Effect of compatibilizers on blends of immiscible polymers containing polyolefins

Fabian Schuster

Research output: ThesisMaster's Thesis


The optimization of the recycling of multi-material polymer waste streams using maleic-anhydride (MAH) grafted compatibilizers presents several challenges. Focused post-industrial waste streams in this study are multi-layer packaging films based on polyolefins like polyethylene (PE) and polypropylene (PP) with polyamide (PA) as a barrier layer. Understanding the effect of the processing as well as the differences in morphology of compatibilizer types on recycling film product properties has been investigated. With the access to the DowDuPont portfolio of compatibilizers a range of potential chemicals were selected to be qualified for recycling of the mixed polymer waste streams. The study is split in two cases: PE with PA and PP with PA. Following a screening process based on films produced with virgin polymers the best compatibilizer and required amount for chosen waste streams was determined and the results were validated using real industrial waste. The produced recycling films have been evaluated and compared using standard laboratory tests like tensile, tear and impacts testing, optical properties, DSC, FTIR, MFR and microscopy. Processing with a twin-screw extruder showed a strong improvement especially in mechanical properties over the single-screw extruder. The backbone of the compatibilizer, that is responsible for the blending with the non-polar matrix and creating the interface between the polar polymer phases, was found to be a very influential factor on the final film properties. With appropriate processing and 5 wt.-% of compatibilizer it was possible to produce recycling films with mechanical properties in the range of the virgin polyolefin matrix and the added potential with the PA to use the increased strength of the films. The application of the recycling material presenting a relatively high viscosity could be in new film applications with higher mechanical requirements. Optical haze leading to a milky-white appearance indicated the recycling nature of the film. Overall it was established, that the compatibilizer backbone is the major influence for performance of in the blend. In cooperation with industry partners the in-house recycling could be improved with the gained know-how for optimization of polymer waste management. This added commitment to sustainability may set a basis for future post-consumer recycling.
Translated title of the contributionDer Effekt von Kompatibilisatoren auf unmischbare Kunststoffe mit Polyolefinen
Original languageEnglish
Awarding Institution
  • Montanuniversität
  • Holzer, Clemens, Supervisor (internal)
Award date28 Jun 2019
Publication statusPublished - 2019

Bibliographical note

embargoed until 25-04-2024


  • Compatibilizers
  • Recycling
  • Sustainability
  • Polymer processing
  • immiscible polymers
  • compatibility

Cite this