Mixture Of Polyethylene Research Articles

Mechanical and Tribotechnical Characteristics of Nanocomposites Based on Mixture of Ultrahigh Molecular Weight Polyethylene and Polypropylene

The aim of the study is to design wear-resistant and extrudable polymeric composites based on mixture of UHMWPE+PP with increased tribotechnical characteristics for the wide application in friction units of machine parts and mechanisms as well as using the polymeric resin developed for obtaining nanocomposites. Adding of block copolymer PP-b LLDPE to UHMWPE is motivated by the necessity to increase the adhesion between the incompatible polymeric components of the mixture. It is shown that wear intensity of the polymer-polymeric composites UHMWPE+n wt.% PP-b-LLDPE is reduced at filling UHMWPE by the block copolymer. In doing so, an important technological characteristic of UHMWPE specific extrusion pressure (proportional to the melt flow index) is improved (is lowered). Nanocomposites on the basis of the given matrix have shown wear resistance of 3-4 times higher in contrast with pure UHMWPE. Permolecular structure and wear track surfaces of nanocomposites on the basis of polymer-polymeric matrix (UHMWPE+10 wt.% PP-b-LLDPE) were investigated. The mechanism of the wear of nanocomposites is discussed.

Ingested plastic transfers hazardous chemicals to fish and induces hepatic stress

Plastic debris litters aquatic habitats globally, the majority of which is microscopic (< 1 mm), and is ingested by a large range of species. Risks associated with such small fragments come from the material itself and from chemical pollutants that sorb to it from surrounding water. Hazards associated with the complex mixture of plastic and accumulated pollutants are largely unknown. Here, we show that fish, exposed to a mixture of polyethylene with chemical pollutants sorbed from the marine environment, bioaccumulate these chemical pollutants and suffer liver toxicity and pathology. Fish fed virgin polyethylene fragments also show signs of stress, although less severe than fish fed marine polyethylene fragments. We provide baseline information regarding the bioaccumulation of chemicals and associated health effects from plastic ingestion in fish and demonstrate that future assessments should consider the complex mixture of the plastic material and their associated chemical pollutants.

Water Absorbency and Mechanical Properties of Kenaf Paper Blended via a Disintegration Technique

In this study, blended paper was prepared by blending synthetic polyethylene (PE) via a disintegration technique. The produced paper was targeted to resist water or moisture. Unbleached kenaf whole stem pulp was used as the main source of fibre in making the paper. The pulp was blended with two types of PE: low-branched (LB) and high-branched (HB) polymers. To study the effect of PE addition to the paper, the water absorbency and mechanical properties were characterized. The pulp to PE mixtures were prepared at ratios of 9:1, 8:2, 7:3, 6:4, and 5:5. Scanning electron microscopy (SEM) showed that the PE was melted between the fibre linkages. The Cobb test determined that the blended paper absorbed less than 20 g/m2 of water within 60 s. The best water contact angle successfully achieved was at 84°, which is almost hydrophobic. The mechanical properties, such as tensile strength and tear strength, were in the range of accepted standard requirements. The obtained results indicated that blending via a disintegration technique can be applied in the process of making water-resistant paper. The produced paper is suitable for the manufacturing of water-resistant corrugated packaging materials.

Monometallic nickel(II) complexes containing N,N′-iminopyridine chelating ligands with dendritic substituents: The influence of dendrimer topology on the catalytic oligomerization and polymerization of ethylene

Iminopyridine ligands of general formula Gn-PBE-ONN (Gn-PBE=Fréchet-type dendritic wedges of generation G0 (1), G1 (2), G2 (3), and G3 (4); –ONN=-O-4-(2,5-Me2C6H2)-NCH-2-py) have been prepared starting from H-ONN. Reaction of these bidentate ligands with [NiBr2(DME)] results in the nickel(II) complexes [NiBr2(Gn-PBE-ONN)] (5–8). The methylaluminoxane (MAO)-activated monometallic complexes have been studied in the transformation of ethylene into mixtures of polyethylene and oily oligomers, and their catalytic performance scrutinized as a function of dendritic size. A comparison with the behavior observed for related polymetallic dendrimers has enabled the dendritic features that affect various catalytic parameters to be determined. Thus, it has been possible to discern whether the dendritic effect detected in the catalysis should be ascribed to the metallic nuclearity rather than the bulkiness of the metallodendrimer.

