Materials Performance
Materials Performance products with high biocontent polyurethanes Found in mattress foam and floor coatings, in textile adhesives and electronics, in membranes and construction materials, and in hundreds of thousands of other products, polyurethanes make a vital contribution to our functioning world. Polyurethanes are typically formed by the reaction between polyols – molecules with two or more reactive hydroxyl groups – and isocyanates. The vast range of properties polyurethanes can attain are driven in large part by the molecular structure of their component polyols and isocyanates and by the ratio of those components. Polyurethane manufacturers can adjust for hardness, flexibility, impact strength, resiliency, and tear and abrasion resistance, among other characteristics, by selecting the type and proportions of these building block molecules. Building with the WING Platform Checkerspot, an advanced materials company, is focused on expanding the palette for renewable building blocks. The team at Checkerspot is making high biocontent polyurethanes using polyols it generates from unique microalgal oils. The company has focused on developing cast polyurethane and rigid polyurethane foam formulations with the objectives of achieving end product performance with high biocontent. As a first product, Checkerspot selected a demanding and highly visible application set, backcountry skis, to demonstrate its materials. The taxing elements of the backcountry and the conditions of ski pressing provided a rich selective environment to solve materials and process challenges. Today, Checkerspot’s microalgaederived cast polyurethane (Algal Wall sidewalls) and polyurethane-based foam composite (Algal Core ski cores) have demonstrated performance benefits in the award-winning backcountry skis sold through Checkerspot’s outdoor brand, WNDR ® Alpine (Figures 1 & 2). The brand just announced an expansion into snowboards and split boards and is leveraging Checkerspot’s formulations in these new applications. Checkerspot recognized that in order to accelerate development and adoption of new molecules and materials, it needed to bring together elements and capabilities that reduce the friction and drop-off points that can hamper innovation. The company’s Wing Platform provides for a continuous handoff, an integrated through line, that connects molecular biology, materials science, and fabrication with end consumer engagement. Emergent properties of the raw and intermediate materials can be evaluated against process and product requirements, and learnings made at different points of the platform can be leveraged more readily. Charles J. Rand, Checkerspot’s Vice President of Materials Science and Applications Development, who additionally oversees formulation optimization and fulfilment, points to an advantage of the Wing Platform, “By connecting raw materials development, formulation design, manufacturing, and product feedback all in one organization, we can quickly iterate to dial in optimized material properties while being mindful of production and end-use performance”. Seeking change – and change agents The growing number of companies moving to reduce Scope 3 emissions, the rise of consumer awareness and concern for sustainability, and brands’ drive to differentiate their products is leading to greater demand for fossil-based carbon alternatives. Checkerspot’s aim is to extend the Wing Platform’s capacity for iteration, renewable molecule and material development, process efficiencies, and customer engagement to others seeking to build with more renewable starting points. Among the loudest voices seeking renewable and performant materials are industrial designers, product developers, and creatives. Checkerspot will be offering casting kits to engage and encourage the tastemakers who influence material selection. Expected to debut this fall, the Figure 1: The 2023 WNDR Alpine Intention 108 backcountry ski features a composite of domestically sourced aspen and algal hard foam (Algal Core) and an algal cast polyurethane sidewall (Algal Wall) to boost ride quality without increasing weight. Figure 2: Materials scientist Neal Anderson pours Checkerspot’s Algal Wall cast polyurethane to create WNDR Alpine ski’s sidewall. Checkerspot Design Lab, Salt Lake City, UT, USA. 44 bioplastics MAGAZINE [05/22] Vol. 17
By: Adrienne McKee Director of Platform Partnerships Checkerspot, Inc. Berkeley, CA, USA Materials Checkerspot ® Pollinator Kit will ship with the Pollinator Series Cast Polyurethane Resin, a hand-mixable A and B side system that can produce durable and long-lasting parts. The formulation is compatible with standard tooling, moulding materials, and processes and is amenable to a wide range of colouration. Different kit options target casting novices as well as experienced users. The Pollinator Series casting resin represents a shift away from fossil fuel-based incumbents; each casted item made solely from the resin will be ≥55 % biobased (ASTM D6866) (e.g. Figures 3 & 4). The company envisions this kit and formulation to support rapid prototyping as well as be useful in product applications requiring fine detail moulding and a high-quality surface finish. Beyond materials sales, Checkerspot is partnering with brands, chemical multinationals, and manufacturers across different pillars of the Wing Platform. In a partnership with DIC (Tokyo, Japan), the company created a new class of novel, high-performance polyol that is being developed into commercial applications. Checkerspot recently announced a collaboration with Will & Co. to provide European partners with high performance, high biocontent polyurethane systems with attractive sustainability profiles. Checkerspot’s combined ability to customize high biocontent polyurethane formulations and work closely with customers’ manufacturing is a valuable proposition to accelerate materials adoption, as is evident by Checkerspot’s joint development work with DPS, the largest ski manufacturer in the USA. Says Rand of Checkerspot’s team, “We are eager to share the Wing Platform’s efficiencies, honed through close iteration between formulation design and WNDR Alpine product manufacturing, to create additional biobased products that meet the manufacturing complexities of our partners. Our goal is to expedite the use of renewable products in daily life”. Natural oil polyols (NOPs), polyols derived from plant oils, have long been deployed in PUs. As polyols comprise a large portion of polyurethane formulations, NOPs can displace fossil-based polyols on a substantial scale. However, the structures of NOPs are dictated by the biology of the castor bean plant, the soybean plant, or the palm plant. Checkerspot’s molecular foundry leverages microalgae in order to adjust the structure of the polyols it uses. By recapitulating the biology of a plant inside of a fast-growing, sugar-eating microbe, Checkerspot can more rapidly biomanufacture an array of polyurethane raw materials. Added benefits come in play into the forms of reducing land, water, and GHG relative to more traditional ways of making oils. Checkerspot’s cast polyurethanes, some reaching over 70 % biocontent (ASTM D6866), are currently formulated to achieve hardness ranging from 60 Shore A to 75 Shore D. The company’s rigid foams are suitable for milling and carving, and can realize a range of densities and compression sets. Current rigid foam formulations are produced with >41 % (ASTM D6866) biocontent. Several of the company’s polyurethane systems and their underlying renewable building blocks have earned the US Department of Agriculture (USDA) Certified Biobased Product label. This means that manufacturers using Checkerspot’s formulations are able to display a unique USDA label that highlights their percentage of biobased content. https://checkerspot.com/ https://www.dic-global.com/en/ Figure 3. ≥55 % biobased content climbing holds made with the Checkerspot Pollinator Series Cast Polyurethane. Figure 4. ≥55 % biobased content phone cases made with the Checkerspot Pollinator Series Cast Polyurethane. bioplastics MAGAZINE [05/22] Vol. 17 45
