing an increasing trend with increasing filler concentrations with maximum and for 40 wt. % composite sample. Based on transmission line theory and using measured value of complex permittivity, conductor backed single and double layer absorber is designed by thickness optimization. The calculated reflection loss (RLc) value of ~-71 dB at 11.23 GHz is observed for 40 wt. % composite sample of 7 mm thickness with -10 dB absorption bandwidth of 1.48 GHz and -20 dB bandwidth of 0.64 GHz.

Influence of Filler Surface Modification on Static and Dynamic Mechanical Responses of Rice Husk Reinforced Linear Low-Density Polyethylene Composites

Influence of Filler Surface Modification on Static and Dynamic Mechanical Responses of Rice Husk Reinforced Linear Low-Density Polyethylene Composites

Crosslinked Low-Density Polyethylene/Polyhedral Oligomeric Silsesquioxanes Composites: Effects of Crosslinker Concentration on the Mechanical, Thermal, Rheological, and Shape Memory Properties

The aim of this study was to produce crosslinked low-density polyethylene (LDPE) composites using peroxide and octavinyl polyhedral oligomeric silsesquioxane (OvPOSS) and to examine the shape memory behavior. The strategy was to use OvPOSS as a coagent to increase the crosslinking density and crosslinking efficiency while improving the mechanical and shape memory properties as well. The peroxide concentration, from 0.5 phr to 3.0 phr, was taken as the experimental parameter, with 4 phr OvPOSS added to all composites. The melt mixing route was applied similar to that which would be used industrially. The thermo-responsive shape memory properties near the melting point were examined in tension mode. The dispersion of OvPOSS in the LDPE matrix was observed via scanning electron microscopy and Si-mapping. In addition, the thermal, mechanical, structural, and rheological features of the novel LDPE/OvPOSS and LDPE/peroxide/OvPOSS systems were investigated. It was observed that the crosslinking density of LDPE increased in the presence of OvPOSS, which affected the mechanical, rheological and thermal properties and increased the shape recovery ratio of the LDPE.

ENVIRONMENTAL PROPERTIES OF ENVIRONMENTALLY FRIENDLY CONSTRUCTION MATERIALS: RECYCLED LDPE COMPOSITES FILLED BY BLAST FURNACE DUST

ABSTRACT This study focused on creating a sustainable composite material using blast furnace dust of the iron-steel industry and plastic wastes of the plastic industry in order to reduce the embodied energy of the material and generate more sustainable material. In this study, varying amounts of blast furnace dust (BFD), which is the primary iron-steel industry waste and which is used as filler for recycled low-density polyethylene (LDPE), was mixed to create the composite material. The embodied energy, emissions to water and air (volatile organic compounds) of BFD filled LDPE composites were determined. It was found that the composite materials had less embodied energy compared with polymer-based flooring materials such as epoxy, polyurethane (PU) and polyvinylchloride (PVC). In addition, it was determined that the composite material did not release emissions to water and have fewer total volatile organic compounds (TVOCs). These results showed that the produced composite material could be used in buildings as a sustainable floor coating material, thus saving raw materials and supporting indoor air quality and recycling.

Electrophysical Properties of Low-Density Polyethylene and Zeolite Composites

Electrophysical Properties of Low-Density Polyethylene and Zeolite Composites

Fabrication and analysis of physico-mechanical characteristics of NaOH treated PALF reinforced LDPE composites: Effect of gamma irradiation

