Orientation of pores in microporous polyethylene films as determined by polarized absorption spectroscopy

Microporous polyethylene films with good mechanical properties can be produ ced on the basis of hard-elastic specimens by uniaxial deformation. The so called "guest-host" effect [1, 2] was explored to determine the order param eter of pores in a series of PE membranes so produced by polarized absorpti on spectroscopy using dichroic dyes dissolved in the nematic liquid crystal ZLI 1840 (LC) as indicator. The parameter of the orientation order S-A of the pores along the draw direction was found to increase with increasing sp in draw. A qualitative comparison of S-A with the thermodynamic behavior of the dye + LC systems confined in the pores was made. The results obtained are related to the mechanism of porous structure formation.