Materials The gluten solution New TPVs derived from wheat gluten By Karen Laird While gluten has got a lot of bad press over the past few years, there is still good news to report. Gluten, it turns out, can actually serve as the basis for a new type of biobased plastic material, say scientists at the KU Leuven in Belgium. These researchers are working on the development of a new type of thermoplastic vulcanisate – based on gluten. But what is gluten? Very simply put, is the seed storage protein in mature cereal seeds. More specifically, it is a protein composite, meaning it is a substance made up of several different proteins, in this case gliadin and a glutenin. The cross-linking of gliadin molecules and glutenin molecules creates the primary properties associated with gluten. According to Lien Telen, a postdoctoral researcher at KU Leuven who has spent the past five years exploring the the use of wheat gluten to produce thermoplastic elastomers, there are a number of aspects that make gluten an attractive starting point for novel biobased materials. In the first place, there is a lot of it: as a co-product of industrial gluten-starch separation or bioethanol production, gluten is available in Europe in quantities of up to 1 million tonnes on an annual basis. Only part of this gluten is used as a high-value bakery ingredient, while the excess is mostly used in animal feed. Secondly, unlike most other proteinaceous resources, gluten contains high molar mass constituents and unique network forming properties, which means it can readily be converted into a variety of biobased materials. The development that has received the most attention of the gluten team at KU Leuven, said Telen, has been the glutenbased TPVs (TPV stands for thermoplastic vulcanizates). These new materials are colorable and can be processed on conventional processing equipment. Unlike the olefin-based rubbers in conventional TPVs, wheat gluten intrinsically crosslinks under the influence of heat, eliminating the need for an additional chemical crosslinker. Gluten-based TPVs combine the typical properties and functional performance of rubbers with the melt processability of thermoplastic polymers, resulting in recyclable materials. Telen explains: “The gluten TPV consists of (non-recyclable) crosslinked gluten particles within a thermoplastic matrix. The main advantage of these TPVs is that they have elastomeric characteristics at room temperature combined with the melt processability of thermoplastic materials. The rubber particles are very small (a few µm) and will flow in the melt of the thermoplastic matrix making the entire material recyclable using standard thermoplastic polymer processing equipment such as extrusion and injection molding.” The gluten team is also working on improving the properties of the new TPVs, which, said Telen, “fall short on water-resistance, oil and chemical resistance and operational temperature range”. Yet what also sets gluten-based TPVs apart is the possibility of combining elastomeric behavior and biodegradability in a single material, a combination not seen in conventional oil-based TPVs. Depending on the thermoplastic component, the gluten TPV’s can be designed to be fully biodegradable. TPVs with a polyethylene or polyamide matrix are not completely biodegradable, as the matrix remains intact, making them unsuitable for composting. “However, completely biodegradable and (home) compostable TPVs have also been developed using a biodegradable and (home) compostable matrix,” said Telen. Applications for these materials could include indoor soft touch materials, or functional biodegradation applications in the agricultural and horticultural sectors. Next to gluten-based TPVs, the researchers at KU Leuven are looking at other materials as well. “In the absence of a plasticizer, the heat induced crosslinking results in a glassy, rigid material with material properties comparable to Polystyrene (PS)”, said Telen. “Gluten composites: rigid gluten bioplastic reinforced with flax fibers are another focus. Research on these materials is ongoing and very promising.” http://chem.kuleuven.be 60 – 80 % biobased non biodegradable 100 % biobased biodegradable anaerobic TPV 1 2 3 4 Tensile modulus (MPa) 333 197 265 494 Tensile elongation (%) 247 240 120 18 Tensile strength (MPa) 16 12 9 12 Shore D hardness 42 48 43 51 Melting temperature (°C) 129 118 125 140 Crystallization temperature (°C) 113 60 50 85 18 bioplastics MAGAZINE [01/16] Vol. 11
Market study on Bio-based Building Blocks and Polymers in the World Capacities, Production and Applications: Status Quo and Trends towards 2020 Bio-based polymers: Will the positive growth trend continue? Bio-based polymers: Worldwide production capacity will triple from 5.7 million tonnes in 2014 to nearly 17 million tonnes in 2020. The data show a 10% growth rate from 2012 to 2013 and even 11% from 2013 to 2014. However, growth rate is expected to decrease in 2015. Consequence of the low oil price? million t/a Bio-based polymers: Evolution of worldwide production capacities from 2011 to 2020 20 actual data forecast The new third edition of the well-known 500 page-market study and trend reports on “Bio-based Building Blocks and Polymers in the World – Capacities, Production and Applications: Status Quo and Trends Towards 2020” is available by now. It includes consistent data from the year 2012 to the latest data of 2014 and the recently published data from European Bioplastics, the association representing the interests of Europe’s bioplastics industry. Bio-based drop-in PET and the new polymer PHA show the fastest rates of market growth. Europe looses considerable shares in total production to Asia. The bio-based polymer turnover was about € 11 billion worldwide in 2014 compared to € 10 billion in 2013. http://bio-based.eu/markets © 15 10 5 2011 -Institut.eu | 2015 2% of total polymer capacity, €11 billion turnover 2012 Epoxies PE 2013 PUR PBS 2014 CA PBAT 2015 PET PA 2016 PTT PHA 2017 PEF 2018 Starch Blends EPDM PLA 2019 2020 Full study available at www.bio-based.eu/markets The nova-Institute carried out this study in collaboration with renowned international experts from the field of bio-based building blocks and polymers. The study investigates every kind of bio-based polymer and, for the second time, several major building blocks produced around the world. What makes this report unique? ■ The 500 page-market study contains over 200 tables and figures, 96 company profiles and 11 exclusive trend reports written by international experts. ■ These market data on bio-based building blocks and polymers are the main source of the European Bioplastics market data. ■ In addition to market data, the report offers a complete and in-depth overview of the biobased economy, from policy to standards & norms, from brand strategies to environmental assessment and many more. ■ A comprehensive short version (24 pages) is available for free at http://bio-based.eu/markets To whom is the report addressed? ■ The whole polymer value chain: agro-industry, feedstock suppliers, chemical industry (petro-based and bio-based), global consumer industries and brands owners ■ Investors ■ Associations and decision makers Content of the full report This 500 page-report presents the findings of nova-Institute’s market study, which is made up of three parts: “market data”, “trend reports” and “company profiles” and contains over 200 tables and figures. The “market data” section presents market data about total production capacities and the main application fields for selected bio-based polymers worldwide (status quo in 2011, 2013 and 2014, trends and investments towards 2020). This part not only covers bio-based polymers, but also investigates the current biobased building block platforms. The “trend reports” section contains a total of eleven independent articles by leading experts Order the full report The full report can be ordered for 3,000 € plus VAT and the short version of the report can be downloaded for free at: www.bio-based.eu/markets Contact Dipl.-Ing. Florence Aeschelmann +49 (0) 22 33 / 48 14-48 email@example.com in the field of bio-based polymers. These trend reports cover in detail every important trend in the worldwide bio-based building block and polymer market. The final “company profiles” section includes 96 company profiles with specific data including locations, bio-based building blocks and polymers, feedstocks and production capacities (actual data for 2011, 2013 and 2014 and forecasts for 2020). The profiles also encompass basic information on the companies (joint ventures, partnerships, technology and bio-based products). A company index by biobased building blocks and polymers, with list of acronyms, follows.