Quantitative trap analysis of grafting-modified polypropylene based on thermally stimulated depolarization current

•MMA-grafted PP is prepared with enhanced DC resistivity and more deep traps.•Trap characteristics of MMA-grafted PP based on TSDC is quantitatively analyzed.•MMA deepens the inherent PP trap depth and introduces a new deep trap of 1.8 eV. In this paper, the thermally stimulated depolarization current (TSDC) spectrum of methyl methacrylate (MMA)-grafted polypropylene is quantitatively analyzed by our TSDC peak separating algorithm. The separated trap peaks and extracted trap parameters are verified to be effective and credible by the experimental peak-separating method based on thermo-cleaning. The trap analysis on pristine and MMA-grafted polypropylene is carried out and indicates that grafting MMA can introduce a new high-depth trap peak at about 1.8 eV, meanwhile the intrinsic trap of polypropylene is deepened. This work would provide an opportunity to advance the understanding of trap characteristics in grafting-modified polypropylene.