Bio-based plasticizers for E/E, B&C, automotive and (soon) more

Dow Wire & Cable chose the Wire 2010 tradeshow in Düsseldorf, Germany this week to launch a new family of phthalate-free plasticizers for use in wire insulation and jacketing. The plasticizers, made from just a hair shy of 100% renewable feedstocks, have a molecular weight comparable to standard plasticizers used in these applications, but are about 20% more efficient in terms of heat stability.

Plasticizers are used in polyvinyl chloride (PVC) applications to make the usually rigid material softer and more flexible. Dow estimates global PVC use in wire-and-cable applications at about 10 billion lbs/yr, with plasticizers for these applications a 3 billion-lb/yr market. Thorne Bartlett, new business development manager at Dow Wire & Cable, told MPW that the two new plasticizers launched by Dow, marketed under the name Ecolibrium, include several crop-based components.

Heat stability with these Dow materials is better than those established plasticizers, Bartlett said, with the degree of improvement varying by application. According to Bartlett, PVC compounds containing the two Dow bio-based plasticizers can meet all regulatory requirements for flame resistance, including the UL standard for long-term heat stability, generally considered the most difficult of the lot. He said processors using the Dow materials can replace established phthalate plasticizers such as DINP or DEBP in their PVC compounds—at 20% less loading ratios—and still achieve the same Shore hardness. One of the two Ecolibrium plasticizers is for applications requiring heat stability to 75°C, the second for those requiring stability between 75°-105°C. According to a Life Cycle Analysis (LCA) conducted by Dow and reviewed by a third party, Ecolibrium-plasticized PVC compounds can help cable-makers and original equipment manufacturers (OEMs) reduce greenhouse gas emissions by up to 40%, compared to traditional PVC compounds using established plasticizers.

On the processing side, the two new plasticizers have a molecular weight similar to plasticizers currently used in these applications. Both are very soluble in PVC, though, so processors will need to have good control of addition rates. To help limit direct competition among its licensees, Dow will license these plasticizers by end-use market and by region. Jonathan Penrice, global marketing director for Dow Wire & Cable, said some licensing partners already have been chosen in Europe and North America for building and construction (B&C) applications, though these will not yet be publically named.

The supplier has worked for three years on development of the materials to ensure they meet all relevant standards and meet users' demands for processability, and anticipates use in wiring applications such as personal electronics and appliance wiring, residential and commercial building wiring, communications and data cabling, and automotive wiring. Penrice added that later this year the company likely will announced market availability of other bio-based plasticizers for other PVC applications in markets such as medical, toys, flooring and non-cable automotive parts.     

And the cost? Penrice and Bartlett said the impact on a cable's total cost would be small, with a worst case of a roughly 15% premium for B&C cable and wiring. For a residential home, such a premium translates to about $50/home, said Penrice. 

In related news earlier this week, PolyOne Corp. (Cleveland, OH) signed a joint-development agreement with biobased-chemical startup Segetis (Golden Valley, MN) to advance that company's renewably resourced plasticizer. Segetis' proprietary levulinic ketal technology can be used to create plasticizers, solvents, and modifiers for targeted polymers. PolyOne and Segetis say initial developments will be tested in the U.S., but resulting technology platforms will become globally available. —Matt Defosse