Burning of thermally thin polyethylene mixtures

The burning of polyethylene in the mixture with aluminium hydroxide, aluminium oxide, cellulose and Irganox 1010 has been examined by cone calorimeter under non-standard sizes of the sample. The time to ignition of pure polyethylene decreases with decreasing initial amount of polyethylene powder. The subtraction of the mass of water released from the total mass lost for polyethylene with aluminium hydroxide give the same values of effective heats of combustion as for pure polyethylene up to the load about 50 mass% of aluminium hydroxide. The mean heats of combustion determined from the cone calorimeter software are higher than those determined from the total oxygen consumed and mass lost multiplied by the factor 13.1. The additivity rule was found for effective heat of combustion and total smoke released for polyethylene with cellulose. The free radical scavenger Irganox 1010 does not show a significant effect on the flammability of polyethylene except for the increase of the total smoke released. The equation describing the heat release rate evolution in time has been proposed showing a good fit to the experimental runs.

Analysis of conical spouted bed fluid dynamics using carton mixtures

The pyrolysis has risen as an important alternative technology for generating value from waste. Among the modern solid wastes, the post-consumer carton packaging highlights due to the high value-added of the primary products obtained from pyrolysis. In an attempt to use conical spouted beds (CSBs) as a pyrolysis reactor for processing cartons, this present research aims at analyzing experimentally the air–carton mixtures flow dynamics in CSBs and stating comparisons with characteristic fluid dynamics obtained by using CFD technique. The flow behavior of air–carton disk is experimentally investigated by analyzing data of bed pressure drop, air velocity and fountain height. For the carton disk and polyethylene mixtures up to 50% cartons (in mass), and carton disks and sand mixtures comprising 5 and 10% cartons (in mass), the analysis of the experimental data shows that the stable spouted regimes are achieved. Furthermore, the simulated results demonstrate that the Eulerian approach using the Syamlal drag model is able to predict qualitatively the flow behavior in conical spouted beds comprising non-spherical particle mixtures.

A Degradation Kinetic Study on Pyrolysis of Three Biomass Samples and Co-pyrolysis of Hazelnut Shell and Ultra-high Molecular Weight Polyethylene Blends Using a Silver Indicator

A kinetic study was proposed in pyrolysis process supplementary to thermo-gravimetric analysis. Three different biomasses, hazelnut shell, olive residue, and tea waste, and hazelnut shell and ultra-high molecular weight polyethylene mixture were analyzed kinetically in a batch-type tubular pyrolysis reactor. Reaction times were measured with the changing color of silver indicator, which was attached to the terminal of pyrolysis set up at various specified temperatures between 623 and 923 K. The Arrhenius plots were obtained and the activation energies (Ea ) of reaction values were calculated from the slope of linear curves. For pure biomass, two linear degradation zones were detected possibly belonging to cellulose and hemicellulose. In the case of hazelnut shell and ultra-high molecular weight polyethylene mixtures, linearity of Arrhenius plots were grasped with the modification of the pre-exponential factor of the basic Arrhenius equation. This type of kinetic method directly involves the basic parameters, namely, reaction time and temperature for supplementation of kinetic analysis.

Conversion of low density polyethylene into fuel through co-processing with vacuum gas oil in a fluid catalytic cracking riser reactor

In this work, mixtures of vacuum gas oil and low density polyethylene, a major component of common industrial and consumer household plastics, were pyrolytically co-processed in a fluid catalytic cracking (FCC) riser reactor as a viable alternative for the energy and petrochemical revalorisation of plastic wastes into valuable petrochemical feedstocks and fuel within an existing industrial technology. Using equilibrium FCC catalyst, the oil–polymer blends were catalytically cracked at different processing conditions of temperatures between 773K and 973K and catalyst feed ratios of 5:1, 7:1 and 10:1. The influence of each of these processing parameters on the cracking gas and liquid yield patterns were studied and presented. Further analysed and presented are the different compositional distributions of the obtained liquids and gaseous products. The analysis of the results obtained revealed that with very little modifications to existing process superstructure, yields and compositional distributions of products from the fluid catalytic cracking of the oil–polymer blend in many cases were very similar to those of the processed oil feedstock, bringing to manifest the viability of the feedstock co-processing without significant detriments to FCC product yields and quality.

