Edward Kosior

THERMAL AND MELT RHEOLOGICAL BEHAVIOUR OF COMPOSITES PRODUCED FROM WASTE PAPER AND PLASTIC

The thermal and melt rheological properties of highly filled polymer composites produced from waste papers, Recycled Paper Waste (RPW) and Liquid Paperboard (LPB), in a post-consumer Stretch-Wrap (SR) matrix have been evaluated. Thermal testing has indicated that large amounts of absorbed water are bound to the filler and, along with small levels of volatile emissions, would be released in compounding and moulding of the composite. The thermal limits of the waste paper fillers and matrix have been evaluated, indicating upper processing limits in the order of 240°C. Melt rheological testing has shown large increases in viscosity with filler volume fractions that have shown a good fit to an exponential equation. The frequency dependence of the viscosity of the composites has shown good agreement with the power-law relation and the composites have shown a decrease in relative change in viscosity with temperature compared to the unfilled matrix.

Flexible polyurethane foams from recycled PET

Plastic packaging forms a significant portion of household waste, and PET soft drink bottles represent a major percentage of the waste. Consequently, PET bottle grade material makes up a significant portion of the feedstock in the recycling plant at Visy plastics. The end uses are theoretically many, however, there are few applications for less purified grades of recycled PET. This paper presents the preliminary results of an industry based collaborative research project which aims to investigate the breaking down of recycled PET into its chemical building blocks using glycolysis. The main objective is to produce a polyester polyol for the polyurethane industry from recycled PET and to compare the properties with that of a virgin resin.

In-situ Reactions between Recycled Polyethylene Terephthalate and Nylon 6 Blends

In this research the interaction between Nylon 6 (N6) and Recycled Polyethylene Terephthalate (RPET) have been examined. In particular the condensation reaction between ester and amine groups during the solid stating process. This has the effect of creating an in-situ compatibaliser between the two incompatible phases in the blend. Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) are the techniques used to identify the presence of the RPET/N6 copolymer. It was found that there was a copolymer formed during solid stating and that this was a time dependent reaction.

Contaminants and their levels of retention in extruded, recycled poly(ethylene terephthalate) from curbside collection. Part 1 : extraction kinetics and particle size effects

In the first phase of our studies of the contaminants and their levels in curbside-collected poly(ethylene terephthalate) (PET) subjected to a recycling process, we analysed the washed and dried, shredded PET (flake). Of the semi-volatile contaminants found, 26 were below the US FDA threshold of 215 ppb and six were above. Additionally, it was found that surface levels of contaminants far exceeded average concentrations in the bulk of the flake, raising questions about the appropriateness of sampling procedures. In this second phase (again using dichloromethane Soxhlet extractions for the most part), we examined contaminant levels after the flake was subjected to vacuum extrusion, to complete the recycling process. Initially amorphous, extruded pellets were annealed to introduce crystallinity and allow grinding, in order to examine the effect of particle size. Much reduced concentrations of contaminants were found (all <215ppb). There were no significant differences in contaminant levels as a function of particle size, thus indicating a uniform distribution throughout the extruded material and no need for particle size reduction before sampling and analysis. However, whilst 3 h was sufficient to obtain quantitative extractions from the ground, annealed particles in each size range (0-300 μm, >300-425 μm and >425-700 μm), approximately 8 h were required for the unground annealed pellets.