PIN FR for plastic waste upcycling
Phosphorus PIN FR from THOR (pinfa member) with chain extender enabled upcycling of post-consumer PET. Secondary PET (polyethylene terephthalate) granules from post-consumer mixed plastic bottles was re-compounded (melted and extruded at 250°C) with an organic phosphorus PIN FR at 0 – 10% loading and a chain extender (a styrene-acrylic multifunctional epoxide oligomeric agent from BASF, pinfa member) at 0 – 1% loading. At 10% PIN FR, peak heat release rate of injection-moulded 5 mm thickness extruded samples was reduced by c.45% but smoke production increased by c.15%. Tests of foaming were also carried out, using carbon dioxide blowing agent, showing that the recycled PET with chain extender and PIN FR achieving up to 660 kg/m3 with 7 µm cell size. The authors conclude that the combination of this phosphorus PIN FR and chain extender allow upcycling of post-consumer PET to performance rigid foam, with synergies between the chain extender and the PIN FR for both fire performance and performance and processing characteristics.
“Enhanced Flame-retardant Performance of Undervalued Polyethylene Terephthalate Waste as a Potential use in Foamed Materials”, M. Santiago-Calvo et al., J. Polymers and the Environment, 2024 https://doi.org/10.1007/s10924-024-03424-0
