Dresden 2020 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 24: Poster Session I
CPP 24.39: Poster
Monday, March 16, 2020, 17:30–19:30, P3
Measuring Diffusion Coefficients of Methylene Diphenyl Diisocyanate in Polymeric Coatings on Poly(dimethylsiloxane) — •Martin Wortmann1, Richard Petkau1, Waldemar Keil2, Natalie Frese3, Elmar Moritzer2, Armin Gölzhäuser3, Andrea Ehrmann1, Claudia Schmidt2, and Bruno Hüsgen1 — 1Bielefeld University of Applied Sciences, Bielefeld, Germany — 2Paderborn University, Paderborn, Germany — 3Bielefeld University, Bielefeld, Germany
Methylene diphenyl diisocyanate (MDI), as a common constituent of polyurethane, is the most frequently produced isocyanate and therefore of vital industrial importance. The diffusivity of MDI in polymeric materials is relevant i.a. due to its health hazardous properties but also due to its use in technical processes. In this work, the diffusion coefficients of MDI in eight different amorphous polymers were determined by means of a newly proposed test methodology. For this purpose, the polymers were dissolved in various volatile solvents and coated by solvent casting on individually pretreated poly(dimethylsiloxane) (PDMS) samples. By measuring the mass transfer rate and the MDI concentrations on both sides of the coating, the diffusivity could be calculated with the stationary Fickian diffusion equation. To determine the MDI concentrations, nuclear magnetic resonance spectroscopy (NMR) was used. DOSY NMR was used to determine the concentration of MDI in the liquid state and a combination of 1H MAS solid-sate NMR and thermogravimetric analysis was used to determine the MDI concentration in the PDMS substrate.