High-Temperature Shape Memory Behavior of Novel All-Aromatic (AB)n-Multiblock Copoly(ester imide)s

Thermoplastic and thermoset all-aromatic liquid crystal (LC) (AB) n -multiblock copoly(ester imide)s based on N -(3′-hydroxyphenyl)trimellitimide (IM), 4-hydroxybenzoic acid (HBA), and 6-hydroxy-2-naphthoic acid (HNA) were investigated as single-component high-temperature (≥250 °C) shape memory polymers (SMPs). A high T g (∼200 °C) HBA/IM block embedded in a low T g (∼120 °C) HBA/HNA matrix creates a stable rubbery plateau that can be extended to ∼240 °C by cross-linking. The shape fixation ( R f ) and shape recovery efficiency ( R r ) of the thermoplastic and thermoset films were investigated using a rheometer in torsion mode. Thermoplastic LC copoly(ester imide) films showed excellent dual SM behavior ( R f and R r ∼ 100%) at 170 °C. After cross-linking the thermoplastic films a single component system as obtained that exhibited high-temperature (≥250 °C) tunable triple SM and one-way reversible SM behavior.