Synthesis and Structural Analysis of (Imido)Vanadium(V) Complexes Containing Chelate (Anilido)Methyl-imine Ligands: Ligand Effect in Ethylene Dimerization

A series of (imido)vanadium dichlorido complexes containing chelate anionic donor ligands of the type, VCl2(L)(NR) [R = 1-adamantyl (Ad), L = 2-(2,6-Me2C6H3)NCH2(C9H6N) (2), 8-(2,6-Me2C6H3)NCH2(C9H6N) (3); L = 2-(2,6-R'2C6H3)NCH2(C5H4N), R = 2-MeC6H4, R' = Me (4a), (i)Pr (4b); L = 2-(2,6-Me2C6H3)NCH2(C5H4N), R = 4-MeC6H4 (5), 3,5-Me2C6H3 (6)], have been prepared and identified. The reactions with ethylene by 2,3 in the presence of methylaluminoxane (MAO) afforded a mixture of high molecular weight polyethylene and oligomers. Reactions with ethylene by VCl2[2-(2,6-R'2C6H3)NCH2(C5H4N)](NAd) (1a,b), 4-6 afforded 1-butene with high selectivities (>92%), and the activities by 4a,b are at the same level as those in 1a,b. The activities by 5,6 were lower than 4a,b and were at the same level of that by VCl2[2-(2,6-Me2C6H3)NCH2(C5H4N)](NPh). These results thus suggest that both the chelate anionic donor and the imido ligands play a role for both the activity and the selectivity.

The Mechanical Properties of a Mixture of High Density Polyethylene and Calcium Carbonate Dedicated for Packaging

Packaging made of polymeric materials is one of the most important branches of polymer processing. A very essential task which is to be solved in this area, is searching for new materials which would allow for lowering the cost while still maintaining good mechanical properties. In the current paper the attempt to decrease the cost of the HDPE intended for blow moulding of packaging by admixing CaCO3 filler is presented. The dependence of mechanical properties upon the filler content is also shown.

PLS model investigation of thiabendazole based on THz spectrum

THz spectrum of thiabendazole was determined with terahertz time domain spectroscopy (THz-TDS) at room temperature, and comparison of its THz spectrum with other two bactericides (thiophanate-methyl and benomyl) was given. The solid-state density functional and isolated-molecule theories were employed to interpret thiabendazole's THz spectrum with the PW91 density function and d and p polarization (DNP) basis set. In addition, we applied THz-TDS to detect mixtures of thiabendazole and polyethylene with different ratios, and compared the performances of four variable selection methods for the prediction of thiabendazole content. The tested variable selection algorithms included partial least squares (PLS), interval PLS (iPLS), backward iPLS (biPLS) and moving window PLS (mwPLS). The PLS model intervals were optimized according to the root mean square error of cross validation (RMSECV) in the calibration set. The performances of models were evaluated according to the root mean square error of prediction (RMSEP), correlation coefficient (R) and relative error (E) in the prediction set. In contrast with the other three methods, the mwPLS yielded the most accurate result. The optimal mwPLS model was obtained with RMSEP=0.3629, R=0.9995 and E=3.75%, and the investigation of mwPLS models with various window sizes from 3 to 71 were examined.

Effect of Wood Biomass Addition on the Char Making Process of Waste Plastic for Controlling the Combustion Efficiency

AbstractAfter Kyoto protocol, many companies and institutions in the industrialized countries focused on the energy saving and the utilization of waste heat and materials widely for reducing the CO2 emission. In such a circumstance, it is key technology for reducing CO2 emission by using the waste materials efficiently such as a plastic and wood biomass.In this paper, a method for improving the reactivity of plastic char using wood biomass was investigated. The XRD analysis was performed for elucidating the carbon structure change by addition of wood to PE (polyethylene) and reactivity test with O2 gas was carried out to clarify the reaction rates of the mixtures of PE and wood.It was found that the crystallization degree of char decreased continuously with the addition of wood to polyethylene, which meant that the reactivity of polyethylene char increased.

