Difunctional oligomers of perfluoro(methyl vinyl ether)

Abstract

Oligomers of perfluoro(methyl vinyl ether) with vinylidene fluoride or tetrafluoroethylene are disclosed that contain 40-90 mole percent copolymerized units of vinylidene fluoride or tetrafluoroethylene and 10-60 mole percent copolymerized units of perfluoro(methyl vinyl ether), said oligomers having two functional endgroups and having a number average molecular weight between 1000 and 25,000.

1 . A process for making an oligomer, said process comprising:
 A) introducing into a reactor tetrafluoroethylene, perfluoro(methyl vinyl ether) and a chain transfer agent of the formula I—Rf-I, wherein Rf is a perfluoroalkylene group or an oxygen atom-containing perfluoroalkylene group containing between 3 and 12 carbon atoms; and   B) polymerizing said tetrafluoroethylene and perfluoro(methyl vinyl ether) to form an oligomer consisting essentially of i) 40 to 90 mole percent copolymerized units of tetrafluoroethylene; and ii) 10 to 60 mole percent copolymerized units of perfluoro(methyl vinyl ether);   
       wherein said oligomer has a number average molecular weight of 1000 to 25,000 g/mole, a molecular weight distribution less than 1.5, and wherein said oligomer has an iodine atom functional group at each chain end. 
     
     
         2 . The process of  claim 1  wherein said oligomer has a number average molecular weight of 1500 to 5,000 g/mole. 
     
     
         3 . The process of  claim 1  wherein in step A) hexafluoropropylene is further introduced into said reactor and polymerized in step B). 
     
     
         4 . The process of  claim 1  wherein in step A) a perfluoro vinyl ether of formula CF 2 ═CFO(R f′ O) n (R f″ O) m R f , where R f′  and R f″  are different linear or branched perfluoroalkylene groups of 2-6 carbon atoms, m and n are independently 0-10, and R f  is a perfluoroalkyl group of 1-6 carbon atoms is further introduced into said reactor and polymerized in step B). 
     
     
         5 . The process of  claim 1  wherein in step A) a functional fluorovinyl ether is further introduced into said reactor and polymerized in step B), said functional fluorovinyl ether selected from the group consisting of i) propanoic acid, 3-[1-[difluoro[(1,2,2-trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-2,2,3,3-tetrafluoro-, methyl ester; ii) ethanesulfonyl fluoride, 2-[1-[difluoro[(1,2,2-trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-1,1,2,2-tetrafluoro-; iii) 1-propanol, 3-[1-[difluoro[(trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-2,2,3,3-tetrafluoro-; iv) propanenitrile, 3-[1-[difluoro[(1,2,2-trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-2,2,3,3-tetrafluoro-; v) hexanenitrile, 2,2,3,3,4,4,5,5,6,6-decafluoro-6-[(1,2,2-trifluoroethenyl)oxy]-; vi) propanenitrile, 2,3,3,3-tetrafluoro-2-[1,1,2,2,3,3-hexafluoro-3-[(trifluoroethenyl)oxy]propoxy]-; vii) propanamide, 3-[1-[difluoro[(1,2,2-trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-2,2,3,3-tetrafluoro-; viii) 1-propanol, 3-[1-[difluoro[(trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-2,2,3,3-tetrafluoro-, dihydrogen phosphate; and ix) propanoic acid, 3-[1-[difluoro[(trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-2,2,3,3-tetrafluoro-.