Abstract Nowadays, the possibility to easy open a food package is of great interest both from the consumer and food producers’ perspective. In this study, the peel/seal properties (in particular the aging effect) of polybutene-1 (PB-1) blends and their nanocomposite films were investigated. Different blends of ethylene vinyl acetate (EVA)/PB-1, ethylene methyl acrylate (EMA)/PB-1 and linear low density polyethylene (LLDPE)/PB-1 as well as their nanoclay composites were prepared using the cast extrusion process. Differential Scanning Calorimetry (DSC) was used to investigate the thermal behavior as well as the crystalinity of the blends and nanocomposites. The effect of polymer matrix and incorporation of nanoparticles on the crystalline structure and aging of PB-1 was studied using Wide Angle X-ray Diffraction (WAXD) and T-peel testing right after sealing (green bond) as well as one week and two weeks after the heat seal process. The rate of PB-1 crystal transformation from the meta-stable to the stable crystalline form was correlated to the T-peel strength of the aged samples. Morphology of the blends and their nanocomposites is observed using Scanning Electron Microscopy (SEM) to investigate the effect of the blend morphology on the rate of the crystallization of PB-1 and peel strength of the blend films.