화학공학소재연구정보센터
Macromolecules, Vol.46, No.19, 7845-7852, 2013
Shape Memory Behavior of a Polyethylene-Based Carboxylate Ionomer
Shape memory behavior of a partially zinc-neutralized, poly(ethylene-co-methacrylic acid) ionomer was investigated. The ionomer was a semicrystalline ionomer with a broad melting transition in the range 60-100 degrees C. Physical crosslinlcs in the ionomer due to an ionic nanodomain structure provided a "permanent" crosslinked network, while polyethylene crystallinity provided a temporary network. The broad melting transition allowed one to tune the dual-shape memory behavior by choosing a switching temperature, T, anywhere within the melting transition. Similarly, multiple-shape memory behavior was achieved by choosing two or more switching temperatures within the melting transition, though the effectiveness of fixing (F) depended on how much material was melted and recrystallized to support the specific temporary shape. Crosslinking improved the recovery efficiency (R), and the crosslinked ionomer exhibited nearly ideal shape memory behavior in the dual-shape memory cycle.