Dust explosion risk moderation for flocculent dusts

The research presented in this paper is focused on dust explosions of coarse and fine flocculent (or fibrous) samples of wood and polyethylene. Hybrid mixtures of fibrous polyethylene and admixed ethylene were also studied. Experimentation was conducted by following standardized test procedures and using standardized apparatus for determination of maximum explosion pressure, size-normalized maximum rate of pressure rise, minimum explosible concentration, minimum ignition energy, and minimum ignition temperature. A general trend was observed of enhanced explosion likelihood and consequence severity with a decrease in material diameter, as well as enhanced consequence severity with admixture of a flammable gas to the combustion atmosphere. The same phenomena are well-established for dusts composed of spherical particles; this highlights the importance of inherently safer design and the principle of moderation in avoiding the generation of fine sizes of flocculent dusts and hybrid mixtures of such materials with flammable gases.In addition to presenting experimental findings, the paper describes phenomenological modelling efforts for the flocculent polyethylene using four geometric equivalence models: radial equivalence, volumetric equivalence, surface area equivalence, and specific surface area equivalence. The surface area equivalence model was found to yield the best estimates of maximum rate of pressure rise for the flocculent polyethylene samples investigated experimentally.

Sorption of remazol brilliant blue R onto polyurethane‐type foam prepared from peanut shell

AbstractThe powders of peanut shell is first liquefied with the mixture of polyethylene glycol‐400 and monoethylene glycol (MEG) using sulfuric acid at 160°C for 2 h. Polyurethane (PU)‐type rigid foam is prepared from the reaction between peanut shell liquefied with the MEG and diphenylmethane diisocyanate. Then the PU foam is used as a sorbent for the removal of the remazol brilliant blue R from aqueous solution. The sorption of the dye increases with increasing initial concentration, temperature, and ionic strength, while decreasing with increasing pH. From the isotherm and kinetic studies, it is seen that the sorption process is in the best agreement with the Langmuir isotherm and the pseudo second‐order kinetic model. Desorption and FTIR studies show that a chemisorption process occurs between dye and foam, probably indicating electrostatic interactions. The thermodynamic parameters (i.e., standard free energy, standard enthalpy, and standard entropy) are determined, and the results obtained are discussed in detail. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci, 2013

Catalytic stepwise pyrolysis of packaging plastic waste

In this paper the combination of catalytic and stepwise pyrolysis is explored. A mixture of polyethylene (PE), polypropylene (PP), polystyrene (PS), poly(ethylene terephthalate) (PET) and poly(vinyl chloride) (PVC), which resembles real municipal plastic waste, has been pyrolysed in a 3.5dm3 semi-batch reactor at 440°C for 30min using a ZSM-5 zeolite as catalyst. A low temperature (300°C) dechlorination step has been carried out both with and without catalyst. It has been proved that the application of such dechlorination step gives rise to a 75wt% reduction of chlorine in the liquid fraction. However, such step has a negative influence on the catalyst, which loses some catalytic activity. The optimum procedure in terms of quality and chlorine content of the products is the combination of first a low temperature step without catalyst, and second the catalytic pyrolysis step.

