oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Polyethylene/synthetic boehmite alumina nanocomposites: Structure, thermal and rheological properties
eXPRESS Polymer Letters , 2010, DOI: 10.3144/expresspolymlett.2010.34
Abstract: Synthetic boehmite alumina (BA) has been incorporated up to 8 wt% in low density polyethylene (LDPE) and high density polyethylene (HDPE), respectively, by melt compounding. The primary nominal particle size of these two BA grades was 40 and 60 nm, respectively. The dispersion of the BA in polyethylene (PE) matrices was investigated by scanning and transmission electron microscopy techniques (SEM and TEM). The thermal (melting and crystallization), thermooxidative (oxidation induction temperature and time), and rheological behaviors of the nanocomposites were determined. It was found that BA is nanoscale dispersed in both LDPE and HDPE without any surface treatment and additional polymeric compatibilizer. BA practically did not influence the thermal (melting and crystallization) and rheological properties of the parent PEs. On the other hand, BA worked as a powerful thermooxidative stabilizer for LDPE, and especially for HDPE nanocomposites.
Thermal Stability and Rheological Behaviors of High-Density Polyethylene/Fullerene Nanocomposites
Liping Zhao,Ping'an Song,Zhenhu Cao,Zhengping Fang,Zhenghong Guo
Journal of Nanomaterials , 2012, DOI: 10.1155/2012/340962
Abstract: High-density polyethylene/fullerene (HDPE/C60) nanocomposites with the C60 loading that varied from 0.5 to 5.0% by weight were prepared via melt compounding. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) results showed that the presence of C60 could remarkably enhance the thermal properties of HDPE. A very low C60 loading (0.5 wt%) increased the onset degradation temperature from 389°C to 459°C and decreased the heat release from 3176 J/g to 1490 J/g. The larger the loading level of C60, the better the thermal stability of HDPE/C60 nanocomposites. Rheological investigation results showed that the free radical trapping effect of C60 was responsible for the improved thermal stability of HDPE.
The Effect of Poly-Ethylene-co-Glycidyl Methacrylate Efficiency and Clay Platelets on Thermal and Rheological Properties of Wood Polyethylene Composites  [PDF]
Ansou Malang Badji, El Hadj Babacar Ly, Diene Ndiaye, Abdou Karim Diallo, Ndickou Kebe, Vincent Verney
Advances in Chemical Engineering and Science (ACES) , 2016, DOI: 10.4236/aces.2016.64040
Abstract: Global ecological concerns have resulted in an interest in renewable natural materials. Composites based on high density polyethylene (HDPE), wood fiber (Veneer) and containing coupling agents like nanoclay (NC) and poly-ethylene-co-glycidyl methacrylate (PEGMA) were made by melt compounding and then injection molding. In this study, the effects of two variable parameters namely nanoclay and coupling agent on the rheological and thermal properties of wood polyethylene composites (WPECs) were investigated. The study investigates the morphology phase, rheology behaviors and thermal properties by scanning electron microscope, capillary rheometer and thermal gravimetric analyzer. The SEM micrographs of the composites showed that the outer surfaces of the wood were coated by a section of amorphous lignin. The state of dispersion in HDPE/pine/clay composites was improved by EGMA because it could interact with pine flour in addition to clay. The interaction of reinforcement with coupling agent and HDPE matrix is strong based on the observation of the fracture surface of composites when EGMA is present. However the addition of 2.5% clay slightly lowered the initial degradation temperature (Td) but did not improve the thermal stability. Obviously, all the composites materials exhibit viscoelastic values greater than those of neat HDPE.
