NEW MATERIAL:Perfluoropolyether diacrylate of formula I (R1, R2 are H, methyl; 1 is 2W4; m, n are integers satisfying the relation of 1≤m+n≤50).

EXAMPLE: The compound of formula II.

USE: A monomer giving readily wettable transparent polymers having excellent gas permeability, chemical resistance and strength.

PREPARATION: The addition reaction of hexafluoropropylene oxide to perfluorodicarboxylic fluoride of formula III is effected in the presence of an anion to give a perfluoropolyether bearing carboxylic fluorides groups on both chain ends. Then, the product is allowed to react with an acrylate having terminal hydroxyl groups to give perfluoropolyether diacrylate of formula I.