Test Method of Grafting Ratio of Maleic Anhydride Grafted Rare Earth Isoprene Rubber

Maleic anhydride grafted rare earth isoprene rubber (IR-g-MAH) is synthesized from maleic anhydride(MAH) and polymerization solution of rare earth isoprene rubber (IR) by solution grafting reaction. Taking test method of grafting ratio of IR-g-MAH as the research object, the direct titration method and the back titration method are studied, moreover, the determination conditions of the direct titration method are optimized. Results showed that the direct titration method has higher accuracy, better repeatability and simpler operating process. The optimal determination conditions are as follows: hydrolysis reagent is ethanol, sample dosage is 0.2~0.5 g, the concentration of standard KOH-ethanol solution is 0.02~0.06 mol/L.