바이오 기반 플라스틱인 PA11과 아이오노머 블렌드의 기계적 성질

Abstract

In this study, the mechanical properties of PA11 and poly(styrene-co-styrene- sulfonic acid)(PSSA), poly(styrene-co-methacrylic acid)(PSMAA), poly(methyl methacrylate-co-methacrylic acid)(PMMA-MAA) poly(ethyl acrylate-co-acrylic acid)(PEA-AA) ionomer blends were investigated. In the first part of the work, ionomers neutralized with Na+ were blended with PA11 at 5, 10, 20, and 30 wt% contents, and the tensile strengths of the blends were measured with a Universal Testing Machine (UTM). It was seen that the shapes of the stress-strain curves of the PA11 blends were different depending on the type and content of the ionomers. In addition, for PA-EANa blends, strain hardening was observed regardless of the ionomer content. On the other hand, the Young's modulus of the PA11 blends, except for PA-EANa, increased as the ionomer content increased, and it was found that the data seemed to be fitted with Guth equation. This meant that the PA-SSNa, PA-SMNa, and PA-MMNa ionomers behaved like filler in the PA11 matrix. Moreover, the Nicolais-Narkis equation was used to evaluate the interfacial interactions between PA11 and the ionomers. As a result, it was observed that PA-SMNa and PA-MMNa had good interfacial interactions because the ionomers were well dispersed in the matrix of PA11. However, PA-SSNa and PA-EANa showed poor interfacial interactions because the ionomer themselves were aggregated in the matrix of PA11 due to strong interactions between ion pairs of the ionomers. In the second part of the work, the ionomers neutralized with Na+, Li+, and Zn2+ were blended with PA11 at the same content as in the first study, and the tensile strengths of the blends were measured. Again, it was found that PA-EAM+ underwent strain hardening even when the cation types of the ionomers were changed. In addition, the Young's modulus of the blends, except for PA-EAM+, increased regardless of the type of cations of the ionomers. This suggested that PA-SMM+, PA-MMM+, and PA-SSM+ acted as filler in the matrix of PA11 even if the cation types of the ionomers were changed. Also, as in the first study, the interfacial interactions between PA11 and the ionomers were calculated using the Nicolais-Narkis equation. It was found that the interfacial interactions were different depending on the cation types of the ionomers. In conclusion, the role of the ionomer (as filler or plasticizer) in the PA11 and ionomer blends depended on the ionomer type. On the other hand, the strengths of the interfacial interactions between the two polymers in the blend depended on the cation type of the ionomers. Finally, it was found that the PA-SMNa(30) blend was a blend that could utilize the advantages of ionomer while maintaining the mechanical properties of PA11 (strain, stress, Young's modulus, interfacial interaction) to some extent.