Synthesis and characterization of new aromatic polyesters with a (4-phenoxyphenyl)phenylmethene linkage

A series of new aromatic polyesters containing a (4-phenoxyphenyl)phenylmethene linkage were prepared by phase transfer-catalyzed interfacial polycondensation of 1,1-bis(4-hydroxyphenyl)-1-(4-phenoxyphenyl)-1-phenylmethane with terephthaloyl chloride, isophthaloyl chloride, and so on. The inherent viscosities of the polyesters ranged from 0.62 to 0.90 dL/g, while number-average molecular weights were in the range of 30,500–35,500 g/mol. All the polyarylates were readily soluble in organic solvents such as dichloromethane, chloroform (CDCl₃), tetrahydrofuran, meta-cresol, pyridine, N,N-dimethylformamide, N,N-dimethylacetamide, and 1-methyl-2-pyrrolidinone at room temperature, and could be cast into tough, transparent, and flexible films from their CDCl₃ solutions. Wide-angle X-ray diffraction measurements revealed the amorphous nature of the polyarylates. These polymers showed glass transition temperatures (T _gs) between 178°C and 240°C and decomposition temperatures at 10% weight loss ranging from 446°C to 483°C, while the initial degradation temperatures in the range of 410–435°C under nitrogen atmosphere. These new polyarylates exhibited higher T _gs and better solubility than bisphenol A-based analogues.