DuPont officially launched a fully commercialized portfolio of biobased plastics at the National Plastics Exposition in Chicago that is clearly the broadest and most ambitious in the industry. Biobased resins that have been on the market for the past four or five years had limited scope. They were aimed at biodegradable packaging applications, and putting biobased polymers into the engineering arena was a far tougher challenge. “Our goal from the very beginning was to develop materials that offered equal or superior performance to the competitive materials,” Marsha A. Craig, DuPont’s global business manager for renewably sourced materials, told Design News in an interview.The three families shown by DuPont at the NPE are Sorona EP PTT-type polyesters, Hytrel RS thermoplastic elastomer, and Zytel RS thermoplastics long chain nylons (6,10 and 10,10).
The Sorona family contains 37 percent corn-based feedstock and is offered in 15 and 30 percent glass filled grades. ”We will also be selling unreinforced , toughened and other grades,” says Craig. DuPont has not yet announced any commercial applications for Sorona EP, but Craig says several customers are conducting tests with the material. A sample glass-filled Sorona EP part on display at the DuPont booth (which had a distinctly earth-friendly theme) had an excellent surface finish, one of the attributes of the renewably sourced blend. Prices for the compounds will be in the $2-$3 per pound range, and will reflect a premium for their superior attributes. Renewable content varies from 20 to 65 percent depending on the hardness grade.
The Hytrel RS is a drop-in replacement for existing Hytrels, and will be priced at a 10 percent premium, reflecting higher costs for the sustainable component, which is produced from nonfood biomass. The exact biomass is currently being kept confidential by DuPont. Target customers are seeking materials with a renewably sourced component. The first announced application is a collar for a Salomon ski boot. The third family, Zytel RS, is based on sebacic acid made from castor oil. Renewable content varies from 60 to 100 percent, depending on the grade.