Automotive How
Automotive How bioplastics helped save the auto industry By: Richard Bell Global Automotive Development Manager Renewably Sourced Product Marketing DuPont Performance Polymers Troy, Michigan, USA Replacing petroleum-based plastics with renewably sourced alternatives “I’ll have to pay more for biobased plastics to get the same performance as a petroleum-based product.” Does that statement echo your perception when specifying plastics for automotive applications? Today’s reality is different. This article aims to change that perception, and demonstrates that biobased plastics made from renewable sources can match or exceed the performance of incumbent petroleum-based plastics at equivalent, or possibly lower, cost – while providing a more environmentally responsible product. Force majeure In 2012, the drive to sample and qualify renewably sourced resins was given extra impetus by an act of force majeure. On March 31 that year the industry suffered a critical shortage of cyclododecatriene (CDT) – a petroleum based feedstock used to produce PA12 resin – that threatened to disrupt global car production. The shortage exacerbated the already tight supply of PA12 polyamide and highlighted the industry’s dependence on petroleum based CDT to make PA12 and PA612. Immediately, automakers had to find substitute materials. Fig. 1: DuPont renewably sourced materials are used in many automotive applications. Hytrel RS thermoplastic elastomer for injection and extrusion Sorona for interior textiles Zytel RS polyamides for injection and extrusion BioFuels Sorona EP PTT polyester for molded parts Sorona for carpets and mats 12 bioplastics MAGAZINE [01/15] Vol. 10
Automotive Bioplastics – saving the industry Biobased nylons use a different feedstock supply chain that does not involve CDT. The auto industry transitioned quickly to sustainable PA610, PA1010, PA1012 and PA11 from DuPont and other suppliers in order to continue building cars. Biobased nylons along with other alternatives saved the global automotive industry in 2012 by ensuring that component supply was not interrupted – and what looked like a supply disaster became a launch pad for bioplastics. DuPont was well positioned to take the lead, having been the first resin supplier to commercialize renewably sourced (RS) nylon resins based on DuPont Zytel ® PA610 and PA1010 grades and DuPont Sorona ® polytrimethylene terephthalate (PTT), in automotive applications. In 2009 and 2011, the company earned two Society of Plastics Engineers (SPE) Automotive Division Awards for “Most Innovative New Use of Plastics for the Environment” – first for Zytel RS PA610 used in a radiator end tank exposed to a high temperature, chemically aggressive environment, and then again for Zytel RS PA1010 for providing superior thermal heat aging performance and chemical resistance to biodiesel in diesel fuel lines than petroleum-based PA12. Compounded formulations of PA610 and PA 1010 from DuPont are now broadly specified for applications ranging from mono and multi-layer gasoline and diesel fuel lines, corrugated vapor hoses, air and servo brake hose and tubing, oil cooler hose, clutch tubes, coolant and degassing pipes, and injection molded fuel connectors. Not just a green alternative “Sustainability is at the core of what we do at DuPont, and our move into biopolymers is not just about offering a green alternative,” said Richard Bell, Global Automotive Development Manager – Renewably Sourced Product Marketing, DuPont Performance Polymers. “The use of biobased polymers has allowed us to develop cost-effective new products that offer equal or better performance than incumbent oil-based products, with no compromise.” The polymers contain between 20 % and 100 % renewably sourced content from non-edible plant sources that do not compete with the food chain, such as castor plants, and have the added advantage of enabling a reduction in environmental footprint and CO 2 emissions. The broad range of commercially available DuPont RS polymers includes: • Hytrel ® RS thermoplastic elastomer for injection and extrusion; • Sorona ® EP PTT polyester for injection molding and fibers; and • Zytel ® RS PA 610, PA1010 and HTN highperformance polyamides (HPPA) for injection and extrusion molding. Retention elongation at break [%] 20 0 -20 -40 -60 -80 -100 0 140 120 100 80 60 40 20 0 0 Biodiesel aging at 125 °C with PA1010 vs PA11, PA12 100 200 300 400 500 600 700 800 900 1,000 Biodiesel B30 aging at 125 °C [h] Air oven aging - notched charpy Aging time [h] PA12 plasticized PA11 plasticized PA12 fuel grade Zytel RS PA1010 Fig. 2: Zytel RS PA1010 shows better retention of elongation at break than PA11 and PA12 after 1,000 hours aging at 125 °C in biodiesel B30. Notched charpy [kJ/m 2 ] 90 °C Zytel RS PA610 100 °C Zytel RS PA610 110 °C Zytel RS PA610 90 °C PA12 plasticized 100 °C PA12 plasticized 110 °C PA12 plasticized 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000 Fig. 3: Superior thermal heat aging characteristics of Zytel RS PA610 versus PA12 demonstrates its suitability for hot underhood applications. bioplastics MAGAZINE [01/15] Vol. 10 13
