New generation of photosensitive poly(azomethine)esters: Thermal behaviours, photocrosslinking and photoluminescence studies

Three new series of soluble photosensitive poly(azomethine)esters with even methylene spacers in their backbone and various substituents on their side chain were synthesized. Their molecular structures were elucidated with various spectroscopic methods. The different substituents and length of the methylene spacers were found to influence the thermal stability of the polymers. The –OCH3 substituted side chain poly(azomethine)esters showed highest thermal stability, followed by –Cl and –H. Meanwhile, poly(azomethine)esters with longer methylene spacers exhibited lower thermal stability. The photoreactivity of these poly(azomethine)esters revealed that the chalcone moiety dimerized and led to photocrosslinking. The rate of photocrosslinking increased with longer methylene spacers and in the order of –H