Synthesis of hetero-telechelic polymers by self-polyaddition of monomers containing both oxetanyl and carboxyl groups

The synthesis and self-polyaddition of new monomers, o-, m-, and p-[(3-ethyloxetane-3-yl)methoxyethyl]benzoic acid (o-EOMB, m-EOMB, and p-EOMB) containing both oxetanyl groups and carboxyl groups were examined. The reactions of o-EOMB, m-EOMB, and p-EOMB in the presence of tetraphenylphosphonium bromide as a catalyst in o-dichlorobenzene at 150-170 °C resulted in self-polyaddition to give the corresponding hetero-telechelic polymers poly(o-EOMB), poly(m-EOMB), and poly(p-EOMB) with Mns = 14,500-33,400 in satisfactory yields. The Mn of poly(o-EOMB) decreased at higher reaction temperatures than 150 °C, unlike those of poly(m-EOMB) and poly(p-EOMB), possibly due to inter- or intraester exchange side reactions. It was also found that the thermal properties and solubilities of these polymers were supposed with the proposed structures.