Tocopheryl acetate nanoemulsions stabilized with lipid–polymer hybrid emulsifiers for effective skin delivery

Tocopheryl acetate is used as the oil component of nanoemulsions using a mixture of unsaturated phospholipids and polyethylene oxide-block-poly(ɛ-caprolactone) (PEO-b-PCL). This study investigates the effects of the lipid–polymer composition on the size and surface charge of nanoemulsions, microviscosity of the interfacial layer, and skin absorption of tocopheryl acetate. The lipid–polymer hybrid system exhibits excellent colloidal dispersion stability, which is comparable to that of polymer-based nanoemulsions. If lipids are used as emulsifiers, nanoemulsions show poor dispersion stability despite a good skin absorption enhancing effect. The amount of tocopheryl acetate absorbed by the skin increases with an increased lipid-to-polymer ratio, as determined using the hairless guinea pig skin loaded in a Franz-type diffusion cell. An 8:2 (w/w) mixture of unsaturated phospholipids and PEO-b-PCL exhibits the most efficient delivery of tocopheryl acetate into the skin. Our results show that tocopheryl acetate is absorbed almost twice as fast by the lipid–polymer hybrid system than the nanoemulsions stabilized with PEO-b-PCL. This study suggests that the lipid–polymer hybrid system can be used as an effective means of optimizing nanoemulsions in terms of dispersion stability and skin delivery capability.

E203 廃家電製品プラスチックからの熱分解油化技術(OS3 バイオマス・新燃料・環境技術)

Brominated flame retardant plastics are used the various electrical and electronics (E&E) to prevent fire accidents. Even though these plastics may not burn easily, it is difficult to recycle after used. In this study, virgin and waste fraction of acrylonitrile butadiene styrene (ABS) containing brominated flame retardants were pyrolyzed at 450℃. Experiments were carried out to observe the effects of sodium hydroxide (NaOH), adsorbent (pine charcoal) and polyethylene for the removal of bromine. The analysis of the pyrolysis oils showed that the oils were mainly composed of toluene, ethylbenzene, styrene, cumene, α-methylstyrene and isopropylphenol. As the bromine compound was detected phenol 2-bromo. The contents of bromine in pyrolysis oil produced about 2.64, 3.2 and 3.5 wt % when it was without any additive at 450℃. When NaOH was added, the bromine content was decreased to 0.45, 1.2 and 1.25 wt%, respectively. When NaOH and with adsorbents were used, the content of bromine in oil was decreased to 0.36, 0.6 and 0.87wt%, respectively. If the mixture of polyethylene (1:1) was added, the content of bromine in oil was decreased to 0.1, 0.99 and 1.0 wt%.

1203 混合プラスチック選別装置における回収モデルの開発(G02-2 選別装置と放電加工,G02 機械材料・材料加工邵門)

In this study, theoretical and experimental studies of electrostatic separation of plastic mixtures were conducted. The separator consists of four cylindrical electrodes. The principle of the separation is based on the difference between Coulomb forces acting on plastic particles. The separation of a mixture of polyethylene(PE) and polypropylene(PP) particles was studied. All particles were obtained from shredded cap of plastic bottle. An analytical solution based on the charge distribution for particles is presented. It is show that the approach in this study is effective for estimating the recovery of plastics.

Nickel(II) catalysed co-polymerisation of CO and ethene: Formation of polyketone vs. polyethylene – The role of co-catalysts

The square planar Ni complex (SP-4-3)-[Ni(2-tol)(PPh 3)(N,O)] (N,O = (Z)-4,4,5,5,6,6,6-heptafluoro-3-oxo-2-(pyrrolidine-2-ylidene)-hexanenitrile) is an active catalyst for the co-polymerisation of CO and ethene yielding aliphatic polyketone. Addition of Lewis acids like BPh 3 or B(C 6F 5) 3 as co-catalyst accelerates the polymerisation but not the lifetime of the catalyst and leads to a mixture of polyethylene and polyketone. Addition of the Lewis base triphenylphosphane (PPh 3) completely suppresses the formation of polyethylene. The polymers formed were characterised by IR spectroscopy, 13C cross polarisation (CP) magic angle spinning (MAS) solid state NMR spectroscopy, differential scanning calorimetry (DSC) and size exclusion chromatography (SEC).

Influence of colloidal structure of polymer mixes on adhesion strength of polyolefin compositions

Mixtures of low-density polyethylene and ethylene-vinyl acetate (EVA) copolymer are studied. It is shown that the adhesion value is defined by the polymer that forms a dispersion medium in the adhesive compositions and the type of fracture depends on the competing influence of the physical and mechanical parameters and the reduced acidity parameter of the polymer, which forms a continuous phase.