Agro wastage pineapple leaf fiber (PALF) was treated with different weight/volume (w/v) concentrated (0.5, 3, 5, 7, and 10%) sodium hydroxide (NaOH) at 50 °C for 30 min. The corresponding values of weight loss, tensile properties, and density were evaluated. PALF treated with 7% NaOH showed considerably improved physico-mechanical properties. The treated fibers were used as randomly oriented reinforcement in low-density polyethylene (LDPE) filled bio-composite by maintaining a 1:1 ratio in terms of weight. The composite fabrications were done by heat press molding. Then the five categories of the sample were irradiated with gamma (Co-60) radiation beneath different doses (2.50–10.00 kGy) to increase the compatibility of fiber-matrix bonding. These irradiated samples were prepared for determining the different physico-mechanical properties such as tensile strength (TS), tensile modulus (TM), elongation at break percentage (EB%), bending strength (BS), bending modulus (BM), and impact strength (IS). Gamma dose of 7.50 kGy irradiated samples demonstrated the overall best result. SEM images of 7% NaOH treated PALF reinforced LDPE composites were analyzed at tensile fracture surface to understand the fibers pull out and fiber-matrix interface. Furthermore, the water absorption performance of the mentioned composite was also investigated at different day intervals. FTIR was used to explicate the changes of functional groups of PALF and those composites due to NaOH treatments and different levels of gamma doses respectively. TGA was performed to explore the comparatively enhanced thermal performance of 7% NaOH treated PALF containing composite sample irradiated at 5.00, 7.50, and 10.00 kGy gamma doses.

Mechanical and Surface Morphology Properties of Low Density Polyethylene Composites Filled with Organic Materials

The effects of coconut husk and mango seed shell filler blend which are considered as agricultural wastes on the mechanical properties of Low Density Polyethylene (LDPE) composites were studied. These fillers which are of plant origin, organic, cheap to acquire, available, and biodegradeable were incorporated into LDPE polymer resin for the fabrication of bio-degradeable LDPE polymer composites. Varying percentages of the fillers, 0%, 5%, 10%, 15% and 20% were added to the LDPE polymer resins to produce biodegradeable LDPE polymer composites through injection moulding machine. The mechanical properties such as tensile strength, flexural strength, compression strength and hardness test were tested for. The surface morphology of the composites was also tested for via scanning electron microscope. The results showed that the fillers had positive impacts on the mechanical properties of the polymer composites by improvement in the flexural strength and hardness. The use of such cheap, available and biodegradeable raw materials can decrease the high cost of production of LDPE products, and aid the production of more eco friendly polymer composites.

The effect of thermal, flammability, and mechanical properties of wood plastic composites made from recycled food-packaging LDPE and eco-friendly phytic acid

Within this work, a novel eco-friendly flame-retardant system for wood plastic composites (WPCs) was developed based on the phytic acid modified wood flour (WF) and the silane-coupling agents treated diatomite, were incorporated into low density polyethylene (LDPE) by a melt-blending process. Via impregnation process, neutralized phytic acid (PA(N)) was absorbed into the wood porous structure to obtain phytic acid modified wood flour (WF-PA(N)), which was expected to improve the retardancy and thermal stability of the WPC composites without deterioration of their mechanical properties. Moreover, polyethylene grafted maleic anhydride (MAPE) could render the phytic acid modified woods to be well dispersion in LDPE matrix, and consequently increasing the thermal resistance properties of the composites with increasing the content of the phytic acid modified woods. The TGA analysis revealed that the char yield of the LDPE/WF-PA(N) composites (22~29%) were higher than that of LDPE/WF (14%), indicating improved thermal stability by the addition of WF-PA(N). The heat distortion temperature (HDT) of the LDPE/WF-PA(N) composites exhibited upward with increasing WF-PA(N) contents. Among the LDPE/WF-PA(N) composites, the one containing 45% of WF-PA(N) exhibits the best tensile and impact strength. In addition, the burning rate analysis demonstrated that LDPE composites containing WF-PA(N) has short burning rates presumably ascribed to the formation of char layer from phosphorus-containing additives WF-PA(N). This is consistent with the results of TGA analysis.

Thermal stability and performance trends of sustainable lignocellulosic olive / low density polyethylene biocomposites for better environmental green materials

The current trend in deteriorating mechanical performance of green polymeric-based materials has made it essential for designers to establish more reliable and sustainable bio-products. Here, the mechanical performance of Jordanian lignocellulosic olive fibers in polymeric-based composites has been methodically investigated. The outcomes of different reinforcement conditions on the desired mechanical performance of the olive leaf’s lignocellulosic fibers with low-density polyethylene (LDPE) composites have been examined, including the properties of tensile strength, tensile modulus, mechanical strain, impact strength, and the intensity per composite volume. This has been accomplished to determine the optimum reinforcement condition for the desired mechanical behavior as well as to establish the performance deterioration and enhancement trends of such bio-materials in a more consistent manner. The results signify that lignocellulosic olive fibers have exhibited various enhancements in terms of mechanical performance. Both the tensile strength and modulus of elasticity have been dramatically improved at 20 wt.% fiber content. This was the most desired reinforcement condition among all considered cases. The olive fibers also possess the capability of maintaining relatively high ductility and impact strength properties, making them suitable for various industrial applications where high ductility is necessary. Thermal stability analysis using TGA and DTG has been employed to obtain accurate results.

