Low-density Polyethylene Resins Research Articles

Model Simulation and Rheological Research on Crosslinking Behavior of Polyethylene Resin.

The crosslinking behavior of polyethylene (PE) determines its exceptional performance and application. In this study, we investigated the crosslinking behaviors of different PE resins through model simulation and rheological methods. Specifically, the mathematical equation of "S" model was established for PE resin. According to this equation, the optimal maximum gel content for high-density polyethylene (HDPE) was found to be around 85%. Moreover, the maximum crosslinking degrees for different PE resins depended largely on their density and molecular weight. The melt viscosities before crosslinking in PE resins were highly influenced by their melt index. The higher melt indexes resulted in the lower storage moduli, improving melt processability during processing. In addition, the crosslinking rates of PE resins were strongly influenced by peroxide concentration, independent of PE resin structures. For high molecular weight and low-density PE resins, they exhibited decreased ti values, increased A0 values, and decreased k6 values. However, there were no noticeable variations in the values of k2 and phi among different PE resins. All simulated modeling outcomes showed remarkable consistency with the experimental rheological data. These findings are of strong significance in the industrial manufacture of PE resin.

Mechanical properties of rCB-pigment masterbatch in rLDPE: The effect of processing aids and water absorption test

Abstract Homogenization of pigment is the key to coloring a plastic product evenly. In this article, the tensile properties of recovered carbon black merge with low molecular weight lubricants and other compounding ingredients in the form of pigment masterbatch (PM) added in a recycled low-density polyethylene (rLDPE) resin were evaluated. The prepared masterbatch with the varying amount and types of processing aids (A and B) was first compounded using the heated two-roll mill. Subsequently, the manually mixed masterbatch in rLDPE was put through an injection molding machine for the shaping process to produce an rLDPE pigment masterbatch composite (PMC). The tensile test was performed on the samples to evaluate the mechanical properties of the PMC. Meanwhile, the melt flow index test was executed to justify the composite flow characteristics. Fourier-transform infrared spectroscopy analysis and scanning electron microscopy were also carried out to analyze the PM and PMC chemical properties and their constructed surface morphology. Besides, X-ray diffraction analysis was performed to determine the changes in degree of crystallinity before and after the water absorption test. The addition of PM in rLDPE has slightly increased the rLDPE matrix tensile properties. While, the usage of more processing aid B in the PMC has turned out to secure better tensile properties compared to the addition of higher amount of processing aid A in the PMC. Interestingly, the tensile properties of all composites after the water absorption test were enhanced, suggesting that a stronger bond was formed during the immersion period.

Tuning tear and slow crack growth resistance of linear low-density polyethylene resins through partial replacement of 1-butene with 1-hexene

The present study encompasses the utilization of a mixture of 1-butene and 1-hexene comonomers for the large-scale production of a film-grade linear low-density polyethylene (LLDPE) resin. The goal involves assessing the impact stemming from the partial replacement of 1-butene with 1-hexene on the thermal, physical, mechanical and rheological properties of the resultant resin, juxtaposed against an LLDPE counterpart exclusively produced by 1-butene as the comonomer. Although the comprehensive examination of key physical, thermal, rheological and mechanical characteristics indicates nominal influence due to the substitution, a marked escalation materializes in both the tear resistance and slow crack growth (SCG) resilience of the LLDPE resins formulated through the amalgamation of these comonomers. Specifically, the tear and SCG resistance of the proposed resin exhibit an extraordinary surge exceeding 60% and 30%, respectively. This discernible enhancement underscores the viability of the proposed technique as a propitious avenue for augmenting the requisite mechanical properties, obviating the need for an all-encompassing shift from 1-butene to longer-chain α-olefin comonomers.

