Strong Attractive Interaction between Ethylene Ionomer and Carboxyl Groups of Styrene-Co-Methacrylic Acid

Abstract

Effects of styrene-co-methacrylic acid (StMAA) on melt viscosity and morphology for ethylene ionomer were studied. In this study, we used poly-(ethylene-co-methacrylic acid) of neutralization degree 54 % with sodium ions (EMAA54Na). Dynamic viscoelasticity of EMAA-54Na/polystyrene(PS) or EMAA-54Na/StMAA blends was evaluated. EMAA54Na/StMAA blends differed from EMAA-54Na/PS blends in rheological property. Zero shear viscosity η 0 of EMAA54Na/StMAA was higher than expected viscosity with increasing contents of StMAA. Furthermore, fall down of the damping function obtained from stress relaxation measurement of EMAA-54Na/StMAA was weaker than that of EMAA54Na. These results indicated strong interaction between EMAA ionomer and carboxyl groups of StMAA. Results of morphological observation and Fourier transform infrared spectroscopy also indicated that the strong interaction is attractive.

Self‐healing polymer blend based onPETGandEMAA

“…observed a similar morphology in polypropylene (PP)/ethylene vinyl acetate (EVA) blends processed under co‐rotating twin‐screw extrusion, where EVA segregated into spherical domains embedded inside a co‐continuous PP phase. Nishioka 37 . also observed similar morphology in blends of ionomers EMAA and methacrylic acid styrene (SMAA).…”

“…Nishioka. 37 also observed similar morphology in blends of ionomers EMAA and methacrylic acid styrene (SMAA). This author observed spherical domains of EMAA into the SMMA matrix after the use of tetrahydrofuran to extract EMAA and attributed the morphology to the strong interactions of EMAA and the carboxylic groups present in SMAA.…”

“…For neat EMAA an endothermic transition has been reported in the range of 40–60 °C, 21 which has been ascribed to the order and disordering temperature (T I ) of ionic clusters present in the ionomer structure, Figure 3 (a). This transition is engaged with the disorder of quasi‐crystalline domains or cross‐linked regions of restricted mobility containing hydrogen bonds or stronger ionic interactions 21,37 . It is known that the presence of T I is not clear if the material is heated above the first melting temperature of the ionomer (T mI ) and then rapidly cooled and heated again.…”

“…This transition is engaged with the disorder of quasi-crystalline domains or cross-linked regions of restricted mobility containing hydrogen bonds or stronger ionic interactions. 21,37 It is known that the presence of T I is not clear if the material is heated above the first melting temperature of the ionomer (T mI ) and then rapidly cooled and heated again. Accordingly, this phenomenon can be observed by comparing the DSC curves of neat EMAA in the first heating and in the second heating.…”