Synthesis, properties and thermal degradation mechanism of bisphenol A-based polyarylates capped with p-tert-butylphenol

A series of bisphenol A-based polyarylates was synthesized by using 2,2-bis (4-hydroxyphenyl) propane (BPA), terephthaloyl dichloride (TPC), and isophthaloyl dichloride (IPC) as raw materials and p-tert-butylphenol as a capping agent through interfacial polymerization to investigate the effect of end group structure on polymer properties. And the polymer films could be obtained by solvent casting method. The successful introduction of p-tert-butylphenol into the backbone adjusted molecular masses and achieved a regulable improvement of the polymer’s thermal properties. The thermal mass loss 5% temperature of the polymers raised above 470 °C, which indicated the thermal properties were broadly in line with that of the commercial product U-100. Besides, the addition of capping agent also improved the light transmission of the polymers and the transmittance reached above 83% at a wavelength of 450 nm. In addition, the thermal degradation mechanism of polyarylate and U-100 was investigated by simultaneous thermal analysis (STA)-IR and Py/GC–MS. It was discovered that PAR decomposed thermally at their end groups and ester groups first, followed by the breakage of their carbon–carbon bonds, which coincided with U-100’s thermal degradation mechanism. The thermal degradation mechanism of bisphenol A-based polyarylates was proposed. Graphical abstract