Pragmatically upcycle industrial mixed plastic waste from shredder residue
File(s)
Author(s)
Singkronart, Kanjanawadee
Type
Thesis
Abstract
Reprocessing industrial mixed plastic from shredder residue through conventional extrusion and injection moulding results in inferior mechanical properties compared to its virgin counterparts due to immiscibility of the polymer blends. This thesis describes methods to practically upcycle industrial mixed plastic from shredder residue through a composite and non-homogenous melt consolidation approach. Wood flour, glass fibres and carbon fibres reinforcement were shown to improve the stiffness and strength of mixed plastic. The increase in tensile, flexural and fracture properties of the reinforced mixed plastics was governed by the fibre or filler, instead of the inferior mixed plastic. Lifecycle assessments revealed that reinforcing mixed plastic with 40 wt.-% of wood flour produced the lowest global warming potential and abiotic depletion potential of fossil fuel. This thesis further investigated the solutions to tackle the brittleness of mixed plastic. Without the intimate polymer mixing, the contact between immiscible phase boundaries is minimised, resulting in a progressive failure and a ductile fracture toughness response. Digital image correlation and fractographic analysis also revealed a ductile response of large polymer domains with the failure at the phase boundaries. In addition, the brittleness of mixed plastic was tackled by reinforcing with rayon fibres through wet powder impregnation process. Adding 10 mM of sodium dodecyl sulfate allowed the formation of a homogeneous distribution of the mixed plastic in the rayon fibres during the manufacturing of the composites. These composites possess a progressive tensile failure with increased in impact strength. This thesis demonstrated the pragmatic solutions for upcycling industrial mixed plastic opening up opportunities for the use in various higher value applications, ultimately diverting it away from landfill and incineration.
Version
Open Access
Date Issued
2024-01-27
Date Awarded
2024-04-01
License URL
Advisor
Lee, Koon-Yang
Shamsuddin, Siti Rosminah
Sponsor
Thailand
Publisher Department
Aeronautics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)