The influence of blend composition on the properties of LDPE-PA6-EVAL-blends

The aim of this work was to investigate the effects of the composition on the properties of LDPE-PA6-EVAL blends with an emphasis on the influence of the EVAL grade on the system. Furthermore, also the effects of additional compatibilization by maleic anhydride grafted PE on the blend properties should be investigated. We found, that EVAL has some compatibility with PA6, as long as the vinyl alcohol content is high enough, in this case at least 62 mol%. This results, in combination with the high shear intensity applied, in a fine dispersed morphology and reasonable properties. In case of the non-compatible EVAL grade, the addition of MAPE improves the properties like impact strength and elastic modulus, which can also be seen from the morphology of the samples. The addition of a compatibilizer also shows an expectable stabilization effect, which can be seen by comparing the morphology of the extruded melt strands after compounding with the morphology of the injection molded specimen afterwards. In conclusion this shows that with compatibilisation, the blend properties are stable and sufficient for various applications, therefore such blends could be reused for another life cycle.