Physical, mechanical and thermal properties of low-density polyethylene reinforced with PET-coated SBS paperboard shavings applying different processing conditions

Awareness about environmental problems has generated interest in the research for new materials in line with the sustainability principles. The recycling of industrial solid waste has contributed to the transformation of environmental liabilities into new products with added commercial value. In this study, the physical, me-chanical and thermal properties of low-density polyethylene (LDPE) composites reinforced with polyeth-ylene terephthalate (PET)-coated solid bleached sulfate (SBS) paperboard shavings were investigated ac-cording to composite formation process variables: preparation temperature, mean particle diameter of com-ponents and reinforcement concentration. Very few studies on the characterization of composites reinforced with PET-coated SBS paperboard shavings have been reported to date. The analyses were carried out based on standard methods published by the American Society for Testing and Materials. The results indicate an increase in the moisture content and water absorption occurred as a function of the increase in the rein-forcement. With regard to the density, there was no significant influence of variations in the granulometry or concentration of the PET-coated SBS paperboard shavings. Composites formed with particles of 0.73 mm at 140 ºC presented satisfactory tensile and flexural strength, compared with the values for the LDPE resin. Composites with 20% reinforcement formed by particles of 4.05 mm at 140 ºC showed 14% improvement in impact resistance properties. The thermal analysis indicated that shavings degradation occurred at 190 °C. Thus lower temperatures need to be applied in the processing of this composite material. The processing conditions of the composites resulted in different performance for each evaluated property. The use of the composite in manufacturing products must follow the process conditions that will provide to material the desirable level of properties for the best performance of the final product.

Physical, mechanical and thermal properties of low-density polyethylene reinforced with PET-coated SBS paperboard shavings applying different processing conditions

Awareness about environmental problems has generated interest in the research for new materials in line with the sustainability principles. The recycling of industrial solid waste has contributed to the transformation of environmental liabilities into new products with added commercial value. In this study, the physical, mechanical and thermal properties of low-density polyethylene (LDPE) composites reinforced with polyethylene terephthalate (PET)-coated solid bleached sulfate (SBS) paperboard shavings were investigated according to composite formation process variables: preparation temperature, mean particle diameter of components and reinforcement concentration. Very few studies on the characterization of composites reinforced with PET-coated SBS paperboard shavings have been reported to date. The analyses were carried out based on standard methods published by the American Society for Testing and Materials. The results indicate an increase in the moisture content and water absorption occurred as a function of the increase in the reinforcement. With regard to the density, there was no significant influence of variations in the granulometry or concentration of the PET-coated SBS paperboard shavings. Composites formed with particles of 0.73 mm at 140 ºC presented satisfactory tensile and flexural strength, compared with the values for the LDPE resin. Composites with 20% reinforcement formed by particles of 4.05 mm at 140 ºC showed 14% improvement in impact resistance properties. The thermal analysis indicated that shavings degradation occurred at 190 °C. Thus lower temperatures need to be applied in the processing of this composite material. The processing conditions of the composites resulted in different performance for each evaluated property. The use of the composite in manufacturing products must follow the process conditions that will provide to material the desirable level of properties for the best performance of the final product.

