Barrier properties of polyamide-6/high density polyethylene blends

SUMMARY

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 toluene diffusivity. This reduction is even larger for the case of the interfacial modified system. However, the most important reduction of the toluene diffusivity is observed for pure HDPE when stretched. A six-fold decrease is observed when the draw ratio is increased two fold. In the case of the permeability of different solvents through blends a gravimetric permeation cell was used. The results show that the permeability decreases with increasing size of the penetrant molecules (CH₂Cl₂, CHCl₃ and CCl₄) and this decrease is more important for a compatibilized blend.