Determination of volatile compounds in poly(propylene) recyclates and methods for fogging prevention

This master’s thesis presents an investigation of the phenomenon of fogging, utilizing four selected filled poly(propylene) materials of virgin and recycled grade. Fogging is characterized by the formation of a hazy film on a surface, caused by the outgassing of substances from plastic components. The analysis of fogging residues was conducted quantitatively in the fogging test according to DIN 75201-B and qualitatively via Soxhlet extraction and solution precipitation with subsequent liquid GC-MS. Moreover, the materials were investigated with PyGC-MS which yielded results that were the most consistent with similar studies. (Methylated) alkanes and alkenes with a chainlength of at least 16 C-atoms were revealed as the primary contributors to fogging, along with certain polymer additives. In subsequent steps, selected additives were incorporated into the PP matrix with the objective of reducing the amount of outgassing of the identified substances and consequently to reduce fogging.