Mechanical, Thermal and Crystallization Properties of Polypropylene (PP) Reinforced Composites with High Density Polyethylene (HDPE) as Matrix  [PDF]
Harekrushna Sutar, Prakash Chandra Sahoo, Prateekshya Suman Sahu, Surajabala Sahoo, Rabiranjan Murmu, Sumit Swain, Subash Chandra Mishra
Materials Sciences and Applications (MSA) , 2018, DOI: 10.4236/msa.2018.95035
Abstract: Our work aims to evaluate a complete outlook of virgin high density polyethylene (HDPE) and polypropylene (PP) polyblends. Virgin PP of 20, 30 and 50 weight% is compounded with virgin HDPE. The properties like tensile strength, flexural strength, Izod impact strength are examined. Scanning electron microscopy (SEM) and polarised light microscopy (PLM) are used to observe the surface and crystal morphology. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) tests verify the non compatibility of both polymers. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques are used to study the thermal behaviour of composites. The results manifest co-occurring spherulites for polyblends; indicating the composite to be a physical blend of continuous and dispersed phases, but on the other hand PP improves the tensile and flexural properties of HDPE.
Study of the Thermal, Rheological, Morphological and Mechanical Properties of Biocomposites Based on Rod-Of Typha/HDPE Made up of Typha Stem and HDPE  [PDF]
Babacar Niang, El Hadj Babacar Ly, Abdou Karim Diallo, Nicola Schiavone, Haroutioun Askanian, Vincent Verney, Ansou Malang Badji, Mahmoud Kalid Diakite, Diéne Ndiaye
Advances in Materials Physics and Chemistry (AMPC) , 2018, DOI: 10.4236/ampc.2018.89023
Abstract:
The thermal, rheological and morphological properties of composite biomaterials made with mixture of high density polyethylene and typha rod powder (RD) were evaluated. The dynamic mechanical behavior of the samples was studied with 25%, 35% and 45% typha stem powder concentrations. The viscoelastic properties are mainly related to the nature of the polymer and the typha stem powder. Storage (G') and loss (G\") moduli increased significantly, depending on the amount of powder in the molten mixture. After a viscosity increase was noticed in low frequency, it decreased in high frequencies, which demonstrates the pseudo-plasticity effect. Morphological and thermal characterization results have shown the dispersion state of the powder and its ability to modify the kinetics crystallization of biocomposites.
The effects of particle size and content on the thermal conductivity and mechanical properties of Al2O3/high density polyethylene (HDPE) composites
eXPRESS Polymer Letters , 2011, DOI: 10.3144/expresspolymlett.2011.57
Abstract: The influences of filler size and content on the properties (thermal conductivity, impact strength and tensile strength) of Al2O3/high density polyethylene (HDPE) composites are studied. Thermal conductivity and tensile strength of the composites increase with the decrease of particle size. The dependence of impact strength on the particle size is more complicated. The SEM micrographs of the fracture surface show that Al2O3 with small particle size is generally more efficient for the enhancement of the impact strength, while the 100 nm particles prone to aggregation due to their high surface energy deteriorate the impact strength. Composite filled with Al2O3 of 0.5 μm at content of 25 vol% show the best synthetic properties. It is suggested that the addition of nano-Al2O3 to HDPE would lead to good performance once suitably dispersed.
Thermal, Mechanical and Rheological Properties of Low Density/Linear Low Density Polyethylene Blend for Packing Application  [PDF]
F. Al-Attar, M. Alsamhan, A. Al-Banna, J. Samuel
Journal of Materials Science and Chemical Engineering (MSCE) , 2018, DOI: 10.4236/msce.2018.61005
Abstract:
Packaging is the subject of considerable commercial development by a variety of organizations around the world. In this study the mechanical, thermal and rheological properties were investigated for different blend ratios of low density polyethylene (LDPE) and linear low density polyethylene (LLDPE). The weight percent of the LDPEs used in the blends were 50, 60, 70, 80 and 90. The polymer blends were prepared in a twin screw extruder to produce a thin sheet (1-mm thickness) similar to the packaging grade. Tensile results showed that the 50/50 composition exhibited the highest stress at break, where the differential scanning calorimetry results indicated a co-crystalline phase in some blends. The results produced by the rheometer revealed the LLDPE effect over the complex viscosity and consequently blend easy processing. The present study conclusively demonstrates that at low weight percent of linear low density polyethylene in the blend displays better properties for packaging application.
