High-throughput dynamic impact characterization of polymer films

An instrumented falling weight impact apparatus has been designed and constructed for high-throughput characterization of polymer films in the 5–100 m thickness range. The primary intended use of the instrument is rapid and accurate characterization of the dynamic impact response of multiple (100) positions on a combinatorial library film. This will allow future exploration of the dependence of mechanical response on polymer composition, thickness, and annealing temperature using combinatorial synthesis and characterization methods. This paper describes the instrument and presents validation measurements using polyethylene films of uniform thickness (25 m) and poly(urethaneurea) elastomers of thicknesses from 10–30 m. Measurements on the polyethylene film demonstrate the reproducibility and lack of interaction effects for multiple measurements on the same film. Poly(urethaneurea) elastomer impact measurements are used to indicate the instrument sensitivity to controlled variations in polymer chemistry and structure. In particular, the results from force-deformation profiles indicate an optimum curing temperature and the expected trend in mechanical response with respect to polyurethaneurea diamine chain extender composition.