Phase structure and electrical and mechanical properties of PLLA/ionic conductive polyether blends prepared by melt mixing

Abstract

Poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) is known as an ionic conductive polymer and exhibits ionic conductivity when it forms a complex with a metal salt. In this study, poly(L-lactic acid) (PLLA)/POEGMA/poly(methyl methacrylate) (PMMA) blends were manufactured to develop high-performance polymer materials that exhibit high mechanical moduli (>1 GPa) and ionic conductivities in the semiconductive region (1.0 × 10 −9–1.0 × 10−7 cm−1) at room temperature. In addition, crystallized blends were prepared by annealing the amorphous blends and were subsequently evaluated. By mixing PLLA and the compound consisting of POEGMA and PMMA using a two-roll mill, a blend with a maximum ionic conductivity of ~1.1 × 10–7 S cm−1 was obtained. The scanning electron microscopy results indicated that the ionic conductive phases were finely dispersed within the blends. By comparing the storage modulus values of the crystallized blends to those of amorphous blends, we found that the crystallized blends were harder at approximately the glass transition temperature of PLLA. We prepared ionic conductive compound (ICC) by solution casting and the in situ polymerization of poly(ethylene glycol) methyl ether methacrylate (OEGMA) in the presence of PMMA and a cross-linking agent. Then, ionic conductive polymer blends was obtained by melt-mixing ICC and poly(L-lactic acid) (PLLA). We studied the relationship between phase structure and physical properties such as electrical and mechanical properties of the blends.