Maleate-doped high d. polyethylene and ethylene/n-octene copolymer were prepd., blended by extrusion with high d. polyethylene and processed to thin wall products with functional channels studied for their structure as well as mech. and thermal properties. The addn. of modifiers resulted in increasing the tensile, flexural and impact strengths. A small decrease in the melting temp. and small increase in the cryst. temp. were also obsd.