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Microalgae as a Source of Sustainability
Published in Pau Loke Show, Wai Siong Chai, Tau Chuan Ling, Microalgae for Environmental Biotechnology, 2023
Pik Han Chong, Jian Hong Tan, Joshua Troop
Plastic is one of the greatest human-created polymers and materials. However, most of the plastic we use in the modern day is made synthetically with fossil fuels (Gilbert 2017). Fossil-fuel-based synthetic plastic takes too long to degrade and, coupled with massive global production and inability to dispose of them caused plastics to pollute our environment. However, we cannot exactly remove plastics entirely out of human modern life. Plastics made the development of electronic products such as computers and smartphones possible. Plastics play an equally important role in various industries including fast fashion, automotive, courier, and food today (Haefely 1947; Stauber 2007; Kirwan, Plant, and Strawbridge 2011; Pacheco-Torgal and Jalali 2012; Rabnawaz et al. 2017; Niinimäki et al. 2020). Biodegradable plastics can be made of biological raw materials or petroleum, which can be decomposed by living organisms. As biodegradable plastics are made from biological raw materials, it also means they are renewable. However, to prevent food scarcity, using food-based plant material is out of the question. Besides, growing plants for biodegradable bioplastics can cause pollution from fertilizers and divert the aim of land use for food production (Tabone et al. 2010). Thus, this is where microalgae could play a huge role as a new source of raw materials to produce plastics and other materials. Chlamydomonas reinhardtii can produce starch and triacylglycerol bioplastic beads, without extraction and purification that can withstand compressive stress to 1.7 megapascals (Kato 2019; Mathiot et al. 2019).
Sustainable Polymers for Additive Manufacturing
Published in Antonio Paesano, Handbook of Sustainable Polymers for Additive Manufacturing, 2022
Based on a definition of degradation (Whittington 1978), a polymer or plastic material is degradable if it undergoes a damaging change in its chemical structure, physical properties or appearance caused by exposure to heat, light, oxygen, or weathering. According to ASTM D5488-94d and CEN EN 13432, biodegradable means “capable of undergoing decomposition into carbon dioxide, methane, water, inorganic compounds, or biomass in which the predominant mechanism is the enzymatic action of micro-organisms.” A biodegradable plastic is “a degradable plastic in which the degradation results from the action of naturally occurring microorganisms such as bacteria, fungi, and algae” (ASTM D6400-19). The rate of biodegradation is affected by various factors, such as the medium of biodegradation, its temperature and humidity, and chemical features of the degrading polymer, such as composition and MW. Biodegradable polymers are cellulose, chitin, starch, PHAs, PCL, and collagen. Not all biobased polymers are biodegradable. F.e. PET is biobased and not biodegradable. Some SPs are biodegradable, and other SPs do not biodegrade in landfill, because the amount of heat and/or oxygen is not adequate for these plastics to break down. Further information on biodegradable polymers is found in Averous and Pollet (2012). Polyvinyl alcohol (PVA) is a synthetic polymer that is water soluble.
Microbial Mediated Biodegradation of Plastic Waste
Published in Amitava Rakshit, Manoj Parihar, Binoy Sarkar, Harikesh B. Singh, Leonardo Fernandes Fraceto, Bioremediation Science From Theory to Practice, 2021
Rajendra Prasad Meena, Sourav Ghosh, Surendra Singh Jatav, Manoj Kumar Chitara, Dinesh Jinger, Kamini Gautam, Hanuman Ram, Hanuman Singh Jatav, Kiran Rana, Surajyoti Pradhan, Manoj Parihar
Based on biodegradability, the fossil-based and bio-based plastics can be classified into two groups such as non-biodegradable and biodegradable plastic (Table 1). Non-biodegradable plastics are high molecular weight derivative of hydrocarbon and petroleum compound with high stability and do not readily enter into the degradation cycles of the biosphere (Vijaya and Reddy 2008, Ghosh et al. 2013), for example, polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyethylene (PE) and polyurethane (PUR) (Ahmed et al. 2018). Biodegradable plastics depend upon the degree of biodegradability and microbial assimilation (Wackett and Hershberger 2001). This process involves the degradation of complex polymer compound into smaller compounds in the presence of enzymes which are secreted by microorganisms (Artham and Doble 2008), for example, starch (Chattopadhyay et al. 2011), Polyhydroxyalkanoates (Shimao 2001), Polylactic acid (Ikada and Tsuji 2000), Polyethylene succinate (Hoang et al. 2007) and Polycaprolactone (Wu 2005). Biodegradable plastic is further classified into two categories, which is bio-based biodegradable plastic and fossil-based biodegradable plastic.
Plastic microbeads: small yet mighty concerning
Published in International Journal of Environmental Health Research, 2021
Shaima S. Miraj, Naima Parveen, Haya S. Zedan
Biodegradable plastics are generally composites of synthetic polymers and vegetable oils, starch or other specialist chemicals designed to accelerate degradation. If they are disposed off properly, they will decompose in industrial composting plants under well-aerated conditions. Exposure to sunlight can result in photo degradation of plastics over a prolonged period of time; ultraviolet radiation causes oxidation of polymer matrix results in bond cleavage. But, such degradation may result in additives leaching out of the plastics, which are added to enhance durability of the plastics and make it corrosion resistance, (Moore 2008; Talsness et al. 2009; Andrady et al. 2019).
Biodegradation of Moringa oleifera’s polymer blends
Published in Environmental Technology, 2019
Cristiane Medina Finzi-Quintão, Kátia Monteiro Novack, Ana Cláudia Bernardes-Silva, Thais D. Silva, Lucas E. S. Moreira, Luiza E. M. Braga
All organic compost may be degrading with appropriate environmental conditions (Microbial infallibility theory) [3]. The use of pro-degradant additives based in metals such as manganese, iron and zinc on conventional polymers can improve their degradation capacity. Additives promote the acceleration of oxidation of polymer catalysed by the presence of oxygen and light (oxodegradation process) [4–6]. According to the literature, a biodegradable plastic is a polymer that degrades due to the action of microorganisms such as bacteria, fungi and algae [7–9].
Reusing plastic waste in the production of bricks and paving blocks: a review
Published in European Journal of Environmental and Civil Engineering, 2022
Turkeswari Uvarajan, Paran Gani, Ng Chuck Chuan, Nur Hanis Zulkernain
Besides, searching an alternative plan for regular plastics by using biodegradable plastics could be another feasible option. However, the cost of using the existing raw material to produce biodegradable plastics is more expensive than the petroleum-based plastics (Kabir et al., 2020; Oever et al., 2017).