Although polypropylene (PP) foams are interesting in various industrial applications due to its properties, PP is of limited use in the fabrication of microcellular foams with even microcellular bubble cells due to its rheological properties, namely its typically low strain-hardening. Herein, the influence of rheological properties on even microcellular morphology of foam/film structure, resulting in good mechanical and dielectrical properties was investigated. Two types of long chain branching polypropylenes (LCBPP) were used and named as LCBPP1 and LCBPP2. The talc micro-particles were used as a nucleating agent and its rheological effect was investigated. Talc crystallization effect was investigated with DSC. In shear flows, LCBPP2 exhibited noticeable changes with the talc content between 1.0 and 1.5 wt% while LCBPP1 exhibited no significant changes with particle content. Both LCBPPs exhibited strong strain-hardening behavior with Trouton ratios which is higher than 3 at all extensional rates, regardless of talc content. Furthermore, LCBPP2 showed stronger strain-hardening than LCBPP1. 16 and 32 layered foam/film structures were fabricated with both LCBPPs, and while the strain-hardening of LCBPP2 resulted in the stable layers and non-coalesced cell structure, the relatively weak strain-hardening of LCBPP1 caused cell collapse and layer rupture. Therefore their morphology of samples were different in terms of the cell density and mechanical properties. In addition, dielectric properties of PP foam/PP film were investigated in terms of morphology for energy harvesting material applications with electric displacement-electric field loop and broadband dielectric spectroscopy. The more layered PP foam/PP film showed high dielectric constant at all electric fields because of the surface area inside. Moreover, the dielectric constant of the samples increased with increasing temperature because of electron conduction and also increased at below 0 oC due to interfacial