Ionomer Compatibilised PA6/EVA Blends
ARUP RANJAN BHATTACHARYYA, ANUP K. GHOSH, ASHOK MISRA
Institute of Polymer Research Dresden
Germany

Keywords: Compatibilisation, Ionomer, PA6/EVA blends

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The development of new multiphase polymeric materials with desired mechanical properties often involves the strategy of blending. Blends of polyamide6 (PA6) and ethylene vinyl acetate (EVA) are immiscible in nature [1]. An attempt has been made to improve the phase morphology of PA6/EVA blends by introducing an ionomer as a compatibiliser. The blending was carried out in a co-rotating, intermeshing twin screw extruder (ZSK25, L/D=46). The compatibilisation of PA6/EVA blends with the addition of an ionomer on the mechanical properties (impact strength and tensile properties) and morphology were studied as a function of ionomer concentration with the primary aim of enhancing impact strength. The level of EVA forming the dispersed phase was kept at 20 wt.% and the ionomer content was varied from 0 to 1.6 wt.%. The morphological characterisation was carried out by scanning electron microscopy (SEM) to analyse the dispersed phase size and also to investigate the impact fractured surface.

It was found that notched Izod impact strength of PA6/EVA/ionomer blends increased with the incorporation of ionomer to about three times that of uncompatibilised PA6/EVA blends. Further, it was observed that on incorporation of the ionomer the tensile strength also increased significantly. SEM studies of cryogenically fractured surfaces indicated a decrease in dispersed phase domain size with addition of ionomer, while the impact fractured surfaces of PA6/EVA blends indicated extensive deformation with the formation of rumples indicating increased interfacial adhesion as compared to PA6/EVA blends. An attempt has been made to evaluate the compatibilising efficiency of ionomer in PA6/EVA blends.
Reference
1. Bhattacharyya AR, Maiti SN and Misra A. J Appl Polym Sci 2002;85:1593.