Effect of h-NS Content on the Viscosity, Morphology, Gelation, and Mechanical Properties of the Modified-rPET from Bottle Waste

Abstract

This research developed the modified-recycled poly (ethylene terephthalate) (modified-rPET) filament by decreasing the crosslinked-gel content inside the filament, by adding various contents of hydrophobic nanosilica (h-NS). This research also studies the viscosity, morphology, h-NS dispersion, and mechanical properties of the modified-rPET/h-NS, by using a rotational rheometer, a scanning electron microscope, a micro-XRF spectrometer, and a universal testing machine, respectively. rPET flakes were dried to deplete the moisture. Then, they were mixed with additives and h-NS at 0, 1, 2, 3, 4, and 5 pph, and were extruded to be compound using twin screw extruder. The modified-rPET/h-NS extrudates were investigated into two parts. Firstly, was observed on the process-ability, morphology, and gel content along the filament. Consequently, the viscosity, mechanical properties, and h-NS dispersion were investigated. The results showed that the best formulation that is easy to process and has the lowest gel content along the filament, was NS1. Other results, shear-thinning rheology behaviors were observed for all formulations. The mechanical properties, including ultimate tensile strength and elongation at break decreased, as the h-NS content increased. At higher content of h-NS (NS4 and NS5), the gel content increased significantly, therefore the h-NS agglomeration occurred, which was different from crosslinked gels.