Bio-Based Plastics as an Alternative to Petroleum-Derived Plastic Use

Bio-Based Plastics as an Alternative to Petroleum-Derived Plastic Use Environmentally Friendly Felt-Tip Pen Production Using Starch-Based Bio-Based Polypropylene and Its Effect on Carbon Emissions

Abstract

Plastics have become an indispensable part of our daily lives and appear in virtually every sector due to their ease of processing, low cost, lightness, flexibility and other advantages. For these reasons, they are also an essential component of the stationery industry. Despite their many advantages, plastics synthesized from petroleum and petroleum sources can persist in nature for long periods without decomposing and release carbon into the atmosphere, causing environmental pollution. These conditions pose a threat to the ecosystem. Additionally, factors such as population growth, petroleum being a depleting resource, limited petroleum reserves, and environmental pollution caused by plastics reaching alarming levels have made the search for low-cost sustainable alternative sources a necessity. Today, people have become aware of how the consequences of excessive consumption and unsustainable practices will severely affect our near future and have begun to adopt conscious approaches. Over the last 20 years, based on the need to rely on sustainable raw materials, reduce dependence on fossil sources and lower carbon emissions, renewable polymers that replace traditional petroleum-based plastics—that is, bio-based polymer plastic materials—have become the focus of many materials scientists [1]. Bioplastics are preferred over 100% petroleum-based plastics because they emit less CO2 to the environment and are obtained through the use of agricultural products as raw materials [2]. In this study, the application of bioplastics—which are used in many fields from home textiles to the stationery industry, from the automotive industry to food services [3]—to stationery sector products was targeted, and the first steps were taken with bio-based plastic use as an alternative to petroleum-derived plastic use in felt-tip pens.

1. Introduction

Conventionally used plastics are obtained by processing raw materials derived from fossil sources such as petroleum, natural gas and coal. The indispensable use of plastic in modern life has significantly increased waste accumulation. Waste disposal and recycling have become a primary concern in waste management. In addition, most plastic waste accumulates in landfills, soil, oceans and water bodies, thereby creating major hazards for plants, terrestrial and aquatic animals, and humans. Due to the problems caused by conventional plastics, in recent years the production of bioplastics and biodegradable plastics and the use of these bioplastics instead of petroleum-derived plastics have gained importance. Polymeric material is considered bioplastic when it is made from bio-based or biodegradable, renewable materials. The distinction between conventional and bioplastics is detailed in the table below [4]. Greenhouse gases are gaseous compounds that emit ultraviolet radiation within a specific thermal infrared range. The major greenhouse gases in all layers of the atmosphere are H2O, CO2, CH4, O3 and N2O. Greenhouse gases maintain high temperatures in the lower atmosphere, allowing less heat to escape back into space—in other words, they trap heat. This subsequently causes the greenhouse effect and global warming. High dependence on petroleum-derived fossil fuels for energy production and other industrial activities increases the emission of greenhouse gases [5]. In the last 150 years, human activities have been responsible for nearly all of the increase in greenhouse gases in the atmosphere [6]. Among petroleum-derived plastics, polypropylene use has by far the largest volume worldwide. According to data in Ecoinvent database version 3.6, the production of 1 kg of polypropylene granules in Europe generates 1.91 kg CO2eq/kg of greenhouse gas emissions [7]. Biodegradation is a chemical process in which microorganisms present in the environment convert materials into natural substances such as water, carbon dioxide and compost without requiring artificial additives. Biopolymers have attracted major interest in the biotechnology field because of important advantages such as replacing fossil-based polymers while also reducing the toxic effects that fossil-based polymers have had on the environment. The raw materials needed for bioplastic material production are found in abundance in waste and by-products of the food and livestock industries. These wastes are inexpensive and renewable sources. Bioplastics may contain starch, cellulose, proteins, lignin, chitosan, polylactic acid (PLA) and polyhydroxyalkanoates (PHA) and polyhydroxybutyrates (PHB). Starch currently leads among the most commonly used biodegradable polymers. Starch found in crystals in vegetables, such as potatoes and corn, cannot be used directly in plastic material production because of its easy solubility in water. For this purpose, during plastic production from starch, non-degradable synthetic polymers such as polyethylene, polypropylene and polystyrene are typically used along with plasticizers such as water, glycerin and sorbitol, and starch's molecular structure is broken down under specific conditions by heating. The material obtained as a result of this process, known as gelatinization, is known as thermoplastic starch (TPS). The reason for adding starch to polymers is that certain microorganisms in nature use starch, a glucose polymer, as a nutrient and secrete enzymes to break down the plastic in order to reach the starch within it [8]. Vinçotte, an inspection and certification body in Belgium, launched the OK bio-based certification program in September 2009 to provide companies with an independent assessment of their products' renewability. The OK bio-based certification scheme, which is integrated into TÜV AUSTRIA Group, uses a star system to indicate a product's bio-based content. A bio-based product with one star contains between 20% and 40% bio-based carbon content, while a product certified with four stars contains more than 80% bio-based carbon content. One Star ✸ 20% ≤ Biobased Carbon Content (BCC) < 40% Two Stars ✸ ✸ 40% ≤ BCC < 60% Three Stars ✸ ✸ ✸ 60% ≤ BCC < 80% Four Stars ✸ ✸ ✸ ✸ 80% ≤ BCC [9]. The raw material used in felt-tip pens qualified to receive one star from TÜV Austria based on its bio-based carbon content according to EN 16640 test methodology [10]. In this study, instead of the felt-tip pen barrel traditionally produced using 100% petroleum-derived polypropylene (PP), a felt-tip pen barrel was produced using a thermoplastic starch-containing PP compound certified with OK biobased 1 star by TÜV Austria.

