A comparative assessment of three lignocellulosic fibres obtained from leaf, bast and fruit on th... more A comparative assessment of three lignocellulosic fibres obtained from leaf, bast and fruit on the mechanical and thermal properties of fully biodegradable composites has been performed.
The development of casein-based plastics is, together with starch-based one, an alternative to c... more The development of casein-based plastics is, together with starch-based one, an alternative to conventional ones, produced from hydrocarbons and their derivatives. Though dating back to late XIX century, under the principal name of galalith, its interest has been revived recently, also due to the efforts taken into implementation of circular economy, therefore to the waste-to-materials process. This recognizes the abundance of refuse derived from the dairy products sector, which allowed casein also entering the field of material tinkering for design. In a more industrial sense, a number of works exist in the last two decades focused on the revival of casein-based materials, mostly, yet not exclusively, in a formaldehyde-free version. These include a particular attention to the creation of packaging films, in some cases edible ones, which includes the experimentation on the effect of different plasticizers, such as polyols e.g., glycerol and sorbitol, and blending with starch or pectins. Other applications are being furthermore explored, which include biomedical use of casein films especially as wound dressing, the use of casein in the production of fibers, for textile and antibacterial purposes. In general terms, studies on casein materials are aimed at serving to the replacement of oil-based plastics, or as the matrix for natural fiber composites.
Most recently, there has been an increasing interest for the production of laminates for semi-str... more Most recently, there has been an increasing interest for the production of laminates for semi-structural applications using sustainable materials. In this field, a possible option is the use of composites including ligno-cellulosic fibers, which are normally obtained as by-products from the textile industry, therefore mainly in the form of fabric or mats. Despite a reasonably large amount of studies on thermosetting composites reinforced with vegetable fibers also exist, in the view to replace fiberglass e.g., in the automotive industry, it is clear on the other side that the evolution of natural fiber composites has a much stronger drive towards the use of thermoplastic matrices and possibly biodegradable ones. Moreover, in terms of life cycle analysis (LCA), it is recommendable that both matrix and fiber are obtained from by-products or even better waste from an industrial or agricultural process, so that their use may represent as such a reduction in the environmental impact of the whole process. Therefore, this chapter discusses first the opportunities offered and challenges encountered in the production of natural fiber composites, then concentrating on the possibilities to obtain a polymer matrix alternative to petrol-based ones, especially in the particular case of manufacturing biopolymers by using agrowaste as received or with limited structural transformations rather than simply as a monomer (e.g., dextrose) source for polymer synthesis.
The term “sea waste” generally refers to any solid, liquid, or gaseous material or substance that... more The term “sea waste” generally refers to any solid, liquid, or gaseous material or substance that is discarded, disposed of, or abandoned in the ocean, sea, or any other body of salty water, such as a lagoon, etc. This includes waste generated by human activities on land that makes its way into the ocean, as well as waste generated by ships and other vessels at sea. Examples of sea waste include plastic debris, chemicals and toxic substances, oil spills, sewage, and other forms of pollution. These pollutants can harm marine ecosystems, endanger marine life, and impact human health and wellbeing. Efforts are being made by governments, organizations, researchers, and individuals to reduce the amount of sea waste generated, and to clean up existing waste in the ocean. Less attention is usually paid to waste materials of natural origin as they are considered (sometimes wrongly) to be less critical; an example is the tons of organic and inorganic material of natural origin that wash up o...
Facta Universitatis, Series: Mechanical Engineering, 2019
This paper aims at investigating the influence of the addition of milled glass fibers upon quasi-... more This paper aims at investigating the influence of the addition of milled glass fibers upon quasi-static indentation (QSI) properties of glass/epoxy composite laminates. The QSI behavior was experimentally studied by evaluating indentation force, residual dent depth, energy absorbed and size of the damaged area for different indentation depths. Following the QSI tests, the filler-loaded glass/epoxy samples were subjected to three-point bending tests in order to measure residual flexural strength, and the results were compared with the baseline glass/epoxy samples. Both tests were performed with online acoustic emission monitoring in order to observe damage progression and characterize different fracture mechanisms associated with loading. The results show that the filler-loaded laminates exhibit a substantial improvement in the peak force and contact stiffness, with a reduced permanent damage both in terms of depth and of area, in comparison with the baseline ones. It is found that t...
AbstractThe production of bioplastics directly from wheat flour has been demonstrated to be relia... more AbstractThe production of bioplastics directly from wheat flour has been demonstrated to be reliable, but scarce knowledge is available on how flour characteristics may affect the performance of thermoplastic films. In this work, we first established the most suitable recipe and process for the production of extruded films and then we used eight single-cultivar wheat flours with different baking technological properties to assess how they affect the mechanical properties of thermoplastic films. The results have shown that flours from soft grain cultivars offered more rigid and deformable films than flours from hard grain cultivars. For similar hardness, the alveographic P/L ratio of the dough was inversely related to rigidity and directly related to deformability of plastic films, while the deformation energy of the dough (W) played a role only for great differences of it. The subsequent fabrication of blends between each of the flours that yielded the best film properties and polycaprolactone (PCL) at different proportions indicated that a wheat flour/PCL ratio (TWF/PCL) of 75/25 offered the most suitable films for further application. Our results are likely to be useful for improving the plasticization of flour, in that selection of wheat flours could be tailored on the properties desired for the bioplastic films.
