Development of a Stable Open-Porous Structure in the Solvent-Crazed High-Density Polyethylene

摘要

It is demonstrated that the tensile drawing of high-density polyethylene (HDPE) films in the presence of physically active media via the mechanism of delocalized crazing results in the development of an open-porous structure in the polymer. Depending on tensile strain, overall volume porosity can reach -55%. Here, the parameters of the porous structure (pore and fibril diameters) are in the nanometer range. It is also demonstrated that the nanoporous structure with a highly developed surface formed via delocalized crazing is thermodynamically unstable and the related relaxation processes result in the reduction or complete elimination of porosity. Efficient ways of stabilization and preservation of open porosity and parameters of the porous structure of deformed samples of polyethylene are related to complete removal of the liquid medium from the polymer samples and annealing. This approach makes it possible to obtain open-porous materials based on polyolefins with stable characteristics, which is of a significant practical interest.