Mechanical, Thermal, Morphological and Rheological Properties of Polypropylene/Ultrahigh Molecular Weight Polyethylene Blends
Mechanical, Thermal, Morphological and RheologicalProperties of Polypropylene/Ultrahigh Molecular Weight Polyethylene Blends

Xiaodong WANG,Riguang JIN,Hangquan LI,

材料科学技术学报 , 1995,
Abstract: In this study, the blends of polypropylene (PP) and ultrahigh molecular weight polyethylene (UHMWPE) were prepared by the four-and twin-screw extruders, and ethylene-propylene-diene monomer (EPDM), as the third component, was added to the binary blends. The mechanical.thermal, morphological and rheological properties of these two blends have been investigated.For the materials blended by the four-screw extruder, a 15 wt-% content of UHMWPE corresponds to a maximum lzod impact strength, and the miscibility enhancement effect of EPDM on PP/UHMWPE blends is very remarkable. Mechanical and thermal properties demonstrate that melt blending by the four-screw extruder is a better prcessing method for PP/UHMWPF blends than that by the twin-screw extruder. A co-continuous structure was observed in blends through TEM, and a novel "linear interpenetrating" toughening mechanism is proposed on the basis of this research work
Recovery of hydrocarbon liquid from waste high density polyethylene by thermal pyrolysis
Kumar, Sachin;Singh, R. K.;
Brazilian Journal of Chemical Engineering , 2011, DOI: 10.1590/S0104-66322011000400011
Abstract: thermal degradation of waste plastics in an inert atmosphere has been regarded as a productive method, because this process can convert waste plastics into hydrocarbons that can be used either as fuels or as a source of chemicals. in this work, waste high-density polyethylene (hdpe) plastic was chosen as the material for pyrolysis. a simple pyrolysis reactor system has been used to pyrolyse waste hdpe with the objective of optimizing the liquid product yield at a temperature range of 400oc to 550oc. results of pyrolysis experiments showed that, at a temperature of 450oc and below, the major product of the pyrolysis was oily liquid which became a viscous liquid or waxy solid at temperatures above 475oc. the yield of the liquid fraction obtained increased with the residence time for waste hdpe. the liquid fractions obtained were analyzed for composition using ftir and gc-ms. the physical properties of the pyrolytic oil show the presence of a mixture of different fuel fractions such as gasoline, kerosene and diesel in the oil.
NANOFILLER REINFORCEMENT EFFECTS ON THE THERMAL, DYNAMIC MECHANICAL, AND MORPHOLOGICAL BEHAVIOR OF HDPE/RICE HUSK FLOUR COMPOSITES
Behzad Kord
BioResources , 2011,
Abstract: Polymer nanocomposites reinforced with lower volume fractions of nanofiller have recently attracted steadily growing interest due to their peculiar and fascinating properties as well as their unique applications in commercial sectors. In this study, composites based on high density polyethylene and rice husk flour with different loading of nanoclay were fabricated in an internal mixer. The influence of nanofiller at four levels (0, 2, 4, and 6 per hundred compounds (phc)) on the thermal and rheological behavior was studied. The morphology of nanoclay was determined by X-ray diffraction (XRD), and the effect of morphology on the thermal and dynamic mechanical properties were considered. Results indicated that the crystallization temperature, crystallization enthalpy, and crystallinity level increased with increase of nanoclay up to 2 phc and then decreased. Also, the dynamic mechanical behavior of composites was improved by the addition of nanofiller. X-ray diffraction patterns (XRD) revealed that the nanocomposites formed were intercalated. Morphological findings showed that samples containing 2 phc of nanoclay had higher order of intercalation and better dispersion. It seems that the thermal and dynamic mechanical properties of the HDPE/rice husk flour composites were improved by increasing addition of coupling agent.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.