Search results for " MECHANICAL PROPERTIES"

Mechanical properties of nanostructured carbon layers grown by CVD and PLD techniques

2010

Pulsed laser deposition (PLD) and chemical vapour deposition (CVD) have been proven to be among the most successful techniques for growing the entire spectrum of carbon films, which can be used in a wide range of technical applications. Here an investigation has been performed to explore the effect of different growing techniques (PLD and CVD) and process parameters (such as deposition time and substrate type) on the films' morphology and mechanical properties. The mechanical properties of the grown thin films were characterised by means of nano/micro indentation and scratch test techniques. It was observed that the thickness of the Al2O3 interlayer (between the Fe catalyst nanoparticles an…

UNEVEN DISTRIBUTION OF ORGANOCLAY IN HDPE/PA6 BLENDS - IMPACT OF MICROSTRUCTURE AND MECHANICAL BEHAVIOUR

2009

Multi-functional hindered amine light stabilizers-functionalized carbon nanotubes for advanced ultra-high molecular weight Polyethylene-based nanocom…

2015

Hindered Amine Light Stabilizer (HAS) molecules have been covalently linked on the outer surface of multi-walled carbon nanotubes (CNTs), and the so-obtained multi-functional fillers (HAS-f-CNTs) have been compounded with Ultra High Molecular Weight Polyethylene (UHMWPE) to get composite films. The success of the grafting reaction of the HAS molecules has been confirmed through spectroscopic and thermo-gravimetric analyses. Morphological analyses reveal a segregated microstructure, in which CNT-rich channels surround the polymer domains. This morphology results in improved mechanical properties and appreciable electrical conductive features. More importantly, the addition of only 1 wt.% of …

“Effect of Filler Type and Processing Apparatus on the Properties of the Recycled “Light Fraction” from Municipal Post-Consumer Plastics”

2001

Plastic waste or scraps are generated from two main sources: industrial wastes and post-consumer wastes. By using the flotation method, generally two fractions are obtained from municipal post-consumer wastes: a light fraction, floating on water, and a heavy fraction. The former is essentially made of low and high density polyethylene—LDPE, HDPE—and polypropylene—PP; the heavy fraction is formed by poly(vinyl chloride)—PVC—and poly(ethylene terephthalate)—PET. In this work, the recycling of a light fraction from municipal post-consumer plastics has been studied, considering also the effect of filler type—glass fibres, calcium carbonate and wood fibres—and processing apparatus—discountinous …

Effect of the processing on the properties of biopolymer based composites filled with wood flour

2008

Wood-polymer composites (WPCs) are well known today in the field of industrial applications, because of several advantages they can grant if compared with mineral filler-polymer composites. These advantages regard the low cost of wood based fillers, the reduced specific weight, the lower hazards for production workers in case of inhalation, the special aesthetic features, environmental issues. The scientific literature reports studies regarding polymer matrices like, for instance, polyethylene and polypropylene, in combination with several natural-organic fillers. However, a limit of these composites is represented by the fact that there is not a full biodegradability: this, in fact, regard…

Influence of the e-beam irradiation and photo-oxidation aging on the structure and properties of LDPE-OMMT nanocomposite films

2012

Abstract In this paper two systems, polyethylene (LDPE) and polyethylene/commercial organo-modified montmorillonite (LDPE/OMMT) nanocomposite, were subjected to e-beam irradiation at different doses and both the molecular modifications and mechanical properties have been investigated through solubility, FT-IR, calorimetric and tensile tests. Moreover, in some of the irradiated systems photo-oxidation aging was performed and its effects were studied. The results show an enhancement with irradiation of the positive effect of the nano-filler loading, related to the increase of the mechanical properties, due to the increase of the nano-filler polymer interaction. Nevertheless calorimetric and F…

Effect of the construction process on the performances of asphalt paving mixes with crumb rubber from scrap tires

2004

This paper presents the results of an experimental study on the use of CRM (Crumb Rubber Modifier) in bituminous mixtures for asphalt pavements, using a Dry Process. Employing experimental methods capable of ensuring that the mixtures obtained and the stress conditions that they undergo in pavements are representative, we clarify some aspects relating to the design and production of mixtures; we also show the effects of the bitumen-rubber interaction on mechanical performances (fatigue resistance and rutting). Among the various factors involved in manufacture, a particular investigation was carried out on the effects of asphalt content, mixing temperatures and mixture compaction. The experi…

Fabrication Techniques for Electrospun Polyurethane Scaffolds that Generate Valve Leaflet Mechanical Properties.

2010

Reprocessing of polyethyleneterephthalate and characterisation of monopolymer blends of virgin and recycled polymers

1997

Recycling of polyethyleneterephthalate (PET from bottles is considered by changing both reprocessing machines and the effect of humidity. The rheological and mechanical properties of this recycled material remain very close to that of the virgin material provided that a careful drying is carried out before any melt operation. The reprocessing has been carried out mainly in view of the use of this secondary material in blends with virgin PET-monopolymer or homopolymer blends. Indeed, this use is a common industrial practice to reuse plastic scraps. Most monopolymer blends show properties between those of the two components but in some cases lower than those expected on the basis of an additi…

Modelling the structure-property relationships of high performance PBAT-based biocomposites with natural fibers obtained from Chamaerops humilis dwar…

2022

Two fibrous fillers were achieved from stalks and leaves of Chamaerops humilis dwarf palm and tested as reinforcing agents for poly(butylene adipate co-terephthalate) (PBAT)-based composites. The influence of filler type and content on the morphomechanical properties of the green composites was assessed. The outcomes of tensile tests pointed out that both fillers are strong candidates to overcome the two main limiting aspects of PBAT, that is, the lack of both stiffness and cost-effectiveness, while preserving its stretchability and environmental sustainability. The remarkable stiffness increments (up to 300%), combined with fair retention of stretchability (33%) and doubled resistance, led…