Biomaterials & Biodevices
Patrick Jahn; Samuel Schabel
Abstract
Packaging is essential for the global transport and storage of goods. However, due to the widespread use of non-biodegradable raw materials, it is a topic of environmental discussions. Paper plays an important role in the packaging sector due to the sustainability of the material, its outstanding flexibility ...
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Packaging is essential for the global transport and storage of goods. However, due to the widespread use of non-biodegradable raw materials, it is a topic of environmental discussions. Paper plays an important role in the packaging sector due to the sustainability of the material, its outstanding flexibility and its high specific strength. But paper also has disadvantages. Paper does not possess wet strength and does not provide barrier properties. These disadvantages have so far been overcome by creating coated paper, paper laminates or through the addition of substances during production. An alternative solution could be All-Cellulose Composites (ACC), which are composites completely made of cellulosic materials.Within the scope of this research short process times will be tested to determine if it is possible to achieve an increase in wet strength and barrier effect sufficient for packaging application. In addition, it will be investigated whether moist paper can be converted into ACC and to what extent the moisture content influences the resulting properties. The papers that will be converted are produced from bleached kraft pulp fibres (NBSK) on a Rapid Köthen sheet former. The conversion to ACC takes place via an immersion process. NaOH-urea is used as the solvent system, which is cooled to -12.5 °C. The tests show that a treatment period of just a few seconds is sufficient to significantly improve tensile and wet strength. It still needs to be clarified for what kind of technical applications the barrier properties achieved so far are suitable.
Composite Materials
Rahul Dev Bairwan; Esam Bashir Yahya; Deepu Gopakumar; Abdul Khalil H.P.S.
Abstract
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is the most promising and appropriate microbial biopolymer as a replacement for conventional petroleum-based non-biodegradable polymers, due to its excellent biodegradability and biocompatibility. However, it has a few limitations that prevent it from ...
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Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is the most promising and appropriate microbial biopolymer as a replacement for conventional petroleum-based non-biodegradable polymers, due to its excellent biodegradability and biocompatibility. However, it has a few limitations that prevent it from being used commercially, including low mechanical strength, hydrophobicity, poor thermal and electrical properties, difficult processing, and high cost. Recent researches has shown that it is the most promising natural biopolymer, particularly for packaging. To use PHBV in biocomposites, methods of compensating for PHBV's shortcomings, such as adding fillers, more cost-effective and efficient production methods, or alternative PHBV sources, must be developed. Numerous researchers are looking into ways to improve characteristics and lower prices by developing biocomposites to address environmental safety concerns with PHBV, developing and discovering more affordable biological PHBV production methods, discovering new microbial strains or strain combinations, or developing less expensive PHBV extraction methods. The current review provides a detailed description of the studies conducted to improve the properties of PHBV as biocomposites by employing less expensive yet efficient reinforcements, particularly for food packaging applications. Furthermore, nanocellulose can be studied further as a PHBV biocomposites enhancement to improve properties and functionalities from various optimal sources in order to produce fully degradable bionanocomposites for sustainable packaging applications.
Gion A. Barandun; Donat Sch
Abstract
Fibre reinforced composite materials offer superior specific mechanical properties in reference to their weight. In the past years, composite materials such as carbon or glass reinforced plastics (CFRP or GFRP) are used increasingly in all sectors of transportation and for industrial or leisure products. ...
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Fibre reinforced composite materials offer superior specific mechanical properties in reference to their weight. In the past years, composite materials such as carbon or glass reinforced plastics (CFRP or GFRP) are used increasingly in all sectors of transportation and for industrial or leisure products. The composite consists of a load bearing fibre architecture, usually in the form of a continuous fabric architecture, and an embedding matrix, usually a thermoset such as epoxy. With regard to the energy efficiency and carbon footprint, due to their lightweight nature, these composite materials in general offer interesting properties, if applied in long-term operations. However, the raw materials used for the production of both typical fibre materials and thermoset resins are still based on crude oil, and the refining and processing up to the semi-finished good consume a significant amount of embodied energy. In this study, composites made of glass or flax fibres and resin systems based on condensed tannin and furfuryl alcohol, both extracted or derived from plant tissues, were manufactured using vacuum infusion (VI) and resin transfer moulding (RTM) processes. The results show that mechanical properties close to common fiber/resin combinations like glass fiber and epoxy or phenolic resins can be reached by these materials.
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