Search results for " polyethylene"
showing 10 items of 229 documents
Multi-functional polyhedral oligomeric silsesquioxane-functionalized carbon nanotubes for photo-oxidative stable Ultra-High Molecular Weight Polyethy…
2016
Abstract Nanohybrid (phPOSS- f -CNTs) based on Carbon Nanotubes (CNTs) and Phenyl Polyhedral Olygomenric Silsesquioxane (phPOSS) have been synthesized to be used as multifunctional filler for polymer nanocomposites. The success of the functionalization procedure has been demonstrated via accurate spectroscopic, spectrometric and thermo-gravimetric analyses. The results reveal that a large portion of phPOSS is covalently linked to CNTs, while a small amount of phPOSS remains physically adsorbed due to the strong interactions coming from π electron coupling between the CNTs and phenyl rings in phPOSS. Small amounts (1 wt.%) of phPOSS- f -CNTs have been dispersed in Ultra High Molecular Weight…
Photooxidation Behavior of a LDPE/Clay Nanocomposite Monitored through Creep Measurements
2017
Creep behavior of polymer nanocomposites has not been extensively investigated so far, especially when its effects are combined with those due to photooxidation, which are usually studied in completely independent ways. In this work, the photooxidation behavior of a low density polyethylene/organomodified clay nanocomposite system was monitored by measuring the creep curves obtained while subjecting the sample to the combined action of temperature, tensile stress, and UV radiation. The creep curves of the irradiated samples were found to be lower than those of the non-irradiated ones and progressively diverging, because of the formation of branching and cross-linking due to photooxidation. …
Recycling of heterogeneous plastics wastes: I—Blends with low-density polyethylene
1992
Abstract Heterogeneous plastics wastes are usually recycled by means of ad hoc designed equipment which, in a single step, produces objects with large dimensions and poor mechanical properties. In this preliminary work, the possibility of preparing blends of plastics waste and low-density polyethylene is investigated. These ‘secondary’ materials (with plastics waste content up to 50%) show mechanical properties similar, except for the elongation at break, to those of the virgin polyethylene. The addition of moderate amounts of calcium carbonate does not significantly reduce the properties of these materials.
Mechanical Properties of High-Density Polyethylene/Chlorinated Polyethylene Blends
2004
Results of experimental investigation of mechanical properties of high-density polyethylene (HDPE)/chlorinated polyethylene (CPE) blends in tension are reported. The specimens of pure HDPE, CPE, and nine types of HDPE/CPE blends, with different component ratios at 10 wt.% intervals, are examined. The features of the stress-strain curves obtained are discussed. Data on the influence of blend composition on the elastic modulus, yield stress, breaking stress, and ultimate elongation are obtained. The results of investigations into the creep behavior are also presented. It is found that the creep compliance obeys the power law of creep with coefficients depending on blend composition.
Morphology and properties of blends of polyethylene with a semiflexible liquid crystalline polymer
1995
Blends of three polyethylene (PE) samples (two HDPE grades and LLDPE) with an experimental sample of a semiflexible liquid crystalline polymer (SBH 1 :1 :2 by Eniricerche) have been prepared in a Brabender compounder. The processing-aid effect of the LCP has been demonstrated by the decreased energy required for extruding the blends, as compared to that needed for neat PE. The thermal properties, as studied by differential scanning calorimetry (DSC), have shown that the two components of the blends are immiscible. However, the dispersed SBH phase has been found to act as a nucleating agent for the crystallization of LLDPE, whereas no such effect was observed for HDPE. This has been taken as…
Structure and properties of nylon 6 modified by ?-irradiated linear low density polyethylene
1993
In this work, structure and properties of blends of nylon 6 with 10% linear low density polyethylene γ-irradiated in air at different integrated doses are presented. More particularly, Molau tests, DSC, SEM, and mechanical tests have been performed. Results show that positive morphological changes with respect to the blend with unirradiated linear low density polyethylene are well evident, especially in the blend with polyethylene irradiated at 50 KGy. This blend also shows an enhancement of the elongation at break and of the impact properties.
Mechanical properties-structure relationship in blends of polyamide 6 with γ-irradiated LDPE
1993
Blends of γ-irradiated and unirradiated low density polyethylene with polyamide 6 were made in order to study possible modifications induced by this irradiation. Blends with γ-irradiated polyethylene show structure and properties significantly different with respect to blends made with the unirradiated polyethylene. In this paper data on mechanical properties (tensile and impact) of these blends are presented. Results are related to the different morphologies in the blends.
Structure and dynamics of polyethylene/clay films
2006
The relationships between structure and rheology of polyethylene/clay hybrid composite blown films were investigated through rheological tests both in shear and elongational flow. Two polymer matrices (low density polyethylene, LDPE and linear low density polyethylene, LLDPE) with different relaxation kinetics were used. Independently from the matrix, morphological analyses (TEM, XRD, and SEM) indicate that the hybrid structures are similarly constituted of delaminated platelets or tactoids having a relevant degree of orientation along the draw direction. This strongly affects the rheological behavior of materials. However, despite the similarities emerged from morphological analyses, both …
High-density polyethylene facial implants show surface oxidation in SEM and EDX examination: a pilot study.
2009
Previous histopathological studies on explanted Medpor high-density polyethylene (HDPE) facial implants indicated signs of material destruction and claimed to observe phagocytized HDPE particles within the tissue samples beside the usual type IV reaction with severe fibrosis. We examined new and explanted Medpor material with scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The implant surface of three patient-derived specimens showed significantly higher oxygenation in EDX analysis and morphological changes in SEM compared to the new unused material directly after opening of the package and after 1 year of exposure to air. Our preliminary findings indicate a p…
Model of partial crystallization and melting derived from small-angle X-ray scattering and electron microscopic studies on low-density polyethylene
1980
A temperature-dependent small-angle x-ray scattering and electron microscopic study on a sample of low-density polyethylene affords a determination of the structure changes in a heating and cooling cycle and suggests a new model of partial crystallization and melting. The analysis of SAXS data is based upon some general properties of the electron-density correlation function. Electron micrographs are obtained from stained sections γ irradiated at elevated temperatures and are analyzed quantitatively by statistical means. According to the model proposed here the thickness distribution in the amorphous layers, rather than that of the crystalline regions, is the essential factor governing the …