Preparation and characterization of waterborne polyurethane/silica hybrid dispersions from castor oil polyols obtained by glycolysis poly (ethylene terephthalate) waste

摘要

Castor oil polyols (COLs) have been synthesized from glycolyzed oligoester polyol in order to produce waterborne polyurethane (WPU)/silica hybrid dispersions. Soft drinks poly(ethylene terephthalate) (PET) bottles were depolymerized by glycolysis with different molar ratio of poly(ethylene glycol) ( PEG 400), in the presence of zinc acetate as catalyst. The obtained glycolyzed products were reacted with castor oil (CO) to attain castor oil polyols by the process of transesterification. Five castor oil polyols were used with hydroxyl values of 255, 275, 326, 366 and 426 mg KOH g(-1). Several castor oil-based, polyurethane/ silica hybrid dispersions having soft segment content of 39.6% to 28.2% and two concentrations of SiO2 nanoparticles (0.5 and 1.0) have been prepared.