Influence of ZnSt2 on structure of acrylate-based ionomers with different lanthanide (La(III)) ion and acid contents

A series of acrylate processing aid (ACR)-based ionomers with different lanthanide (La(III)) ion and acid contents were synthesized, and the interaction between ionomer and zinc stearate (ZnSt(2)) was investigated immediately after thermally annealing the ionomer/ZnSt(2) (3/1 in weight) mixtures at 180A degrees C. The results revealed that the ion groups in ionomer have a strong interaction with ZnSt(2). The annealed mixtures contained hot alcohol extractable and unextractable ZnSt(2). The melting of ZnSt(2) and the thermal behavior of the ionomer in the annealed mixtures were seriously influenced by the contents of La(III) and acid in the ionomers. The ionomer containing 0.25 mmol/g acid and 0.37 mmol/g La(III) has a detectable cluster phase. Annealing its ZnSt(2) mixture could break down the cluster phase and lower glass transition temperature of the ionomer matrix. However, washing away the extractable ZnSt(2) led to the reappearance of the cluster transition temperature and return of the glass transition temperature of matrix to the original position.