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)-multiblock copoly(ester imide)s based on N-(3'-hydroxyphenyptrimellitimide (IM), 4-hydroxybenzoic acid (HBA), and 6-hydroxy-2-naphthoic acid (HNA) were investigated as single-component high-temperature (>= 250 degrees C) shape memory polymers (SMPs). A high T-g (similar to 200 degrees C) HBA/IM block embedded in a low T-g (similar to 120 degrees C) HBA/HNA matrix creates a stable rubbery plateau that can be extended to similar to 240 degrees C by cross-linking. The shape fixation (Rf) and shape recovery efficiency. (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 similar to 100%) at 170 degrees C. After cross-linking the thermoplastic films a single component system as obtained that exhibited high-temperature (>= 250 degrees C) tunable triple SM and one-way reversible SM behavior.