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Issue 06/2017

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  • Bioplastics
  • Biobased
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  • Biodegradable
  • Sustainable
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bioplasticsMAGAZINE_1706

Polyurethanes /

Polyurethanes / Elastomers Sugar for extra grip Kuraray unveils biobased elastomer Septon Bio Fig. 1: Getting a grip: The new copolymer Septon Bio from Kuraray displays high grip and non-slip properties on wet and dry surfaces. Kuraray Europe (Hattersheim, Germany) is unveiling Septon TM Bio, its new bio-based thermoplastic elastomer. The hydrogenated styrene farnesene block copolymer (HSFC) is the outcome of collaboration between specialty chemicals producer Kuraray and bio-science company Amyris (Emeryville, California, USA). Septon Bio can be used in a multitude of applications, needs only small quantities of plasticizer, and is particularly easy to process thanks to its special properties. Cycle handlebar grips have to provide a firm handhold, nonwoven fabrics have to be elastic, and sports shoes have to be effective in absorbing impact. Special thermoplastic elastomers (TPEs) make these properties possible. They are put to use in a variety of applications such as fibers, composite materials and coatings and have to be highly elastic, and tear- and heatresistant. International specialty chemicals manufacturer Kuraray has developed its Septon TPE series for this purpose. The hydrogenated styrene di- and triblock copolymers with their high flowability are easy to process and highly elastic and are used as the basic polymers for a broad variety of products and for polymer modification. Kuraray is now presenting Septon Bio, a TPE that is bio-based while exhibiting the wide-ranging benefits of the Septon series. Kuraray has developed the new Septon Bio TPE in cooperation with US bio-science company Amyris. The copolymer is based on beta-farnesene, a renewable monomer from Amyris derived from biological raw materials. “During fermentation, special strains of yeast convert sources of sugar such as sugarcane into betafarnesene,” explains Jan-Sebastian Weber, Marketing and Sales Manager at Kuraray. “The hydrogenated styrene farnesene block copolymer (HSFC) is then produced from the beta-farnesene.” After polymerization, the farnesene has a special chemical structure. More Flexible, More Elastic and Easier to Process than HSBC Thanks to its characteristic structure, HSFC has unique properties and hence distinct advantages over conventional hydrogenated styrene block copolymers (HSBC). HSFC Septon Bio has a lower viscosity than conventional styrene block copolymers and at the same time a high loss factor (tan delta) over a large temperature range. Septon Bio therefore shows much better flow behavior than comparable copolymers. In addition, Septon Bio has very good adhesive properties, again over a broad temperature range. The new copolymer is thus easy to process and suitable for numerous applications in a wide-range of sectors. • Septon Bio facilitates outstanding grip in wet and dry conditions. This makes the copolymer an excellent choice for sports and household articles, footwear and industrial applications. • Septon Bio is extra-elastic and features low tensile strength. In addition, it has an extremely low compression set and thus deforms very little even after long-term exposure to compression. This makes the copolymer highly compatible with such processes as melt-spinning for nonwoven fabrics and extrusion for elastic films. • Septon Bio can be released easily and without residues – ideal for use in protective films. • Its particularly high damping effect is exhibited over a broad temperature range. This makes Septon Bio the ideal raw material for products in which sound or vibration absorption is important, such as in sports shoes. • At the same time, HSFC Septon Bio is much less rigid than HSBC polymers. Consequently, less plasticizer is necessary in the processing of Septon Bio. This prevents oil migrating to the product surface (oil bleeding). The original rigidity and non-slip properties of products containing Septon Bio are retained in the long term. Thanks to its extensive positive characteristics, Septon Bio can be used in a large variety of areas, such as in adhesives and composites, sealants, gels, foams, films, fibers and nonwoven fabrics as well as in applications calling for high grip. MT www.kuraray.eu Fig. 3: Renewable raw materials: The biological component of the new copolymer Septon Bio – beta-farnesene from Amyris – is produced from sugar sources such as sugarcane. 400% 350% 300% 250% 200% 150% 100% 50% 0% Hardness MFR Active site PSt SEPTON Bio-series (HSFC) Elongation Permanent Set Sugarcane ϐ - Farnesene Poly (ϐ - Farnesene) Compression Set @ RT Rebound resilience Fig. 2: Sticking tight: Septon Bio, the new bio-based copolymer from Kuraray, has very good adhesive properties and is therefore ideal for adhesives and composites. Fig. 4: Versatile: Septon Bio, the new bio-based styrene farnesene block copolymer (HSFC) from Kuraray, has numerous advantages over conventional styrene block copolymers (HSBC), such as very low compression set and low rigidity. SEPTON Bio-series (HSFC) Coefficient of static friction (Dry) Coefficient of static friction (Wet) PSt 26 bioplastics MAGAZINE [06/17] Vol. 12

Processing Optimize processability of bioplastics Working closely with sustainability partner, Dynisco, (Franklin, Massachusetts, USA,) Glycon Corp. (Tecumseh, Michigan, USA,) has incorporated Dynisco’s breakthrough technology in analytical instrumentation known as the Dynisco ViscoIndicator Online Rheometer into their screw design protocol. The ViscoIndicator provides continuous measurements of melt flow rates, apparent viscosity or intrinsic viscosity directly on the Glycon lab extruder. Dynisco aims to provide a window into the process for processors of all sizes in order to simplify rheology and improve quality and profitability. Glycon is maximizing this information by utilizing it in their screw design protocol to determine the best type of screw to run any bioplastic, composite, or blend of materials, as well as to determine the specific geometry and flight configuration of the feedscrew. Glycon has been designing feedscrews for the plastics processing industry for over 40 years. Whether the process is extrusion, injection molding or blow molding, the feedscrew design has a major effect on the quality and quantity of the end product being produced. As more bioplastics that have a favorable impact on the environment are introduced, key factors in their acceptability by manufacturers will be cost and processability. With accurate rheological data on the material, whether it be virgin material in pellet form, a blend of virgin or re-grind, a composite of plant based and recycled or even recovered ocean plastics, accurate rheological data, combined with Glycon’s experience and state-of-the-art instrumentation in their Innovation Lab, will provide the critical link to maximize output rates, provide a homogeneous mix and deliver a high quality melt on the new polymers being introduced. Protocol for developing Bio-Screw ® designs 1. Obtain and review material data sheets. 2. Analyze and determine material form and bulk density. 3. Establish processing goals and objectives. - desired output rate - discharge pressure - discharge melt temperature 4. Select processing conditions based on processing goals. - screw speeds - feeding rate- barrel temperatures 5. Select screw type and geometry. - conventionally flighted metering screw - barrier screw - distributive mix/melt screw - grooved or smooth feed - mixers required 6. Run material(s) monitoring: - temperature - pressure - apparent/intrinsic viscosity - melt flow rate - shear rate - viscosity at different shear rates - shear sensitivity 7. If more than one material is tested, run a comparative analysis. 8. Optimize performance: - adjust temperature profile - adjust head pressure - adjust screw speed - change/modify feedscrew 9. Prepare a detailed report on the test including: - number of trials - temperatures and screw speeds - horsepower - lb or kg/hr/rpm - torque - energy consumption - melt quality 10. Generate a screw design recommendation. The Innovation Lab, equipped with Dynisco’s ViscoIndicator, gives Glycon state-of-the-art capability specifically targeted at sustainable materials and the circular economy. With live streaming available, material tests can be viewed around the globe in real time. MT www.glycon.com bioplastics MAGAZINE [06/17] Vol. 12 27

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