Pilot interlab comparisons of methods to simulate weathering or machining of nanocomposites and to detect fragments released

W. Wohlleben, J. Mueller, T. Nguyen, L. Sung, S. Vazquez-Campos, M. Voetz, T.A.J. Kuhlbusch, M. Wiemann
BASF SE, DE

Keywords: lifecycle, nanocomposites, protocols, structure-property relationship

Summary:

Here we report how the nanoGEM and MARINA projects have contributed to protocol optimization by small-scale pilot interlab comparisons, terminated in 2013, thus preparing the ground for broad interlab validation: 1. nanoGEM weathering: ISO weathering simulation can be extended by sampling and quantification to assess what is released from aging nanocomposites, and at which rate. A pilot interlab comparison (NIST, Leitat, BASF) on SiO2 release from polyamide plastics was performed both with spontaneous release during weathering and with induced release by immersion. 2. nanoGEM sanding: On the same material, three mutually similar sanding setups (Bayer, IUTA, BASF) provided identical quality of release, namely PA fragments with embedded SiO2, but they differ in the quantity of aerosol emission and the size of the PA fragments. 3. MARINA weathering: Comparative weatherization release on different nanofillers (SiO2, CB, CNT) in the same polyurethane confirmed the hypothesized structure-property-relationship of black vs. transparent nanofillers and particle vs. fibre shapes. In summary, the convergence between labs and the plausible scaling of release between different materials supports that testing of release during the manufacturing and use phase of nanocomposite materials is possible. The sanding and weathering methods seem ripe for pre-normative activities.