Search results for "MECHANICAL PROPERTIES"
showing 10 items of 199 documents
Electronic Transport in carbon nanotubes under traction, bending, torsion and misalignment of the two ends
2013
Electrical conductance in carbon nanotubes under mechanical deformation
2013
Fabrication Techniques for Electrospun Polyurethane Scaffolds that Generate Valve Leaflet Mechanical Properties.
2010
Environmental aging effects on high-performance biocomposites reinforced by sisal fibers
2023
Among the innovative materials, an important role is played by the so-called biocomposites, generally made by an eco-friendly matrix reinforced with natural fibers. Unfortunately, due to the degradability of the green matrixes as well as to hydrophilicity of the natural fibers, the resistance of such innovative materials to the environmental agents is, in general, relativity low, and it can significantly limit their use in outdoor conditions. To contribute to the knowledge of the effects of the leading environmental agents on the mechanical properties of highperformance biocomposites made of a green epoxy matrix reinforced by agave fibers, a systematic experimental testing campaign has been…
Mechanics of carbon nanotube reinforced nanocomposites
2014
Many numerical models have been developed in attempts to improve the understanding of the stiffening effects of CNTs in a polymer matrix. These studies are based on the micromechanical models, because the atomistic models are computationally too expensive to simulate the behavior of the composite. We emphasize that the majority of these continuum micromechanical models either explicitly or effectively adopt an assumption of an ideally-bonded interface between the compliant polymer matrix and the stiff CNTs, and often lead to predictions of overall composite stiffness that are quite optimistic compared to experimental results. Here the effects of waviness, diameter and volume fraction of CNT…
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…
The Use of Waste Hazelnut Shells as a Reinforcement in the Development of Green Biocomposites.
2022
Biodegradable Mater-Bi (MB) composites reinforced with hazelnut shell (HS) powder were prepared in a co-rotating twin-screw extruder followed by compression molding and injection molding. The effects of reinforcement on the morphology, static and dynamic mechanical properties, and thermal and rheological properties of MB/HS biocomposites were studied. Rheological tests showed that the incorporation of HS significantly increased the viscosity of composites with non-Newtonian behavior at low frequencies. On the other hand, a scanning electron microscope (SEM) examination revealed poor interfacial adhesion between the matrix and the filler. The thermal property results indicated that HS could …
Effect of sheep wool fibres on thermal-insulation and mechanical properties of cement matrix
2015
The use of sheep wool as reinforcement of cement in order to produce mortar or plaster involves several advantages for environment and energy. Moreover, in several regions it is treated as a waste and, consequently, its employ is characterized by low cost. Aim of this paper is to evaluate the influence of wool fibres on thermal conductivity and mechanical properties of cement. The samples were prepared using wool fibres, obtained from a breed of Sicilian sheep, with three different length (i.e. 1 mm, 6 mm and 20 mm). Moreover, in order to evaluate the influence of fibre content, the samples were prepared by varying the fibres weight fraction up to maximum level. The thermal conductivity of …
Flax–Glass Fiber Reinforced Hybrid Composites Exposed to a Salt-Fog/Dry Cycle: A Simplified Approach to Predict Their Performance Recovery
2023
Despite natural fibers gaining significant attention in recent decades, their limited performance and poor durability under humid environments cannot allow them to fully replace their synthetic counterparts as reinforcement for structural composites. In such a context, this paper aims to investigate how exposure to a humid/dry cycle affects the mechanical response of epoxy laminates reinforced with flax and glass fibers. In particular, the main goal is to assess the performance evolution of a glass–flax hybridized stacking sequence in comparison with the full glass and flax fiber reinforced composites. To this end, the investigated composites were first exposed to salt-fog for 15 or 30 days…