2. Materials and Method

Prior to thermoplastic starch-based PP production, the material was kept in an oven at 70±2°C for 2 hours to remove moisture before use. The dried granules were fed from the feeder unit, processed in an injection molding machine under appropriate temperature and pressure, and formed into felt-tip pen shape in a 16-cavity mold. Test plates were prepared in accordance with standards for conducting mechanical analysis and testing. Tensile tests were applied to the prepared test plates, and tensile strength, elongation at break, modulus of elasticity, flexural strength and flexural modulus tests were performed according to ISO 527-2, density testing according to ISO 1183, hardness value according to ISO 868, and melt flow index according to ISO 1133. The physical and mechanical test results for standard 100% petroleum-derived PP and the Ok Biobased 1 star certified thermoplastic starch-containing PP granules used in bio-based felt-tip pen production are as follows. When the measured mechanical and physical properties of the existing product and those produced with bio-based materials were evaluated, the newly developed product met our internal control standards.

3. Conclusion

High volumes of commercial plastics are used in the stationery industry. Within the scope of the European Green Deal and Turkey's Climate Plan; with the aims of combating climate change, contributing to a sustainable economy and reducing environmental pollution, Adel Kalemcilik implemented the first bio-based felt-tip pen production by using bio-based polymers in felt-tip pens and brought it to market. The bio-based carbon-containing raw material used in felt-tip pens contains 20-40% thermoplastic starch according to its certification. Since one of the base materials in the product containing thermoplastic starch is polypropylene and polypropylene has high fluidity, it enables easy processing of the product in the injection molding machine, and its mechanical properties met the desired standards in quality control analyses (Table 1). By using starch-based material certified with Ok biobased 1 star in this product, with this developed bio-based felt-tip pen series we eliminated the use of 1,440 kg of commercial polypropylene in one year. By reducing commercial polypropylene use by 1,440 kg and calculating using Ecoinvent database version 3.6 data, we eliminated a total of 2,750.4 CO2eq/kg emissions. Using the Greenhouse Gas Equivalencies Calculator program on the EPA website, the 2,750.4 CO2eq/kg emissions reduction we achieved is equivalent to: 70,508 miles driven by an average gasoline-powered passenger vehicle, 3,095 gallons of gasoline, 2,702 gallons of diesel fuel consumption, burning 30,809 kilograms of coal, one year of energy use by 3.5 homes, one year of electricity consumption by 5.4 homes, 63.6 barrels of oil consumption, charging 3,345,659 smartphones [11]. In recent years, as we have begun to see very clearly the consequences of the global climate crisis (increasing forest fires, floods, hurricanes, melting glaciers, etc.); the issue of how to reduce the dangerous effects of plastic waste on human health and ecosystems has become one of the most discussed