Photochemical modification of some polynaphthalimides

A series of polynaphthalimdes from dinaphthalene dianhydride and aromatic d iamines mainly with alkyl substituents at ortho position to amine groups al ong with the model compounds has been synthesized using one-step high tempe rature polycondensation. It was found that in the case of the model compoun ds and the polymers synthesized from diamines with alkyl groups having at a carbon two hydrogen atoms, cyclodehydration process can take place during heating or UV irradiation and formation of additional cycle of pyrrole stru cture was observed. The polynaphthalimides synthesized from aromatic diamin es substituted with alkyl groups can be modified under heating or UV irradi ation, towards additional ring formation of pyrrole type, which causes an i ncrease of the polymers glass transition temperatures.