Thermal, structural, and rheological modifications in recycled polyethylene terephthalate for a sustainable alternative source for additive manufacturing

Abstract

AbstractThis work reports the thermal, rheological, and crystallographic structural behavior of recycled polyethylene terephthalate (rPET) derived from bottle waste. The intent is to optimize it to an upcoming source for additive manufacturing by modulating its behavior using a chain extender triphenyl phosphite (TPP), nanofiller montmorillonite (MMT K‐10), and catalyst antimony trioxide (Sb2O3). FT‐IR (Fourier Transform Infrared) analysis showed an increase in absorbance due to the Sb2O3. The thermal analysis of the rPET using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) ascertains a 10°C decrease in Tg with a substantial increase in the degradation onset of 7°C due to MMT content. The melt flow index (MFI) study showed an increase with a similar range in intrinsic viscosity and weight average molecular weight (Mw) due to the additives. The percentage crystallinity, interlayer distance, and average crystallite size are determined and analyzed by X‐ray diffraction (XRD) and DSC curves. The results are within the comparative range of both tests. The presence of Sb2O3 with higher MMT content showed agglomeration, and increased TPP showed low crystalline properties. These results provide that rPET can be altered to manufacture feedstock to suit different 3D printing techniques for prototyping.