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Issue 03/2017

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  • Bioplastics
  • Biobased
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Materials Bio-Epoxy

Materials Bio-Epoxy Resins from Plant oil INTRODUCTION Uncertainty in terms of price and unavailability of petroleum, in addition to global, political and institutional tendencies toward the principles of sustainable development, is urging the chemical industry towards a sustainable chemistry and particularly the use of renewable resources in order to synthesize biobased chemicals and products. There is an increasing demand for biobased, sustainable performance materials, where the emphasis is laid mainly on performance and endurance. Thus, fully biobased epoxy cross-linked polymers are nowadays a real target and also a great challenge for researchers. BIO-EPOXY RESIN Epoxy resins are widely used polymers due to their diverse industrial applications [1] requiring superior strength, excellent adhesion, good chemical resistance, and excellent performance at elevated temperatures due to which, they are used in coatings, electrical/electronic laminates, adhesives, flooring and paving applications, and high performance composites. Production of global epoxy thermosetting polymers is estimated to be 2 million tonnes in 2010 and is projected to reach 3.5 million tonnes by the year 2020. Conventional epoxy resins are low molecular weight pre-polymers or higher molecular weight polymers which normally contain at least two epoxide groups. They are formed by reacting epichlorohydrin with Bisphenol A (BPA) to form diglycidyl ethers of bisphenol A (commonly abbreviated as DGEBA or BADGE). In recent years concerns increased over the impact of Bisphenol A on the environment and human health. BPA is a xenoestrogen and may have feminizing effects even at nanogram levels. Environmental studies indicate that this organic compound interferes with nitrogen uptake in certain plants, namely legumes such as beans. Several studies have also found levels of Bisphenol A in municipal wastewater. In addition, it has been determined that Bisphenol A is harmful to marine life. The conventional epoxy resin has many adverse effects on the environment, human health and they increase concentration of carbon dioxide (a greenhouse gas) in atmosphere after thermal decomposition / incineration of epoxy resins (polymers). Bio-epoxy resins are low molecular weight biodegradable polymers which are synthesized from natural oils (vegetable oils). These resins are gaining much more importance because of their environmentally friendly nature, sustainability, green method of manufacture, excellent biodegradability, lower energy cost in manufacture and much lower carbon footprint. Bio-epoxy resins, usually obtained from plant oil raw materials are the most important thermosetting resins, which after cure, display excellent mechanical strength, good thermal, electrical, and chemical resistance, and fine adhesion to many substrates. In most of the cases, bio-epoxy resins also provide cost savings as compared to that of petroleumbased polymer products and they biodegrade in a limited period. These plant oil based polymers are environment friendly in many ways. They are for example biodegradable. The plants absorb carbon dioxide while growing reducing greenhouse gases. Among the various plant seed oils, nonedible oils have been used for the development of chemicals and polymers thus avoiding food vs. fuel predicament. Vegetable oil certainly is a future potential source of renewable materials [2]. Furthermore, vegetable oil contains triglycerides that can be used to make useful oleochemicals and polymers. The present system has been developed from non-edible epoxydised vegetable oil and plant source based hardner (both are derived from renewable resource) which forms the total system derived from 100% biobased. APPLICATIONS The most important aspect of the products described here is that under suitable conditions it undergoes complete biodegradation within 90 days. The bio epoxy resin is biocompatable and non-toxic in nature. For testing purpose elastomeric sheets prepared from the product has been subjected to biodegradation under cow dung biocompost and under bacterial granules (3-5 mm) obtained from bacterial consortia in liquid nutrient media where polymer samples were suspended in it. The progress of biodegradation was monitored using SEM micrographs and weight loss of polymer [3, 4]. A biodegradation test using ASTM D 5338 by the Indian certifying agency is under progress. Various industrially useful products ranging from soft to hard using fillers, additives and fibre composites can be derived from these polymers. Examples are printing ink, high gloss paint, lamination, Indian rakhi, deity Ganesha idol, thin flexible transparent film for packaging, various cast resin articles, like letters, play dolls, encapsulant for electronic circuit board and fibre based composite. A patented [5] two component bio-epoxy resin system developed by Swami Ramanand Teerth Marathwada University Nanded India has been under manufacture and marketed by Supreme Silicones Pune India. 30 bioplastics MAGAZINE [03/17] Vol. 12

Materials By: Omprakash Yemul Swami Ramanand Teerth Marathwada University, Nanded, India Omkar Waikar Supreme Silicones Pune, India Summary Bio-epoxy resin derived from vegetable oil promises one the most vital part of today’s world to move toward more sustainable life. Through several types of applications, bio-epoxy resin offer many substantial advantages over conventional petroleum based epoxy resin. Bio-epoxy resin provides excellent biodegradability. Potentially much lower carbon footprint is created compared with that with conventional epoxy resin. References [1] C. A. May, Epoxy resins-chemistry and technology, (1988) 2nd Ed. New York: Marcel Dekker [2] . Z. S. Petrovic, Polymers from biological oils. Contem. Mat-I, (2010); 1, 39-50. [3] Y.M. Kolekar, H.N. Nemade, V.L. Markad, S.S. Adav, M.S. Patole, K.M. Kodam, Decolourization and biodegradation of azo dye, reactive blue 59 by aerobic granules, Bioresour. Technol. 104 (2012) 818e822. [4] E. Ikada, Electron microscope observation of biodegradation of polymers, J. Environ. Polym. Degrad. 7 (4) (1999) 197e201 [5] O. S. Yemul, et. al. A process for the preparation of biodegradable polymeric materials from algae oil. Indian Patent IN283327 (2017). Bioepoxy resin based cast article, embedded circuit board and composite 0 day 50 days 0 day 50 days 0 day 50 days (A) (B) (C) Comparative images of Biodegradation stages of (A) Bisphenol A epoxy resin film, (B) Trimethylol Propane Triglycidyl Ether and (C) Bio-epoxy resin film bioplastics MAGAZINE [03/17] Vol. 12 31

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