In order to investigate synthetic route of polyperfluorotriazine elastomer, 2-trifluoromethyl4,6-bis(4′-iodo-2′-oxahexafluorobutyl)-1,3,5-triazine (1), a novel triazine monomer, was synthesized from 5-iodo-3-oxa-octafluoropentanesulfonyl fluoride (2) in eight-steps. 2 was reduced by potassium sulfite to the sulfinate (3), which was treated with hydriodic acid to yield 5-iodo-3oxa-hexafluoropentanoic acid (4). Compound 4 was transformed to 5-iodo-3-oxa-hexafluoropentanenitrile (7) through the corresponding ester 5 and amide 6.The desired product 1 was prepared by acylation-cyclodehydration of the imidoylamidine 9,obtained by condensation of the nitrile 7 with the amidine 8. The various methods for the esterification of perfluorocarboxylic acid were studied and a possible mechanism for the transformation of perfluorosulfinate to the corresponding perfluorocarboxylic acid by hudriodic acid was proposed.Crude 1 contained compounds6,11,13 as impurities which were removed by low temperature crystallization followed by filtration through a short alumina column.The monomer 1 was polymerized by UV-irradiation in the presence of Hg with or without solvent.Polyperfluorooxaalkyl triazine 17 thus obtained showed good thermal stability.In the main chain of the polymer there was no weak unit of the uncyclized ring.Polymer 17 had an average molecular weight of ca.1.33—2.0×104(D.P=27—42) and the temperature of 10% weight loss in nitrogen was 340℃.