ORGS5-0609
From Waste to Value: Catalyst-assisted Thermomechanical Strategy for Polypropylene Valorisation and Polyolefin Compatibilization
Topic
GS5. Graduate Student Oral Session V: Sustainable Polymers and Circular Materials
When and Where
Sep 28, 2026
15:24 - 15:36
Room 105
Session Chairs
Taehoo CHANG
Taejun EOM
Chae Bin KIM
Presenter(s)
Moon Paul (Deakin University)
Co-Author(s)
Abstract
Global plastic production exceeds 400 million tonnes annually, with polyolefins accounting for more than half of this volume. Among these, polypropylene (PP) is one of the most widely used plastics and a major contributor to plastic waste. Despite mechanical recycling efforts, large quantities of PP continue to be landfilled, incinerated, or downcycled, highlighting the need for innovative circular strategies to recover value from waste streams. This study presents an integrated waste-to-resource approach that combines thermomechanical catalytic processing of PP and value recovery within a single circular framework.
Metal-modified montmorillonite (MMT) catalysts were incorporated into PP during reactive extrusion, where processing conditions transformed the extruder into a continuous pseudo-pyrolysis reactor. The effects of catalyst-assisted degradation on PP were evaluated using TGA and DSC. Controlled degradation generated low-molecular-weight species containing chemically active functionalities. After processing, solvent-assisted extraction was employed to recover the degradation-derived extractable products. Chemical characterization revealed the presence of functionalized species containing oxygenated and unsaturated groups.
To demonstrate this circular pathway, the recovered extract was incorporated into mixed polyolefin blends containing PP and PE. Morphological, thermal, rheological, and mechanical analyses showed enhanced phase dispersion, interfacial interactions, and overall blend performance. This work introduces a novel circular materials strategy in which PP waste is transformed into functional molecules that facilitate the recycling of mixed polyolefin streams. By integrating catalyst-assisted degradation, solvent-based recovery, and waste-derived compatibilization, the proposed approach establishes a scalable pathway for converting PP waste into performance-enhancing additives, advancing sustainable polymer recycling and circular material design.
Metal-modified montmorillonite (MMT) catalysts were incorporated into PP during reactive extrusion, where processing conditions transformed the extruder into a continuous pseudo-pyrolysis reactor. The effects of catalyst-assisted degradation on PP were evaluated using TGA and DSC. Controlled degradation generated low-molecular-weight species containing chemically active functionalities. After processing, solvent-assisted extraction was employed to recover the degradation-derived extractable products. Chemical characterization revealed the presence of functionalized species containing oxygenated and unsaturated groups.
To demonstrate this circular pathway, the recovered extract was incorporated into mixed polyolefin blends containing PP and PE. Morphological, thermal, rheological, and mechanical analyses showed enhanced phase dispersion, interfacial interactions, and overall blend performance. This work introduces a novel circular materials strategy in which PP waste is transformed into functional molecules that facilitate the recycling of mixed polyolefin streams. By integrating catalyst-assisted degradation, solvent-based recovery, and waste-derived compatibilization, the proposed approach establishes a scalable pathway for converting PP waste into performance-enhancing additives, advancing sustainable polymer recycling and circular material design.
