Influence of surlyn ionomer compatibilizer on phase morphology, crystallization behavior and thermal stability of PA6/surlyn /LDPE blends

Abstract

PA6/LDPE blends exhibit phase separation morphology so compatibilization is needed to improve the interfacial adhesion between the phases. In this work, blends of PA6 and LDPE were prepared using a Surlyn ionomer as a compatibiliaer. This ionomer type consisted of ethylene segments similar to LDPE structure, and carboxylic groups that are capable of reacting with amide end groups of PA6. This study focused on the effects of Surlyn content on phase morphology, crystallization behavior, and thermal stability of PA6/LDPE blends. The effects were investigated using scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and wide-angle X-ray diffraction. PA6/Surlynand Surlyn/LDPE were also studied in order to get a better understanding of PA6/LDPE/Surly blends. Surlyn was shown to be an effective compatibilizer for PA6/LDPE blends as evidenced by a reduction in dispersed phase size and an increase in thermal stability compared with that values derived from a simple rule of mixing. These results were attributed to : the chemical interaction between PA6 and Surlyn; the effect of Surlyn on LDPE in the amorphous phase, despite the absence of co-crystallization of Surlyn and LDPE; the effect of zinc ions from the Surlyn. It was also found that at a PA6/LDPE blend ratio of 80/20, with 1.5 and 5.0 phr Surlyn, the materials had similar degradative properties to that of PA6, thus providing an economically viable way to produce a new material with excellent thermal properties at low cost.