형상기억 Poly(oxyethylene-b-butylene adipate) Ionomer의 상전이 거동

Abstract

A series of biodegradable poly(oxyethylene-b-butylene adipate) ionomers (POBAis) were prepared by two step polymerization of adipic acid, 1,4-butanediol and mixed monomers of sodium sulfonated poly(ethylene oxide) (SPEO). The chemical compositions of these POBAis were ascertained by 1H-NMR spectroscopy. We investigated the strain-induced phase transition at the transition temperature during the shape deformation and recovery process using the wide angle X-ray analysis (WAXD). It is confirmed that α-form crystal formed by drawing does not turn back to the ones of initial state during recovery process because the monoclinic α-form crystal is structurally more stable than the orthorhombic β-form crystal. It was observed that POBA5.0i showed a good shape memory effect than that of other samples due to physical cross-linking by ionic group.