PERMEABILITY OF COATINGS MADE WITH EMULSIFIED POLYETHYLENE WAX

Emulsions of polyethylene wax (oxidized polyethylene) were coated onto highly permeable film. Gas permeability of the dried coating was determined from measurements of permeance and coating thickness. With oleic acid and morpholine used as emulsifiers, water vapor permeability of a high-density polyethylene wax coating was 1.7-3.2 g mil/(m2 day mmHg) depending on the relative humidity gradient. For the same coating the respective O2 and CO2 permeabilities of the coating at 30-degrees-C were 34 000 and 135 000 mL (STP) mil/(m2 day atm). In general, coatings made from polyethylene wax have values of O2 and CO2 permeability that are high compared to those of most other polymers.