This work deals with the study of the evolution (with temperature) of the in-phase (E) and the out-of-phase (E) moduli of polypropylene/mica composites with improved interfacial interactions by the presence of an industrial waste based interfacial modifier named as p-phenylen-bis-maleamic (pPBMA) acid grafted atactic polypropylene (aPP-pPBMA). This additive contains 15% w/w grafted pPBMA (5.010(-4) gmol(-1)) obtained from polymer industrial wastes in the Polymer Engineering Group (GIP) labs. The purpose of the work is twofold. One, dynamic mechanical analysis (DMA) has been used to evidence the improvement in properties due to the interfacial modifications by the addition of the novel interfacial modifier (aPP-pPBMA). And two, to obtain a mathematical model to predict the DMA moduli of the composite at and transition temperatures. So, a Box-Wilson experimental design considering the amount of mica particles and of interfacial agent as independent variables, and the modulus as the dependent ones at each transition was used. Thus, the final purpose of the work is obtaining forecasts for the DMA parameters as a function of the composite components and of the type of temperature dependent relaxation phenomena taking place. POLYM. ENG. SCI., 57:746-755, 2017. (c) 2017 Society of Plastics Engineers