Fluorine-containing polymers and preparation and use thereof

Abstract

Group IV organometallic compounds, e.g. alkylsilane, or alkylsiloxane compounds, are used as chain tranfer agent in the radical initiated polymerization of ethylenically unsaturated monomers, to give polymers comprising non-ionic end groups.

What is claimed is: 
     
       1. A fluorine-containing polymer comprising a fluorine-containing, saturated, carbon-carbon backbone chain comprising interpolymerized units derived from a fluorine-containing ethylenically unsaturated monomer, and an organometallic group, derived from a non-free-radically polymerizable organometallic compound, comprising .[.a.]. .Iadd.1 to 10 .Iaddend.silicon .[.atom.]. .Iadd.atoms .Iaddend.and an aliphatic carbon atom bonded directly to .Iadd.one of .Iaddend.said silicon .[.atom.]. .Iadd.atoms.Iaddend.. 
     
     
       2. The polymer of claim 1 wherein said backbone chain consists essentially of interpolymerized units derived from ethylenically unsaturated monomer. 
     
     
       3. The polymer of claim 1 wherein said fluorine-containing monomer is selected from the group consisting of vinylidene fluoride, hexafluoropropene, chlorotrifluoroethylene, 2-chloropentafluoropropene, perfluoroalkyl vinyl ethers, tetrafluoroethylene, 1,1-hydropentafluoropropene, 2-hydropentafluoropropene, vinyl fluoride, dichlorodifluoroethylene, perfluorodiallylether, trifluoroethylene, 1,1 -dichlorofluoroethylene, and perfluoro-1,3-dioxoles of formula ##STR4## where each R f  is F, C n  F 2n+1  where n is from 1 to 4, or where the two R f  groups together with the carbon atom to which they are attached form a ring of formula C n  F 2n-2  where n is from 5 to 8. 
     
     
       4. The polymer of claim 1 wherein .[.said organometallic group comprises from 1 to 200 silicon atoms and wherein .]. said silicon atoms are bonded directly to each other or through an alkylene group, arylene group, sulfur atom, oxygen atom, phosphorus atom, nitrogen atom, or combinations thereof. 
     
     
       5. The polymer of claim 4 wherein said organometallic group is silyl, silazyl, or siloxyl. 
     
     
       6. The polymer of claim 4 wherein said organometallic group has the formula   R--[(R).sub.2 M].sub.z --[(Q).sub.x --M(R).sub.2 ].sub.y --     M is silicon, Q is a divalent linking group, each R is independently H, alkyl, aryl, or combinations thereof, x is 0 or 1, z is 0 or 1, y is an integer from 1 to 9.   
     
     
       7. The polymer of claim 5 wherein said carbon-carbon backbone chain consists essentially of interpolymerized units derived from one or more monomers selected from the group consisting of tetrafluoroethylene, hexafluoropropene, vinylidene fluoride, chlorotrifluoroethylene, ethylene, propylene, perfluoromethyl vinyl ether, and perfluoropropylvinyl ether. 
     
     
       8. The composition of claim 6 in its cured state. 
     
     
       9. A shaped article comprising the polymer of claim 1.