D 2327 (OTTO) Diphenyl ether, puriss, 99%+ Cas 101-84-8 - used as a processing aid in the production of polyesters. D 2327 (OTTO) Diphenyl ether, puriss, 99%+ Cas 101-84-8 - used as a heat transfer agent and a dye carrier. It is employed as a processing aid in the production of polyesters.