Seeded-emulsion polymerization of styrene with waterborne polyurethane stabilizer via 60Co gamma ray

In this work, waterborne polyurethane (WPU) was synthesized and its molecular weight and critical micelle concentration (CMC) were measured. Latex of polystyrene (PS) was successfully prepared via 60Co-γ ray radiation-induced seeded emulsion polymerization using WPU as seeds and stabilizer. The polymerization process was investigated by conversion-time curves at different stabilizer contents and different absorbed dose rate. Polystyrene and polyurethane hybrid latices were dried and extracted with methanol. The characterization of polymer was carried out by FT-IR, X-ray photoelectron spectroscope (XPS), the results testified the grafting reaction between polystyrene and polyurethane. Ratio percentage of grafted WPU versus the total content of WPU (GPU) in this system was investigated via 1H-NMR spectroscopy. Compared with chemical initiation method, γ-ray radiation is an effective method to improve the grafting reaction between WPU and styrene.