Performance comparison of semi‐conductive shielding layer for high‐voltage cable based on polypropylene and low density polyethylene resin

AbstractWith the concept of environmental protection is deeply popular, the power cables change from traditional thermosetting cross‐linked polyethylene (XLPE) cables to low‐carbon, environmentally friendly, recyclable polypropylene (PP) cables and the semi‐conductive shielding layer that matches the insulation layer for PP cables is highly valued. In this paper, LDPE is replaced with PP in the formulation of shielding layer of commercial XLPE cables. The physicochemical and electrical properties of PP/EVA/CB (PP‐based) and LDPE/EVA/CB (LDPE‐based) shielding layers were compared. The effect of interface matching characteristics on the electric field distortion was analyzed by finite element simulation software. The experimental results show that the volume resistivity of the shielding layers all tend to rise with the increasing temperature, but the resistivity of the PP‐based shielding layer has a smaller fluctuation. The PP‐based shielding layer has a smoother surface, while the space charge injected into the PP insulation layer is the lowest, about 0.433 × 10−7 C. Compared to the LDPE‐based shielding layer/insulation layer, the PP‐based shielding layer/insulation layer has a 50% reduction in interfacial electric field distortion rate. This work is an essential reference for the development for PP cables and their shielding layer selection.

Investigating the thermal and mechanical properties of novel LDPE/TiO2 and LDPE/TiO2/CNT composites for 3D printing applications.

The development of new materials is essential for advancing technology and improving the quality of life. With new materials, we can create products that are stronger, more durable, and more efficient. The ongoing research and development of new materials for 3D printing applications continue to drive innovation in various fields, leading to improved products and processes with great benefits. The main goal of this work was to produce a functional filament with a 1.75-mm diameter that may be used for 3D printing. Composite materials were prepared using a low-density polyethylene (LDPE) resin as polymer matrix, and titanium dioxide (TiO2) and carbon nanotubes (CNT) as fillers in various ratios. Up to 15 wt% of TiO2 and 0.25 wt% of CNT were added. Some of the greatest difficulties with high filler content composites are achieving good homogeneity, and in the case of the 3D printing, greatest difficulties are producing the filament with a specific and stable filament diameter. During the 3D printing itself, the fillers can also often cause the nozzle clogging. This paper reports findings of thermal and mechanical properties of the LDPE/TiO2/CNT composites which are significant for the 3D printing process and the applicability of the composite materials. All of the planed composite materials are successfully prepared and 3D printed into the tensile test specimens. The melting point shift caused by the addition of fillers did not show consistent pattern at differential scanning calorimetry, as all of the samples had melting temperatures around 113.5 ± 1.4 °C. The addition of filler, according to the TGA, increased the threshold temperature for the material decomposition, in case of TiO2 5.4 °C increase, while TiO2 and CNT combination increased the threshold temperature for 6.8 °C. The results of the tensile test show a general increase trend with addition of TiO2 filler but do not show to a trend for the tensile strength as a result of the addition of CNT filler. The sample with highest TiO2 filler ratio of 15% (LDPE 15T0C) showed the greatest tensile strength of 14.5 MPa, compared to the 13.0 MPa of pure LDPE. The sample with 5% of TiO2 filler and 0.1% of CNT filler (LDPE 5T0.1C) showed the greatest elongation of 73.9%, compared to the 68.9% of pure LDPE.

Titanium dioxide microspheres modified with cobalt stearate as a photocatalyst for the degradation of polyethylene films

The degradation of plastics is of great importance due to the ever-increasing concerns of environmental issues. Herein, we report a photocatalyst for the degradation of polyethylene (PE) films, that is, nano titanium dioxide (TiO2) nanoparticles modified with cobalt stearate, which was prepared by sol-gel method and surface modification. Its structure, morphology, and thermal stability were studied by powder X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Then the prepared photocatalyst was added to the linear low-density polyethylene (LLDPE) resin, resulting in a novel PE/TiO2 composite film. The effects of the modified TiO2 on the plasticity of PE film and the degradation performance of the composite film under UV irradiation were investigated. The mechanical properties, molecular weight change, and melting index (MFR) of the film were measured. The results revealed that the degradation properties of PE films were significantly improved after the addition of modified nano TiO2 microspheres. Under UV irradiation for 96 h, the tensile elongation retention rate of the composite film dropped to 0. The peak at 1713 cm-1 attributable to the stretching vibration of CO in infrared spectra significantly increased and the weight-average molecular weight (Mw) of the film decreased from 1.2 × 105 g mol-1 to 0.85 × 104 g mol-1. The melt flow rate was enhanced to 194.2 g/10 min. These results suggest that the present modified TiO2 could be utilized as a promising photocatalyst candidate for the degradation of plastics.

