Two kinds of new polyureas 2a and 2b were synthesized by polyaddition of 1,4-phenylene diisocyanate with 2-(2-[(2-amino-4-methyl-phenoxy)methyl]allyl)oxy-5methyl-aniline (diamine 1a) and 2-[2-[(2-an-lino-4-tert-butyl-phenoxy)methyl]allyl)oxy-5tert-butyl-aniline (diamine 1b), respectively. The isobutenyl bis(aryl ether) moiety, capable of yielding plural phenolic hydroxyls by means of tandem Claisen rearrangement (TCR), was successfully incorporated into the resulting polymer main chain. TCR at isobutenyl bis(aryl ether) moieties readily occurred by heating in the bulk state, affording phenolic hydroxy groups ortho to urea linkages. Subsequent intramolecular cyclization between the hydroxy groups and the urea groups gave the bis(2-benzoxazolinone) derivatives, with loss of 1,4-phenylenediamine, resulting in degradation of the polymers. At the same time, the thermal properties were investigated by TG/DTA. The degradation of these new polymers in the bulk state was shown to proceed smoothly by heating at 230degreesC. Using a microthermal analyzer (muTA), a preliminary study of thermal patterning on polyurea. 2b film surface was carried out, and precise spot patterns were successfully processed with diameters of less than 1 mum. Two kinds of novel polyureas, containing isobutenyl bis(aryl ether) moieties ortho to the urea linkages were successfully synthesized. These results imply that these easily decomposable polymers might be used as patterning materials.