Processing of Thermotropic Fully Aromatic Polyesters by Powder Molding Accompanied by Solid-State Post-Polymerization

Thermotropic polyesters are a subject of keen interest due to their exceptional heat resistance, thermal stability, and high strength. However, these thermal characteristics pose significant constraints on standard manufacturing processes, as the melting temperatures of these polymers can exceed 300 °C. This study explored the feasibility of manufacturing final items molded from prepolymers through a solid-state polymerization process. A copolymer composed of 4-acetoxybenzoic acid (4ABA), 3-acetoxybenzoic acid (3ABA), and 4'-acetoxybiphenyl-4-carboxylic acid (ABCA) was synthesized using melt polycondensation. To comprehensively evaluate the performance of the resulting material, several sets of samples were prepared, including those containing TiO₂. Experimental samples from the pre-polymers were obtained through injection molding followed by high-temperature solid-state post-polymerization. The final products underwent a range of tests, including rheological and mechanical analyses, as well as thermal evaluations. The products demonstrated sufficient strength and stability. The proposed method of solid-state post-condensation offers significant potential advantages for the practical application of manufacturing high-performance engineering materials.