Insights into the use of zinc-mannitol alkoxide as a novel thermal stabilizer for rigid poly(vinyl chloride)

Zinc-mannitol alkoxide (Zn-Man) was synthesized through alcohol exchange reaction, and investigated by means of Fourier transform infrared spectroscopy and elemental analysis. The thermal stability of Zn-Man for rigid poly(vinyl chloride) (PVC) was evaluated by Congo red testing, conductivity measurements, thermal aging testing, thermogravimetric analysis (TGA), and ultraviolet-visible (UV-vis) spectroscopy test. The experimental results demonstrate that the addition of Zn-Man not only apparently prolonged the static thermal stability time to approximately 96.5 min but also evidently improved the initial color of PVC. More importantly, the color of the PVC sheets stabilized with Zn-Man did not change to black within 180 min; this showed that no zinc-burning phenomenon occurred. In addition, the results of TGA reveal that Zn-Man raised the initial degradation temperature of PVC to about 273.4 degrees C. UV-vis testing indicated that the presence of Zn-Man decreased the content and shortened the length of the conjugated double bonds of PVC. The possible thermal stability mechanism is discussed. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42038.