The new compound fits between Pebax thermoplastic elastomer (TPE), a brand from supplier Arkema, and nylon 11. Foster Corp. develops compounds for use in minimally invasive devices; the compounder is part of PolyMedex Discovery Group, which also includes plastic tubing processor Putnam Plastics. The Group also is the exclusive North American sales and distribution partner for Arkema in the medical device market for the supplier's Pebax material and also its Rilsan MED 11 and 12 polyamide grades.
Foster says the new compound has 45% greater stiffness, without a reduction in elongation, compared to Pebax 7233 MED, an Arkema TPE grade compounded from flexible polyether and rigid polyamide.
To make its NanoMed EX compounds, Foster compounds nanoparticles into a Pebax polymer-based matrix using its proprietary processing technology. The result is a polymer formulation with appearance and processability similar to that of unmodified Pebax. The company says the nanoparticles provide the material with its 45% greater flexural modulus but at the same tensile elongation as Pebax 7233 MED, and not as stiff as nylon 11. Flexural modulus is 75,000 psi (5171 bar) for Pebax 7233 MED and nearly twice this for nylon 11.