topics. Increasing environmental awareness has created public pressure for both the establishment of legal regulations and the environmental transformation of commercial activities [12]. In recent years, in many industries such as textiles, fashion, plastics, energy-intensive sectors and packaging, new solution paths have been sought in the use of innovative eco-friendly materials with the aim of minimizing harm to nature and the environment, and substantial and rapid developments have been observed. This work has been pioneering in Turkey's stationery sector in the use of environmentally friendly sustainable materials in the bio-based plastic products group. Felt-tip pens produced using bio-based compounds will have less toxic impact when they reach nature due to the renewable raw materials they contain, and the amount of petrochemical-derived plastic left in the ecosystem and persisting in nature for very long periods, as well as the carbon emissions from these plastics, will decrease. Both to ensure that children develop environmental awareness from an early age and raise awareness, and with the goal of transforming polymeric stationery products in the stationery sector into more environmentally friendly products, we aim to expand this pilot project to more polymer-based stationery products. 4. References 1. Ozdamar, E. G., & Ates, Murat. (2018). Rethinking sustainability: A research on starch based bioplastic. Journal of Sustainable Construction Materials and Technologies,3(3), 249–260. 2. Gironi, F., & Piemonte, V. (2011). Bioplastics and Petroleum-based Plastics: Strengths and Weaknesses. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, s.1949-1959. 3. Grancarić, A. M., Jerković, I., & Tarbuk, A. (2013). Bioplastics in textiles. Polimeri: Časopis Za Plastiku İ Gumu, [Conference Paper: UDK 677.1/.5:678:620.1]. 34(1), 9–14. 4. Sonil Nanda, Biswa R. Patra, Ravi Patel, Jamie Bakos, Ajay K. Dalai, Innovations in applications and prospects of bioplastics and biopolymers: a review. Environmental Chemistry Letters (2022) 20:379–395. 5. Advances in Carbon Capture, "Chapter 1 CO2 emission sources, greenhouse gases and the global warming effect" Kelvin O. Yoro, Michael O. Daramola, 2020. 6. https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions 7. Greenhouse gas emissions and natural capital implications of plastics (including biobased plastics) Eionet Report – ETC/ WMGE 2021/3 8. Akdoğan Eker, A. 2009. Türkiye'de Plastik Hammadde Üretimi ve İthalatı. www.yildiz.edu.tr/~akdogan/lessons/plastikmalzeme/Belgeler/Biyoplastikler.pdf (Erişim: 17/03/2017). 9. https://en.tuv.at/ok-biobased-en/ 10. https://en.tuv.at/certifications/product-certificate/ 11. https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator#results 12. Sürdürülebilir Tasarım Yaklaşımı Açısından Biyoplastiklerin İncelenmesi, Dr. Öğr. Esin Düzakın https://doi.org/10.20488/sanattasarim. 970913 Geliş Tarihi: 26.06.2020, Kabul Tarihi: 10.12.2020. Elif Öz Çetin - Research and Development Specialist Master of Chemistry Engineer Adel Kalemcilik Ticaret ve Sanayi A.Ş. Dr. Fatma Seda Güreli Feridun - Product Safety and Regulation Specialist Doctor of Chemistry Adel Kalemcilik Ticaret ve Sanayi A.Ş.