Diffusion Transport in Reconstructed Semi-Crystalline Structure of Polyolefins

Summary: Diffusion of penetrants (e.g., monomers) in polyolefins is important not only in their manufacturing and down-stream processing, but also in packaging and separation applications. We propose a general methodology linking the semi-crystalline structure of polyolefins to their application properties. This methodology comprises of AFM imaging of semi-crystalline structure, reconstruction of 3D replica of semi-crystalline polymer and calculation of application properties (e.g., diffusivity) depending on 3D morphology. Our algorithm is capable to achieve realistic crystallinities of reconstructed samples up to 70% and to reconstruct spherulites with preferential orientation of lamellae. We demonstrate and discuss difficulties experienced during AFM imaging of HDPE morphology, particularly the dependence of resulting AFM image representing the distribution of crystalline domains on the sample preparation including etching.