Preparation and characterization of waterborne polyurethane containing PET waste/PPG as soft segment.

ABSTRACT Soft drinks poly(ethylene terephthalate) (PET) bottles were depolymerized by glycolysis using a 1 : 3 molar ratio of PET repeating unit to glycols like neopentyl glycol (NPG) and dipropylene glycol (DPG). Further, a series of waterborne polyurethanes (WPUs) was synthesized using pure polypropylene glycol (PPG), and glycolyzed oligoesters/PPG blends in different molar ratios as soft segment. Thermal property of WPU was tested by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Moreover, viscosity and particle size of WPU were also investigated. The results show that introduction of a certain amount of glycolyzed oligoester to soft segment makes the degree of hard-soft domain microphase separation smaller, and can also improve thermal stability of WPU. Furthermore, WPUs synthesised from glycolyzed oligoesters and PPG blends possess larger particle size, better particle size distribution, relative lower and more stable viscosity. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42757. [ABSTRACT FROM AUTHOR]