A comparative assessment of three lignocellulosic fibres obtained from leaf, bast and fruit on th... more A comparative assessment of three lignocellulosic fibres obtained from leaf, bast and fruit on the mechanical and thermal properties of fully biodegradable composites has been performed.
The development of casein-based plastics is, together with starch-based one, an alternative to c... more The development of casein-based plastics is, together with starch-based one, an alternative to conventional ones, produced from hydrocarbons and their derivatives. Though dating back to late XIX century, under the principal name of galalith, its interest has been revived recently, also due to the efforts taken into implementation of circular economy, therefore to the waste-to-materials process. This recognizes the abundance of refuse derived from the dairy products sector, which allowed casein also entering the field of material tinkering for design. In a more industrial sense, a number of works exist in the last two decades focused on the revival of casein-based materials, mostly, yet not exclusively, in a formaldehyde-free version. These include a particular attention to the creation of packaging films, in some cases edible ones, which includes the experimentation on the effect of different plasticizers, such as polyols e.g., glycerol and sorbitol, and blending with starch or pectins. Other applications are being furthermore explored, which include biomedical use of casein films especially as wound dressing, the use of casein in the production of fibers, for textile and antibacterial purposes. In general terms, studies on casein materials are aimed at serving to the replacement of oil-based plastics, or as the matrix for natural fiber composites.
Most recently, there has been an increasing interest for the production of laminates for semi-str... more Most recently, there has been an increasing interest for the production of laminates for semi-structural applications using sustainable materials. In this field, a possible option is the use of composites including ligno-cellulosic fibers, which are normally obtained as by-products from the textile industry, therefore mainly in the form of fabric or mats. Despite a reasonably large amount of studies on thermosetting composites reinforced with vegetable fibers also exist, in the view to replace fiberglass e.g., in the automotive industry, it is clear on the other side that the evolution of natural fiber composites has a much stronger drive towards the use of thermoplastic matrices and possibly biodegradable ones. Moreover, in terms of life cycle analysis (LCA), it is recommendable that both matrix and fiber are obtained from by-products or even better waste from an industrial or agricultural process, so that their use may represent as such a reduction in the environmental impact of the whole process. Therefore, this chapter discusses first the opportunities offered and challenges encountered in the production of natural fiber composites, then concentrating on the possibilities to obtain a polymer matrix alternative to petrol-based ones, especially in the particular case of manufacturing biopolymers by using agrowaste as received or with limited structural transformations rather than simply as a monomer (e.g., dextrose) source for polymer synthesis.
The term “sea waste” generally refers to any solid, liquid, or gaseous material or substance that... more The term “sea waste” generally refers to any solid, liquid, or gaseous material or substance that is discarded, disposed of, or abandoned in the ocean, sea, or any other body of salty water, such as a lagoon, etc. This includes waste generated by human activities on land that makes its way into the ocean, as well as waste generated by ships and other vessels at sea. Examples of sea waste include plastic debris, chemicals and toxic substances, oil spills, sewage, and other forms of pollution. These pollutants can harm marine ecosystems, endanger marine life, and impact human health and wellbeing. Efforts are being made by governments, organizations, researchers, and individuals to reduce the amount of sea waste generated, and to clean up existing waste in the ocean. Less attention is usually paid to waste materials of natural origin as they are considered (sometimes wrongly) to be less critical; an example is the tons of organic and inorganic material of natural origin that wash up o...
Facta Universitatis, Series: Mechanical Engineering, 2019
This paper aims at investigating the influence of the addition of milled glass fibers upon quasi-... more This paper aims at investigating the influence of the addition of milled glass fibers upon quasi-static indentation (QSI) properties of glass/epoxy composite laminates. The QSI behavior was experimentally studied by evaluating indentation force, residual dent depth, energy absorbed and size of the damaged area for different indentation depths. Following the QSI tests, the filler-loaded glass/epoxy samples were subjected to three-point bending tests in order to measure residual flexural strength, and the results were compared with the baseline glass/epoxy samples. Both tests were performed with online acoustic emission monitoring in order to observe damage progression and characterize different fracture mechanisms associated with loading. The results show that the filler-loaded laminates exhibit a substantial improvement in the peak force and contact stiffness, with a reduced permanent damage both in terms of depth and of area, in comparison with the baseline ones. It is found that t...
AbstractThe production of bioplastics directly from wheat flour has been demonstrated to be relia... more AbstractThe production of bioplastics directly from wheat flour has been demonstrated to be reliable, but scarce knowledge is available on how flour characteristics may affect the performance of thermoplastic films. In this work, we first established the most suitable recipe and process for the production of extruded films and then we used eight single-cultivar wheat flours with different baking technological properties to assess how they affect the mechanical properties of thermoplastic films. The results have shown that flours from soft grain cultivars offered more rigid and deformable films than flours from hard grain cultivars. For similar hardness, the alveographic P/L ratio of the dough was inversely related to rigidity and directly related to deformability of plastic films, while the deformation energy of the dough (W) played a role only for great differences of it. The subsequent fabrication of blends between each of the flours that yielded the best film properties and polycaprolactone (PCL) at different proportions indicated that a wheat flour/PCL ratio (TWF/PCL) of 75/25 offered the most suitable films for further application. Our results are likely to be useful for improving the plasticization of flour, in that selection of wheat flours could be tailored on the properties desired for the bioplastic films.
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