Synthesis of silylamine and siloxyamine compounds: A novel approach to flame retardancy of polypropylene and Epoxy resins

A series of innovative flame retardants containing N-Si and N-O-Si bonds have been synthesized. Their chemical structures were verified by nuclear magnetic resonance (NMR) spectroscopy and thermal stabilities determined by thermogravimetric analysis (TGA). The results indicate that their thermal and hydrolytic stabilities could be adjusted by fine tuning their silylamine (N-Si) and siloxyamine (N-O-Si) skeletons. Thus, the substituents bonded to the phthalimides, such as diphenylmethylsilyl, dimethylphenylsilyl, diphenyl‑tert-butylsilyl, triisopropylsilyl or diphenylmethylsiloxy; whichever was attached to the imide played a significant role on its thermal and hydrolytic properties. Upon thermal dissociation, the N-Si and N-O-Si compounds were shown to yield aminyl, silyl and oxygen-centered radicals that provided fire proofing effect in polypropylene (PP) films alone and a synergistic effect in combination with conventional phosphorous flame retardant in PP, linear low-density polyethylene (LLDPE) and epoxy resins (EP). Their efficacy as flame retardants alone in thin PP films were evaluated according to the DIN4102-B2 test. Both N-Si and N-O-Si significantly slowed down the burning of PP films. Moreover, their potential as adjuvants with a conventional phosphorous based flame retardant, i.e., spirocyclic phosphonate (AFLAMMIT® PCO 900) in PP and EP resins was evaluated according to the UL-94 V fire standard. A synergistic effect was observed when the phosphorous flame retardant was combined with either N-Si or N-O-SI containing compounds, since none of the flame retardants by themselves could provide V-0 rating in the UL94-V test in PP, LLDPE or EP resins even at much higher loadings. The thermogravimetric analysis carried out under inert atmosphere revealed enhanced and earlier onset of decomposition and thermal activation of phosphorous based flame retardant in the presence of N-Si or N-O-Si in comparison to spirocyclic phosphonate, N-Si or N-O-Si used alone, respectively. The interaction of the phosphorus flame retardant with N-Si was verified by 31P NMR.

A rheology and processing study on controlling material and process defects in polymer melt extrusion film casting using polymer blends

The primary objective of this research paper is to control the material and process defects in polymer melt extrusion film casting (EFC) process for linear chain architecture polyethylene (PE) resins through polymer blending methodology. Extrusion film casting is a well-known industrially important manufacturing process that is used to manufacture thousands of tons of polymer/plastic films/sheets and coated products. In this research, the necking defect in an EFC process has been studied experimentally for a linear low density polyethylene (LLDPE) resin and attempts have been made to control its necking by blending in a long chain branched (LCB) low density polyethylene (LDPE) resin. The blending methodology is based on the understanding that a LDPE resin displays enhanced resistance to necking as compared to the LLDPE resin. It is found that added LDPE resin enhances necking resistance for the primary LLDPE resin. Further, as the LDPE concentration increases in the blend formulation, the necking is further reduced as compared to pure LLDPE. Analogous to past studies on EFC of linear and long chain branched architecture containing PEs, it is observed that as the LDPE is increased in the blend formulations, the formulations displayed enhanced melt elasticity and extensional strain hardening in rheological studies. It is concluded from this study that polyethylene resins having linear chain architecture can be made amenable to enhanced resistance to necking using appropriate amount of a long chain branched resins. Finally, process defects such as the draw resonance onset could be shifted to higher draw ratios as the LDPE level is increased in the LLDPE-LDPE blend formulation.

