Structural Study of Modified-Recycled PET from Drinking Bottle Waste by Using Multifunctional Chain Extenders

This research aimed to recycle polyethylene terephthalate (rPET) from drinking water bottles using a commercial multi-functional chain extender (Joncryl®ADR4468) with low content, to improve the properties of low molecular weight recycled PET, giving it a long chain with branching structure. The effects of the chain extender on the structural change, viscosity, thermal properties and thermal stability of modified recycled PET (modified-rPET) were studied by using Fourier transform infrared (FTIR) spectrometer, a rotational rheometer, a differential scanning calorimeter (DSC) and thermogravimetric analysis technique (TGA). The results indicate that the chain extender can increase the molecular weight and modify the structure of rPET to a long chain with branching structure and improve the viscosity. Furthermore, the thermal properties and thermal stability analysis from this research could be great evidence to support the assumption that the use of low dose of Joncryl®ARD4468 could turn the molecular structure of rPET into long chain with branching structure, without gel, perfectly.