High‐performance soluble copolyarylate based on phenolphthalein: synthesis, characterization and properties

Abstract

Abstract A series of copolyarylates (PP0–PP100) containing phthalide groups was synthesized via interfacial polymerization from a mixture of phenolphthalein (PP) and bisphenol A with molar equivalent of terephthalyl chloride. Incorporating PP into the polymer chain improved the solubility of the polyarylates in common organic solvents. The glass transition temperature (191–314 °C), residual weight percentage, Young's modulus (1.7–2.8 GPa), solubility and complex melt viscosity of the copolyarylates increased with increasing PP units in the copolymerization. By contrast, crystallinity and elongation at break (14.1 to 11.2%) of the copolyarylates decreased with increasing PP units in the polymer backbone. When the PP content increased over 30 mol% (PP30), the copolyarylates became amorphous polymers. When the PP content was below 30 mol%, the copolyarylates exhibited good melt processability. With regards to its solubility, thermal stability, mechanical properties and melt processability, PP30 may be considered as a promising candidate in the field of processable high‐performance engineering plastics. © 2019 Society of Chemical Industry