Overview of Polyethylene Based Multi-layered Geomembrane Through Blown Extrusion Process

Geomembranes are low-permeable liners used to control the molecular migration in many proven applications. Landfills is most common application in the field of civil and environmental engineering. Geomembrane is the main component in lining system which works as hydraulic barrier. The polyolefins are the basic materials of liner and more commonly polypropylene and polyethylene are preferred. Commercial manufacturing process involves extrusion techniques viz cast extrusion and blown extrusion process. The individual process is designed for multiple layered structures which are then coextruded to lead into a single liner. Typical structure comprises, high to low-density polyethylene (PE) resin, processing aids, stabilisers to retard the degradation through ultra-violet rays, photo-oxidation, and thermal oxidation. The stabilizer is usually used in smaller dosses to avoid degradations which includes, 2 to 3% carbon-black (CB), 0.5 to 1% antioxidants (AO), and plasticizing additives to introduce the flexibility. During the process, components are homogenised in specially designed screws of feeding and mixing zones. The formulated melt is co-extruded through specially designed die of multi-layered structures. The subsequent melt enters in circular die with a certain pressure which leads to bubbled shaped films. The variation in the surface morphology layer structure and layer number are the important technical aspects to alter the required end application. Finally, manufactured geomembrane is qualified as per the international specifications which are governed by geosynthetic research institute (GSI/GRI).

Comparison of permeabilities of eight different types of cytotoxic drugs to five gloves with different materials by LC-MS/MS methods to reduce occupational exposure of medical personnel.

Occupational exposure is a long-standing public health concern, which has drawn more and more attention in recent years to the problem of how to carry out occupational protection effectively. Gloves are regarded as the most critical protective equipment for cytotoxic medications. However, there is still little research conducted on the protective performance of gloves made of different materials and the optimal glove combination for cytotoxic agents. In this research, a specific instrument intended for glove permeation experiment was designed, with various methods of liquid chromatography-tandem mass spectrometry (LC-MS/MS) developed and validated. By using the specific instrument and LC-MS/MS methods, a study was conducted on the permeation ability of eight selected cytotoxic drugs (fluorouracil, epirubicin (EPI), docetaxel (DCT), methotrexate (MTX), cyclophosphamide (CTX), etoposide (ETP), vincristine sulfate (VCR), and cisplatin derivatives Pt-(DDTC)3) into five kinds of gloves (rubber (RB), nitrile (NT), chlorinated polyethylene (CPE), low-density polyethylene, and polyvinylchloride (PVC) resin) given different contact times. Then, the experimental data were analyzed through a generalized estimation equation and Pearson correlation analysis. The results show that within a short period of time (less than five minutes), ETP, CTX, fluorouracil, DCT, and cisplatin passed through five types of gloves but the level of MTX, VCR, and EPI permeation was minimal, despite the duration of contact between the three drugs and the gloves reaching as long as three hours. Furthermore, the permeation of DCT and ETP was found to be positively correlated with time. Chlorinated polyethylene and PVC resin perform well in protecting against most cytotoxic drugs and are recommendable for clinical practice. Due to the poor protective ability, RB gloves are not recommended for this purpose. Based on the performance of various gloves in offering protection, the protection grade of two gloves can be deduced. Chlorinated polyethylene + PVC resin, CPE + NT glove combination shows good protective performance against most target drugs and can be recommended for clinical practice.

Analytical characterization of erucamide degradants by mass spectrometry

Polyolefins use erucamide as one of their primary slip agents. The degradation of erucamide can occur during polymer processing and long-term storage, leading to the formation of numerous oxidation products. Erucamide degradation produces compounds that adversely affect the odor and color properties of polyolefins. The article describes the comprehensive characterization of erucamide degradation products formed in three different lots of low-density polyethylene (LDPE) using thermal desorption-gas chromatography mass spectrometry (TD-GC/MS) and liquid chromatography-high resolution mass spectrometry (LCHRMS) techniques. More than 20 volatile and non-volatile degradation compounds of erucamide were identified in LDPE. The structures of non-volatile degradants were predicted using both the molecular formula generated and MS/MS fragmentation data obtained by LCHRMS. The non-volatile and volatile degradation compounds formed in odorous LDPE resins were compared with that of the reference sample of LDPE having no odor. Further, the plausible mechanism of formation of volatile and non-volatile degradation compounds of erucamide is proposed.

Organosolv Lignin Improved Thermoplastic Elastomeric Behavior of Polyethylene/Polyisoprene Blend.

