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

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 degrees 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. (c) 2019 Society of Chemical Industry