Mechanical and morphological properties of Citrus Maxima waste powder filled Low-Density polyethylene composites

Until recently, synthetic filler materials have been the preferred choice for reinforcement of polymers to improve its toughness. However, natural filler and fiber materials are emerging as suitable alternatives to synthetic materials for reinforcing polymers due to their environmental friendliness, high abundance, renewability, and cost-effectiveness. In the present study, the waste portion of the fruit Citrus Maxima (CM) commonly known as Pomelo, in the form of fine powder was blended with Low-Density Polyethylene (LDPE) for making the composite using the injection molding method. The peel of CM consists of a foamy portion which was separated, thoroughly dried at 50–70 °C and ground into a fine powder and was used as an eco-friendly particulate filler with the LDPE matrix in different proportions (0, 5, 10, 15, and 20 wt%) in treated and untreated form. The filler was treated with 2 wt% of Silane coupling agent. XRD and FTIR confirmed the cellulosic behavior of the CM foam. The effect of filler content on the mechanical properties of the untreated and treated composites was investigated. The morphology and the microstructure of the composites were observed by XRD, FTIR, and SEM. The surface treatment showed significant improvement in the tensile strength, % elongation and impact strength for the treated composite at higher loading of filler. The mechanical behaviour of the composites led to the successful utilization of CM waste portion for making an eco-friendly reinforcing additive to form LDPE composites.

Preparation and properties of modified aluminum diethylphosphinate flame retardant for low‐density polyethylene

AbstractTo improve the flame retardancy of low‐density polyethylene (LDPE) and mechanical properties of LDPE composites, phenol‐formaldehyde aluminum diethylphosphinate microcapsules (PF@ADP) was prepared by in‐situ polymerization with phenol‐formaldehyde (PF) resin as the wall material and halogen‐free flame‐retardant aluminum diethylphosphinate (ADP) as the core material. The effects of PF@ADP on flame retardancy and mechanical properties of LDPE were investigated by methods of combustion experiments, mechanical analysis, thermogravimetric analysis (TGA), and smoke density analysis. The results indicated that, compared with ADP/LDPE composites, the flame retardancy and mechanical properties of PF@ADP/LDPE were obviously improved. With the addition of 20 wt% PF@ADP (PF:ADP = 3:7), the limit oxygen index (LOI) of LDPE composites increased to 30.7% and UL‐94 reached V‐1 grade. The tensile strength and elongation at break reached 12.5 MPa and 431.2%, which was 20.2% and 23.1% higher than that of ADP/LDPE with the same addition. The addition of PF@ADP was beneficial to the smoke suppression of LDPE.

Tailoring the low-density polyethylene - thermoplastic starch composites using cellulose nanocrystals and compatibilizer

In this study, the mechanical, barrier, and biodegradation characteristics of low-density polyethylene (LDPE) and thermoplastic starch (TPS) composites with and without compatibilizer (CA), cellulose nanocrystal (CNCs), and their combination was investigated and compared. The results revealed the LDPE/TPS composites containing CNCs and CA exhibited higher mechanical and vapor barrier and lower water adsorption properties than LDPE/TPS composites without CA and CNCs. The combined addition of CA and CNCs resulted in homogenous composites with the highest tensile and barrier characteristics. The added CNCs led to better interaction between the LDPE and TPS phases, indicating CA could be replaced by CNCs without scarifying the performance of composites. Biodegradation investigation showed the addition of CNCs improved the resistance of LDPE/TPS composites towards biotic attacks. Improving the properties by CNCs addition could be an effective and sustainable method for reducing global utilization of LDPE in the production of LDPE/TPS composites.

UV, FIRT and surface properties of fiber reinforced low-density polyethylene laminated composites

Polymeric materials are reinforced with synthetic fibers gives as high stiffness and strength to weight ratio as compared to conventional materials. By using compression moulding technique Low Density Polyethylene composites (LDPE) reinforced with Glass, Carbon and Kevlar fiber was prepared. The resultant LDPE composites were investigated to determine the effects of fibers on their mechanical, thermal and physical properties. The tensile results illustrated that the composite reinforced with carbon fiber has the best mechanical properties as compared to other composites. This is mainly due to the proper bonding interaction between polymer matrix and the bidirectional layer of fibers. Carbon fiber has crystalline or partly crystalline structures. Composites reinforced with Glass fiber and carbon fiber has highest impact energy. Thermal properties and water absorption studies have been investigated. Study on water absorption property revealed moderate increase in weight for the composites with Kevlar fiber. Thermo gravimetric analysis (TGA) indicated retention of thermal stability of polymer composites and further characterized by FTIR & UV spectroscopy. The results clearly show that when the low-density polyethylene matrix is reinforced with fibers, morphological changes take place depending on the fiber. Supporting evidence and the surface structure was described in the form of AFM-microscopy analysis in the interfacial region of two polymer composites.