Thermoplastic elastomers are considered the fastest-growing elastomers in recent years because of their thermomechanical recyclability, in contrast to traditional thermoset rubbers. Polyolefins such as low-density polyethylene (LDPE) show low mechanical properties, particularly poor elongation when compared with an elastomer or rubber. In this study, LDPE resin is converted to highly ductile rubber-like materials with high elongation and low modulus properties on blending with polyisoprene rubber (IR), followed by treating with dicumyl peroxide as a curing agent and organosolv lignin as an additive. The technique of high shear melt-mixing, in conjunction with vulcanization or crosslinking using organic peroxide, is used to develop hybrid materials based on the LDPE/IR blend at a 70/30 mass ratio, where LDPE is replaced partly with lignin. Various characteristics such as tensile, viscoelasticity, melt flow, crystallinity, and phase morphology of the materials are analyzed. As expected, vulcanization with peroxide can improve the mechanical performance of the LDPE/IR blends, which is further improved with the application of lignin (2 to 5 wt. %), particularly tensile strain is profoundly increased. For example, the average values of the tensile strength, the modulus, and the ultimate elongation of neat LDPE resin are 7.8 MPa, 177 MPa, and 62%, respectively, and those of LDPE/IR/lignin/DCP 65/30/05/2 are 8.1 MPa, 95 MPa, and 238%, respectively. It indicates that the application of lignin/DCP has a profound effect on improving the ductility and elastomeric characteristics of the materials; thus, this material can have the potential to replace traditional rubber products.

Recycled polyethylene/polycarbonate blends compatibilized with oxidized polyethylene/CaCO3

AbstractPolyethylene (PE) and polycarbonate (PC) are not thermodynamically miscible, and they tend to be phase‐separated during melt‐processing, because of significant incompatibility in structures and properties. Interestingly, minerals such as CaCO3 are used in PE‐based supermarket bags for improving surface characteristics. In this study, recycled low‐density polyethylene (LDPE) and PC resins are melt‐blended at 50/50 wt%, without and with oxidized polyethylene (OPE) as a compatibilizer. A parallel experiment is conducted with 50/50 blends of virgin LDPE and PC resins. Various characteristics such as tensile, viscoelastic, melt‐flow, and phase morphology of the materials are analyzed. The 50/50 blend of recycled LDPE/PC blend shows an average tensile strength of 15 MPa, which increases to 24 MPa on the addition of 5 wt% OPE, where total recycled content is 95 wt% including 15 wt% CaCO3. Notably, the presence of CaCO3‐based filler in recycled LDPE has a profound effect in improving the mechanical performance of the materials.

Antimicrobial ceramic hybrid films for keep-freshness packaging with fluorinated illite particles

This work reports the preparation of a ceramic hybrid film for keep-freshness with enhanced oxygen and moisture permeability, and antimicrobial properties using fluorine-coated illite (F-illite) and low-density polyethylene (LDPE) resin. Before the film was manufactured, a master batch of F-illite and LDPE was prepared through an extruder, and a large amount of LDPE resin was mixed to produce a film containing 4wt% F-illite. The amount and dispersity of the F-illite in the LDPE matrix were confirmed by TGA, wide-angle XRD and SEM analysis. As a result, the F-illite hybrid films had an oxygen transmission rate (OTR) of 13,430 mL/m2۰day), which is higher than 10,309 mL/m2۰day of the general LDPE film. Moreover, the water vapor transmission rate (WVTR) was 20.13 g/m2, which was higher than that of the general LDPE film 16.13 g/m2·day. In addition, the F-illite hybrid film showed more than 99% antibacterial activity against S. aureus.

Modifikasi Polietilen sebagai komposit Plastik Polimer Biodegradable dengan Filler Tepung Kulit Pisang Talas

