Polymer, Vol.37, No.21, 4689-4693, 1996
The Influence of Coalescence on the Morphology of the Minor Phase in Melt-Drawn Polyamide-6/HDPE Blends
The influence of coalescence on the final state of elongation of the dispersed phase in polyamide-6/HDPE blends was studied. The blends were prepared by ribbon extrusion and melt drawn at different draw ratios in order to obtain a high variation in the state of fibrillation of the minor phase. In order to separate out the relative role of single particle deformation and coalescence in determining the final morphology, coalescence was suppressed by two techniques. Firstly, coalescence was diminished to a small effect by studying the behaviour of the blend containing only 1 vol% polyamide-6 (PA-6). In the other case coalescence was suppressed in a blend containing 20 vol% PA-6 by adding an interfacial modifier. The results indicate that the form factors for 1% PA-6/HDPE and 20% PA-6/HDPE (compatibilized) are identical over a wide range of hot stretch ratios and the final state of elongation is dominated entirely by single particle deformation phenomena. The 20% PA-6/HDPE (uncompatibilized) system displays an added strong contribution of coalescence to the final morphology. The relative contribution of coalescence and single particle deformation in influencing the final morphology in this latter system can be inferred quantitatively from these results.