Abstract
In this paper, a novel titration method using potentiometry was proposed. The titration of hydroperoxide content in thermal-degraded PP-impact copolymers was performed by this novel potentiometry method. In the initial degradation step of the copolymer containing antioxidant, the production of hydroperoxide was not observed because of existence of antioxidant. After the antioxidant was completely consumed, the production of hydroperoxide began to be observed. This behavior completely consisted with that of the decrease in the molecular weight measured by GPC. This result implied that the beginning of degradation was accurately caught by this titration of hydroperoxide. Moreover, this titration method was more sensitive to the hydroperoxide content as compared with the conventional titration such as UV and manual titration by iodimetry, and its limit of hydroperoxide detection was found to be 2meq.kg-1 (mmol·kg-1). It was concluded that this novel titration method was a very powerful tool for the estimation of PP degradation.
