Synthesis, Characterization and Bulk Properties of Amphiphilic Copolymers Containing Fluorinated Methacrylates from Sequential Copper-Mediated Radical Polymerization

ABSTRACT: The partly fluorinated monomers, 2,2,2-trifluoroethyl methacrylate (3FM), 2,2,3,3,4,4,5,5-octafluoropentyl methacrylate (8FM), and 1,1,2,2-tetrahydroperfluorodecyl methacrylate (17FM) have been used in the preparation of block copolymers with methyl methacrylate (MMA), 2-methoxyethyl acrylate (MEA), and poly(ethylene glycol) methyl ether methacrylate (PEGMA) by Atom Transfer Radical Polymerization.

A kinetic study of the 3FM homopolymerization initiated with ethyl bromoisobutyrate and Cu(I)Br/N-(n-propyl)-2-pyridylmethanimine reveals a living/ controlled polymerization in the range 80-110 °C, with apparent rate constants of 1.6 . 10-4 S-l to 2.9 . 10-4 S-l. Various 3FM containing block copolymers with MMA are prepared by sequential monomer addition or from a PMMA macroinitiator in all cases with controlled characteristics.

Block copolymers of 3FM and PEGMA resulted in block copolymers with PDI <1.22, whereas block copolymers from 3FM and MEA have less controlled characteristics. The block copolymers based on MMA with 8FM and 17 FM have PDI's <1.30. The glass transition temperatures of the block copolymers are dominated by the majority monomer, as the sequential monomer addition results in too short pure blocks to induce observable microphase separation.

The thermal stability of the fluorinated poly((meth)acrylate)s in inert atmosphere is less than that of corresponding nonfluorinated poly((meth)acrylate)s. The presence of fluorinated blocks significantly increases the advancing water contact angle of thin films compared to films of the nonfluorinated poly((meth)acrylate)s.