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issue 03/2021

Highlights: Bottles / Blow Moulding Joining Bioplastics Basics: Carbon Capture

Materials Microplastic:

Materials Microplastic: solving the problem without harming our planet Acoustic and thermal characterization of a novel sustainable material incorporating recycled microplastic waste I n 2017, the UN declared the presence of 51 trillion microplastic particles in the Earth’s seas: “500 times more numerous than all the stars in our galaxy.” A product invented and patented by Marco Caniato, a researcher and lecturer at the Free University of Bozen- Bolzano (Italy), has proved extremely promising in the battle against the environmental dispersion of microplastics. Secondary microplastics, i.e., plastic fragments of less than 5 mm in size resulting from the use and abandonment of objects such as plastic bags or bottles, account for around 68–81 % of the microplastics in the oceans (source: European Parliament). Worldwide, the seas have been described as one of the most polluted areas by micro and macroplastics. As a result, the treatment and life-cycle management of plastics has become a huge problem whose lack of solution threatens marine biodiversity and the survival of many fish species. Not to mention the fact that the dangers to humans of these tiny plastic fragments entering the food chain are not yet known. The idea by Marco Caniato was born five years ago. A very large industrial company asked for recycling solutions for carbon fibre, which is notoriously difficult to recycle. It was a composite material, made of plastics and carbon fibres, strongly bonded together. A material next to impossible to recycle using traditional approaches. A chemical procedure is available but expensive and polluting. “Thus, the aim was to obtain something solving the problem without harming our planet with more waste,” underlines Marco Caniato. The chemical pathway was not an option – another approach was needed. Marco’s background is in materials science and engineering focusing on acoustic and thermal issues, so a new sustainable material, which could also be used as a thermal and acoustic insulator, was designed namely a foam. For two months, a process to create foam without using chemicals was sought. “Unfortunately, literature and many colleagues just said to me that this was impossible,” Marco remembers. “But as Einstein said, Everyone knew it was impossible until a fool who didn’t know came along and did it.” Marco Caniato was that fool and designed the process together with Andrea Travan, who was working on new biobased materials for human purposes (such as bones or organs), using properties of biomaterials. In a week, the first sample was realized, recycling carbon fibre. Then, many studies were carried out on the new foam in order to optimize its properties, shape, mechanical features, etc. Successfully, glass powder, carbon fibre, fibreglass, and other composite materials were recycled. The next step was to use microplastic, almost a natural development. The used biopolymer comes from algae. “I tried many kinds of biopolymers but the most economic and optimized is the alginate. It is extracted from a particular sea algae,” explains Caniato at the Faculty of Science and Technology in Bozen-Bolzano. The alginate is relatively cheap as it is used in many applications like the food industry and pharmaceutics. The usage in these fields makes it obvious that it is not harmful. We eat it when making puddings, hot chocolate, sweets etc.. The foam application fields vary from construction, to automotive, to industrial applications, to naval industries. “Basically, where we can have a problem of thermal and/or acoustic insulation, the foam can be used,” Marco Caniato sums up, as the properties of this biofoam were repeatedly tested. With the help of his colleagues Giada Kyaw Oo D’Amore, Luca Cozzarini, Jan Kašpar, and Chiara Schmid from the University of Trieste (Italy), many different samples incorporating a diverse range of wastes were produced. The thermal and acoustics properties, mechanical characteristics, fire resistance, nano and microstructure influence were investigated in dedicated facilities, comprising Kundt’s tube, X-ray microtomography, SEM, airflow resistivity tube etc. With the help of Andrea Gasparella, the analytical models of the acoustic and thermal behaviours were derived. All of the above-described properties are comparable or better than traditional materials like rock wool. This biofoam presents paramount advantages: (i) It is not harmful to neither human (unlike rock wool, etc) nor the environment. It has an easy end-of-life solution as filler in other biofoams. (ii) Its production does not involve pollutants or petroleum derivatives or other rare elements – just sea algae (waste). The same water can be used in multiple production processes. (iii) The involved technologies are already available. No new costly machinery is needed. (iv) Both acoustic, thermal, mechanical, micro, and nano 50 bioplastics MAGAZINE [03/21] Vol. 16

Materials properties can be customized for the dedicated application by using biobased agents which modify the internal foam structure, suiting the desired requirement. AT/MT Find a more comprehensive scientific article at [1] [1] Caniato,M. et. Al.: Acoustic and thermal characterization of a novel sustainable material incorporating recycled microplastic waste; Sustainable Materials and Technologies Volume 28, July 2021; Avocado waste to reduce avocado waste When avocados are processed for use in food items, the amount of waste produced can account for more than 45 % of the total weight of the avocado. In order to make use of this waste and extend the shelf life of prepared products, Aimplas, the Plastics Technology Centre (Valencia, Spain), is developing the GUACAPACK Project, funded by the Valencian Innovation Agency (AVI) (Spain). The project is led by the company ITC Packaging and the Universidad de Alicante’s research group on Polymer and Nanomaterial Analysis (Nanobiopol-UA) (both Alicante, Spain) is also taking part. The project aims to develop a new biodegradable packaging system from renewable sources that also extends the shelf life of food (for example guacamole) by 15 %. This shall be achieved by using a label with oxygen-barrier function that prevents the oxidation of food, and on the incorporation of natural antioxidants extracted from the avocado itself, which also helps reduce the use of synthetic preservatives. To achieve this, starch from the avocado seed will be extracted and purified to obtain a film that can be used to make multilayer IML labels that have oxygen barrier properties and prevent the oxidation of food. In addition, the active components of waste avocado skin and flesh with a high antioxidant capacity will be obtained and used as an additive for PLA that will then be injection moulded to manufacture the packaging system. When food makes contact with this system, its shelf life will be extended by 15 %. This option provides an alternative to the use of synthetic additives, as well as a new, high value-added use for agrifood waste to obtain biodegradable packaging from renewable sources. The project is therefore fully aligned with circular economy criteria. This project will also help achieve the United Nations Sustainable Development Goals (SDGs), especially SDG 3 on Good Health and Well-Being, SDG 9 on Industry, Innovation and Infrastructure, and SDG 12 on Responsible Consumption and Production. AT | | Materials News bioplastics MAGAZINE [03/21] Vol. 16 51

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