Polyolefins like polypropylene degrade during processing and lifetime through oxidation and photooxidation. The consequence of this process called autooxidation is the loss of visual and physical properties. [1] To prevent thermal degradation and ensure the maintenance of properties stabilization with suitable antioxidants is mandatory. Most standard antioxidants used today are based on petrochemistry. Due to the low molecular weight these substances show high migration tendency which may cause a contamination of the environment. [2]

In the course of sustainability and circular economy Fraunhofer LBF develops novel antioxidants with biogenic building blocks as useful alternative sources for plastic stabilizers.

Novel antioxidants have been synthesized from eugenol and combined with sulfur containing groups to provide multifunctional structures including polymers.

The antioxidant activity and stabilizing effect in polypropylene was proven by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) method, extended extrusion time, oxidation induction time measurements and long-term heat stabilization test via accelerated oven ageing. Moreover, the synthesized compounds were also investigated with regard to their process-stabilizing effect in the biopolymer polylactic acid.

[1] Schiller M, Maier R-D, Plastics additives handbook. 6th ed. München: Hanser; 2009.

[2] Hahladakis JN, Velis CA, Weber R, Iacovidou E, Purnell P. An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling. Journal of hazardous materials 2018;344:179–99.