Search results for "polymer-matrix composites"
showing 10 items of 30 documents
Quasi-static behaviour and damage assessment of flax/epoxy composites
2015
Experimental investigations were conducted on flax and E-glass fibres reinforced epoxy matrix composites subjected to quasi-static loadings. Flax/epoxy samples having [0]12, [90]12, [0/90]3S and [±45]3S stacking sequences, with a fibre volume fraction of 43% have been tested under tension, compression and in-plane shear loadings. Overall, the compression strength of glass/epoxy was 76% greater than for the flax/epoxy composite. The damage evolution of flax/epoxy of [0/90]3S and [±45]3S samples has been evaluated in terms of transverse crack densities with respect to the load increment. The crack density exhibited a classical “S” shaped pattern for [0/90]3S and linearly for [±45]3S specimens…
Green composites: A brief review
2011
The rising concern towards environmental issues and, on the other hand, the need for more versatile polymer-based materials has led to increasing interest about polymer composites filled with natural-organic fillers, i.e. fillers coming from renewable sources and biodegradable. The composites, usually referred to as "green", can find several industrial applications. On the other hand, some problems exist, such as worse processability and reduction of the ductility. The use of adhesion promoters, additives or chemical modification of the filler can help in overcoming many of these limitations. These composites can be further environment-friendly when the polymer matrix is biodegradable and c…
Effect of filler on the creep characteristics of epoxy and epoxy-based CFRPs containing multi-walled carbon nanotubes
2014
The aim of this work was to determine the effect of carbon nanotubes (CNTs) on the elastic and viscoelastic properties of an epoxy resin used in carbon fiber-reinforced plastics (CFRPs) in the matrix-dominated flexural testing mode. Neat and CNTs-containing (1. wt.%) epoxy resin and CFRP specimens were prepared and investigated. Three-point bending tests were carried out on nanocomposite (NC) and CFRP specimens at room temperature in quasi-static and cyclic creep regimes. The main effect of CNTs was observed in the reduction of creep compliance of epoxy (40%) and CFRP (30%), especially at higher stresses. The reduction of creep characteristics especially on viscoelastic and plastic strains …
Processing and characterization of highly oriented fibres of biodegradable nanocomposites
2015
Abstract Biodegradable polymeric materials are becoming day by day ever more important in packaging, agriculture, single-use cutleries and other large consumer applications. The major part of those materials is used under the form of film, i.e. subjected to elongational flow, but the main problem is that they often offer poor mechanical properties. Adding nanofillers, like Multi Walled Carbon Nanotubes (MWCNTs) may solve this problem but only if there is a full control of their orientation inside the material. Aim of this work is to investigate the processing-properties-morphology relationships for a system prepared under elongation flow of MaterBi and commercial MWCNTs. The materials were …
High performance composites containing perfluoropolyethers-functionalized carbon-based nanoparticles: Rheological behavior and wettability
2016
Abstract Ultra High Molecular Weight Polyethylene (UHMWPE) based composites filled with carbon nanotubes (CNTs) and carbon black (CB) modified by perfluoropolyethers (PFPE) have been formulated. All composites show a segregated morphology with nanofillers selectively localized at the polymer particle–particle interface. The composites rheological properties have been deeply investigated: the PFPE functionalities linked on CNTs facilitate the semi-3D nanofillers network formation in the composites that show a solid-like behaviour even at lower investigated filler contents, reaching the rheological percolation threshold at lower nanofiller content than bare CNTs filled composites. For composi…
A review on basalt fibre and its composites
2015
Abstract In recent years, both industrial and academic world are focussing their attention toward the development of sustainable composites, reinforced with natural fibres. In particular, among the natural fibres (i.e. animal, vegetable or mineral) that can be used as reinforcement, the basalt ones represent the most interesting for their properties. The aim of this review is to illustrate the results of research on this topical subject. In the introduction, mechanical, thermal and chemical properties of basalt fibre have been reviewed. Moreover, its main manufacturing technologies have been described. Then, the effect of using this mineral fibre as reinforcement of different matrices as po…
On the response of flax fiber reinforced composites under salt-fog/dry conditions: Reversible and irreversible performances degradation
2022
Abstract Despite their scarce resistance to humid or wet conditions, natural fiber reinforced composites (NFRCs) seem to be able to partially recover their performances under discontinuous exposition to marine environment. To investigate this peculiarity, flax fiber reinforced composite was at first subjected to salt-fog spray condition at 35 °C for 15 and 30 days, respectively, and then stored in ‘‘dry” condition (i.e., 50% R.H. and 22 °C) between 0 and 21 days. The performances evolution was evaluated through flexural tests, water uptake and contact angle measurements. Moreover, the morphology of fractured mechanical samples was examined by using 3D optical microscope and scanning electro…
A novel approach to prevent graphene oxide re-aggregation during the melt compounding with polymers
2015
Abstract The technology for the preparation of polymer-GO nanocomposites was investigated by studying the structure-properties relationships of two different systems, based on PA6 and EVA, fabricated by using different preparation methods, i.e. melt mixing, wet phase inversion, and the combination of the two. The morphology of nanocomposites resulted dramatically influenced by the technique adopted and showed to be the critical variable affecting the physical properties of the materials. Finally, the mechanical and dynamic-mechanical of the nanocomposites were improved by using the hybrid technique combining the two procedures.
Effects of aging in salt spray conditions on flax and flax/basalt reinforced composites: Wettability and dynamic mechanical properties
2016
Abstract In the last years, the industrial policies are more attentive to issues concerning sustainability, recycling and environmental care. Therefore, the use of natural fibres in composite materials has spread more and more. This paper deals with flax and basalt fibres within an epoxy matrix by investigating the wettability and the dynamic mechanical properties of the resulting composites, subjected to long-term aging tests in critical environmental conditions. The first laminate was constituted by stacking ten layers of bidirectional flax fabrics. The second one was produced by replacing two external flax layers with two layers of basalt mat, for each side of the laminate. Both laminate…
An insight into the interaction between functionalized thermoplastic elastomer and layered double hydroxides through rheological investigations
2018
Abstract Nanocomposites based on maleated poly(styrene-(ethylene-co-butylene)-styrene) copolymer (SEBSgMA) and organo-modified layered double hydroxide (OLDH) have been formulated with the aim to investigate the effects of interfacial interactions between the grafted maleic anhydride groups of the copolymer and the OLDH nanolayers on the rheological properties of nanocomposites. The spectroscopic analysis indicates the establishment of specific polymer/nanofiller interactions, whose extent has been highlighted through morphological and rheological investigations. Specifically, oscillatory melt rheology and shear relaxation tests have been considered in order to deeply investigate the interf…