Development of Boron-Containing Acrylic Resins

Turkey's boron reserves, the world's largest, make boron and its derivatives critically important to the country. In recent years, expanding the application areas of boron and boron derivatives across different industries and obtaining high-value-added products have become paramount. Boron is the 51st most abundant element in the Earth's crust. It occurs in the form of borates and boron silicates at concentrations of approximately 3 mg/kg. Its melting point is approximately 2300°C. It is an element in Group IIIA of the periodic table and exhibits very high affinity with carbon and silicon elements, and very high affinity with oxygen. The Earth's crust contains two stable isotopes of boron, 10B and 11B, with isotopic abundances of 19.10–20.31% and 79.69–80.90%, respectively. The abundance of boron isotopes in the crust varies from region to region. For example, in known boron deposits, the abundance of 10B is low in California, USA, but high in Turkey [1-3]. The chemical properties of elemental boron depend on its morphology and particle size. Amorphous boron with particle sizes smaller than 1 micrometer is reactive, sometimes rapidly so, while crystalline boron is less reactive. Boron reacts with water at high temperatures to produce boric acid and other byproducts. Reactions with mineral acids can be slow or explosive depending on concentration and temperature. Boric acid is the most commonly used boron derivative [4].

Global Boron Production

Analysis of global boron ore production over the years shows that most production occurs in two countries. In 1970, 66.4% of global production was from the United States and 15.9% from Turkey, with the remainder from other countries at approximately 17.7% (Figure 1) [5]. In 2012, actual global boron production was approximately 4 million tons (equivalent to 1.9 million tons of B2O3 (boron trioxide)). In the regional distribution of actual boron production on a B2O3 basis, Turkey ranks first with a 47.2% share, followed by the USA with 27.6%, South America with 15.8%, and Asia with 9.4% (Figure 2) [6]. [caption id="attachment_144428" align="aligncenter"] Figure 1. Distribution of global boron reserves [6][/caption][caption id="attachment_144429" align="aligncenter"] Figure 2. Global actual boron production [6][/caption] 

Applications of Boron Chemicals

Boron minerals and boron products are used in glass, ceramics, detergents, pharmaceuticals and chemical industries, refractory material manufacturing, agriculture, metallurgy, energy storage, automotive (airbags, hydraulic brakes, etc.), water treatment, pigments and desiccants, and nuclear applications. They are commonly used as resin additives and flame retardant chemicals. On the other hand, research exists showing that boric acid and its derivatives, particularly, are used as monomers in the development of many polymers, especially acrylic polymers [7,8]. [caption id="attachment_144430" align="aligncenter"] Figure 3. Chemical structure of boron acrylate monomer [7][/caption]    References [1] Özkan Ş. G., Çebi H., Delice S., Doğan M., Properties and mining of boron minerals, [2] Industrial Raw Materials Symposium İzmir, Pages 224-228, 1997. [3] Özkan S. G., Lyday P. A., Physical and chemical treatment of boron ores, SME's Annual Meeting, Denver, Preprint 95-186, 1995. [4] Ertuğrul E., Boron and Thorium Mining Sector, Sectoral Research, Turkey Development Bank A.Ş. Research Department, Ankara, 2004. [5] Elçiçek, H., Dissolution kinetics and optimization of ulexite ore under carbon dioxide pressure in aqueous medium, Master's Thesis, Atatürk University, Institute of Science, Erzurum, 2012. [6] BOREN-National Boron Research Institute 2016, [online], http://www.boren.gov.tr/tr/bor/bor-elementi. [7] Çanak, Çakır and İ. Ersin Serhatlı. "Synthesis and Characterization of Boron Acrylate–Styrene Copolymers." (2015). [8] Tuba Çakır Çanak, Kübra Kaya, I.Ersin Serhatlı, Boron containing UV-curable epoxy acrylate coatings, Progress in Organic Coatings, Volume 77, Issue 11, 2014, Pages 1911-1918.       Dr. Cemil Dizman Research and Development Director İzel Kimya   Levent Babayiğit Research and Development Researcher İzel Kimya