Synthetic polymer polyethylene LDPE has been grafted with natural polymers of banana talas (Musa paradisiacal Var sapientum L.) peels flour. The aim of this research is to make compossed plastic of the thermoplastic banana peels flour with LDPE resins plastic based on mechanic and degradation behaviours. Low Density Polyethylene (LDPE) resins, glycerol, banana peels, humus soil, xylene p.a as the raw materials. Thermoplastic banana peels flour produced by added 30% glycerol concentration and then by aging for 2 weeks. The mixing of the thermoplastic banana peels flour with LDPE resins using a ratio of 1:3, 2:3 and 3:3. Xylene (coupling agent) 6 times of the total mass were added to increase compatibility between thermoplastic banana peels flour and LDPE. The mechanical properties of composite were analyzed using ASTM D638 method and the biodegradation capability composite were charactherized using soil burial test method. The results show that tensile strength in the ratio of 1:3, 2:3, 3:3 respectively were 28.94 kg/cm2, 36.16 kg/cm2, 29.94 kg/cm2. The percentage of residual weight show the biodegradation capability in the ratio of 1:3, 2:3, 3:3 was 98.46%, 97.67%, 98.24%. Mixing ratio of 2:3 thermoplastic banana peels flour and LDPE has the best value of tensile strength and degradation capability. Mixing ratio of 2:3 thermoplastic banana peels flour and LDPE has the best value of tensile strength and degradation capability.

Structural Model for the Estimation of the Equivalent Permittivity of Nanodielectrics Based on Polyethylene and Epoxy Resins

A structural model for the calculation of the equivalent permittivity of nanocomposites based on low-density polyethylene (LDPE) and epoxy resins (ERs) with inorganic fillers was developed. It was assumed that each nanoparticle was centered in an interfacial region composed of three layers in the case of LDPE-based nanocomposites, and of two layers in the case of ER-based nanocomposites. The model for the estimation of the permittivity was designed for flat samples of the height $g$ , divided into cubes with the side-length $l$ . Each of these cubes contains eight nanoparticles, which are separated from the polymer matrix by two or three layers. Based on the types and concentrations of dipoles present in the layers, the relative permittivity of each layer of the interface can be calculated. By the employment of a 3D numerical model in COMSOL, implemented by the finite element method associated with a cube, the distribution of the electric field inside a cube can be determined, which yields the values of the equivalent permittivity of the nanocomposites. In order to verify the numerical results, the permittivity of the nanocomposites based on LDPE and ERs with inorganic nanofillers (SiO2 or Al2O3) was determined in laboratory experiments. The results reveal congruent correlation between the computed and the experimentally determined values of the equivalent permittivity of the nanodielectrics.

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.

Dow resin has recycled content

Dow is introducing a low-density polyethylene resin that contains 70% recycled content. The resin can be blended with virgin polyethylene to create shrink films—the kind that hold cases of water bottles together—with up to 40% recycled content. Dow sources the recycled material from Avangard Innovative, which recycles polyethylene film in Houston.

A Method of Large-Scale Resource Utilization of Algae—Eutrophic Waste from Lake Chao, China: Preparation and Performance Optimization of Composite Packaging Materials

In order to realize the resource utilization of bloom algae from Lake Chao, this study presents the use of fresh algae to improve the mechanical and biological properties of low-density polyethylene (LDPE). In this study, the algae and LDPE were used as raw materials, maleic anhydride grafted polyethylene (PE-g-MAH), polyethylene wax (PE-wax) and white oil, and glycerin were used as the compatibilizer, lubricant, and plasticizer, respectively. The single factor experiments were conducted with these three individual factors, and the response surface methodology technique was used to optimize the process conditions. In the single factor experiments, the mechanical properties of the composites increased with additions of PE-g-MAH, PE-wax/white oil, and glycerin. Both flexural strength and flexural modulus were maximized to optimize the preparation conditions. The optimum preparation conditions were found as follows: algae powder of 15.00 wt%, LDPE of 85.00 wt%, PE-g-MAH of 4.00 wt%, lubricant of 2.67 wt%, and glycerin of 3.00 wt%. This resulted in 11.60 MPa of tensile strength, 9.95 MPa of flexural strength, and 241.00 MPa of flexural modulus. The mechanical properties of composites were greatly improved compared with the absence of additives. In addition, compared with LDPE resin, the degradability of the composite was improved, and the weight loss rate was 7.73% after 6 months. The results recommended that the composites of the algae from Lake Chao and LDPE resin could be a useful material in the packaging field. Generally, the prepared composite particles can be used to produce foam products, packaging bags, or hard packing boxes with special shapes. It is more environmentally friendly, and more able to meet the challenges of sustainable development.