Creep and Stress Relaxation Behaviour of Rice Husk Reinforced Low Density Polyethylene Composites

The creep and stress relaxation behavior of rice husk reinforced low density polyethylene composite was analyzed in this study. The exponential and power model were used to study the creep while the stress relaxation assessed the time required for the composites to maintain a certain strain level. The creep strain increased with increase in time, at various temperatures, with its highest creep at 70oC while the lowest is at 30oC, the power model provided an excellent fit than other models with a coefficient of determination of 0.9977 at 30oC, the neat low density polyethylene had a good stress relaxation behavior with 4.95 seconds for it to decay and subsequently decreased with increase in filler concentration.

Effect of fillers on mechanical properties of recycled low density polyethylene composites under weathered condition

The study examined the effect of fillers on the mechanical properties of the recycled low density polyethylene composites under weathered condition with a view of managing the generation and disposal of plastic wastes. Discarded pure water sachets and fillers (glass and talc) were sourced and recycled. Recycled low density polyethylene (RLDPE) and preparation of RLDPE/glass, RLDPE/talc and RLDPE/glass/talc composites were carried out using a furnace at compositions of 0 – 40% in steps of 10% by weight. The mixtures were poured into hand-laid mould. The samples produced were exposed to sunlight for eight (8) weeks and their mechanical properties were studied. The results of mechanical tests revealed that tensile strength decreased with increasing filler loading while impact strength and hardness property increased marginally and considerably with increasing filler loading for all the composites respectively. The study concluded that glass and talc were able to reinforce recycled low density polyethylene under weathered condition.
 Keywords: Recycled Low Density Polyethylene (RLDPE); Fillers; Glass, Talc; Weathering condition; Sunlight; and Mechanical properties; Tensile strength, Impact and hardness

Space charge characteristics of micron- and nano-BiFeO3/LDPE composites under a magnetic field

This paper mainly studies the effects of the composites which is low-density polyethylene (LDPE) modified by BiFeO3 powder on space charge characteristics under external magnetic field treatment. In comparison, the nano-BiFeO3 powder is irregular and small when the micron-BiFeO3 powder has regular shape and overlapping structure. XRD shows that BiFeO3 powders used in materials have pure phase. According to the DSC and magnetic properties, the saturation magnetization and crystallinity of the composites under the magnetic field treatment are significantly higher than that of pure LDPE. According to the space charge test, the space charge content in the composite is lower than that in the pure LDPE, when the space charge content of nano-composites is less than that in the micron-composites, and the space charge content is lower at 1 wt% concentration. Under the magnetic field treatment, the space charge distribution of the composites can be promoted; meanwhile, the electric field distribution of the composites can be more balanced. Overall, nano-composites has the best inhibition effect on space charge accumulation, followed by class B micron-composites. The inhibition effect of class A micron-composites is worst; electric field distribution is uneven at the same time.

Investigation of Mechanical Properties of Jute Fiber Reinforced Low Density Polyethylene Composites

ABSTRACT The environmentally friendly natural fiber reinforced polymers are increasingly taking attention in several industries like automotive and construction due to their properties such as being synthesized in desired properties, easy processing, non-corrosion, low weight, and low cost. In this study, untreated/alkali-treated/silane (1.5%)-treated/alkali+ silane treated jute fabrics (25%) were reinforced to low density polyethylene (LDPE) polymer (75%) with 1%, 3%, 5% and 7% maleic anhydride additives for composite production by using hot pressing method. Further, the effect of jute fabric surface treatments on the tensile strength, flexural strength, and impact resistance properties of the LDPE/jute composites were investigated with the absence/presence of maleic anhydride additives. The results indicate that the alkali/silane treatment of jute fibers led to more than 30% improvement in mechanical properties of the composite structures when reinforced to untreated LDPE, and the mechanical properties of the composites had more than 45% improvement by maleic anhydride addition to the polymer in ideal ratios with untreated jute reinforcement.