Renewable polymers

DuPont Engineering Polymers has announced that it is moving forward with plans to produce a new family of high-performance thermoplastic resins and elastomer products made with renewable resources.

The new products are DuPont Sorona polymer and DuPont Hytrel made with renewable resources. The key ingredient in Sorona is Bio-PDO, which is derived from corn sugar using a patented and proprietary fermentation process. Bio-PDO is a replacement for petrochemical based 1,3-propanediol (PDO) and/or 1,4-butanediol (BDO). DuPont Hytrel made with renewable resources will be produced using a new DuPont polyol made with Bio-PDO.

Production of DuPont Sorona polymer with Bio-PDO will begin next year. DuPont Hytrel made with renewable resources will be available in late 2007.

“With these new products, we will be able to offer our customers the benefits of renewably sourced materials – reduced dependence on petrochemical sourcing and a positive impact on the environmental life cycle of their products.” said Nandan Rao, vice president, global technology for DuPont Performance Materials.

In addition to replacing petrochemicals with renewable resources, the manufacturing of Bio-PDO requires approximately 40 percent less energy to produce than its petrochemical-based counterpart, saving the equivalent of about 10 million gallons of gasoline per year, based on annual production volumes of 100 million pounds of Bio-PDO.

“Both of these new products will contribute to our corporate goal of deriving 25 percent of our revenue from non-depletable resources by 2010,” said Rao.

DuPont claims the performance and processing characteristics of Sorona and Hytrel made with renewable resources are as good as or better than those of current products made wholly from petrochemicals. “Each of the new polymers based on renewable resources has special performance attributes that may drive choices in some applications,” said Rao.

Among engineering plastics, Sorona exhibits performance and moulding characteristics similar to PBT (polybutylene terephthalate).“In addition to good strength and stiffness, we see improved surface appearance and gloss, good dimensional stability and laser weldability.”

Preliminary evaluations comparing current Hytrel to Hytrel made with renewable resources show properties are mostly similar with a few improvements. Applications for Hytrel made with renewable resources are similar to the current products. Examples of major uses include extruded hose and tubing for automotive and other industrial uses, blow moulded boots for automotive constant-velocity joints, injection moulded parts such as air bag doors and energy dampers.


Loudon, Tennessee (US) will be home for the world’s largest aerobic fermentation plant for the production Bio-PDO. The plant is owned and operated by DuPont Tate & Lyle Bio Products, an equally owned joint venture of DuPont and Tate & Lyle. It is scheduled to come on stream later this year and will produce 100 million pounds of Bio-PDO (over 45,000 metric tons) per year.

Sorona polymer is made by polymerizing Bio-PDO with either terephthalic acid (TPA) or dimethyl terephthalate (DMT).Sorona polymer with Bio-PDO will be produced at the DuPont plant in Kinston, North Carolina, and ready-to-mould compounds will be produced in Parkersburg, West Virginia, USA.

Both Hytrel products have polymer chains consisting of hard and soft segments. Hytrel made with renewable resources will offer soft segments produced with a bio-based polyol, PO3G, instead of a petrochemical polyol, such as PTMEG. The bio-based polyol and Hytrel made with renewable resources can be produced in DuPont’s existing facilities.