Barrier properties of polyamide-6/high density polyethylene blends

The barrier properties of Polyamide-6 (PA6)/High Density Polyethylene (HDPE ) blends with and without compatibilizer prepared by ribbon extrusion were studied. The results show that the toluene diffusivity was improved by the addition of an interfacial agent and by inducing orientation of the polymer chains. The presence of PA-6 in the blend results in a decrease of the tol uene diffusivity. This reduction is even larger for the case of the interfa cial modified system. However, the most important reduction of the toluene diffusivity is observed for pure HDPE when stretched. A six-fold decrease i s observed when the draw ratio is increased two fold. In the case of the pe rmeability of different solvents through blends a gravimetric permeation ce ll was used. The results show that thr permeability decreases with increasi ng size of the penetrant molecules (CH2Cl2, CHCl3 and CCl4) and this decrea se is more important for a compatibilized blend.