Co-cured blends of fluoroelastomers of tetrafluoroethylene-propylene copolymer with cure site monomer and terpolymers of Vinylidene fluoride (VDF), Hexafluoropropylene (HFP) and Tetrafluoroethylene (TFE) with peroxide as initiator and coagent TAIC as crosslinker show improved curing performance, improved mechanical properties and improved compression set as well. The co-cured fluoroelastomers show improved chemical resistance to the solvent aging systems and better retention of mechanical properties after aging at high temperature in the solvents system.

Co-cured blends of fluoroelastomers of tetrafluoroethylene-propylene copolymer with cure site monomer and terpolymers of Vinylidene fluoride (VDF), Hexafluoropropylene (HFP) and Tetrafluoroethylene (TFE) with peroxide as initiator and coagent TAIC as crosslinker show improved curing performance, improved mechanical properties and improved compression set as well. The co-cured fluoroelastomers show improved chemical resistance to the solvent aging systems and better retention of mechanical properties after aging at high temperature in the solvents system.

Copolymers of one or more halogenated olefins and one or more halogenated co-monomers selected from the group consisting of halogenated alkenyl ethers, halogenated alkenyl esters, and halogenated (meth)acrylates are useful in various end-use applications wherein the presence of halogen (e.g., fluorine) in the copolymer imparts one or more desirable properties, as compared to analogous copolymers not containing halogen.

An elastomeric fluoropolymer includes the following monomer units: about 45 mol % to about 65 mol % —CF.sub.2—CH.sub.2—; about 8 mol % to about 30 mol % —CF.sub.2—CF.sub.2—; about 4.5 mol % to about 25 mol % —CF.sub.2—CF(O—CF.sub.3)—; and about 6 mol % to about 20 mol % —CF.sub.2—CF(O—CF.sub.2—CF.sub.2—O—(CF.sub.2—O).sub.n—CF.sub.3)—, where n is 1 or 2. In some embodiments, a composition includes an elastomeric fluoropolymer and at least one additive. In some embodiments, a composition includes a first elastomeric fluoropolymer and a second elastomeric fluoropolymer blended with the first elastomeric fluoropolymer. The first elastomeric fluoropolymer includes the following monomer units: about 45 mol % to about 65 mol % —CF.sub.2—CH.sub.2—; about 8 mol % to about 30 mol % —CF.sub.2—CF.sub.2—; about 4.5 mol % to about 25 mol % —CF.sub.2—CF(O—CF.sub.3)—; and about 6 mol % to about 20 mol % —CF.sub.2—CF(O—CF.sub.2—CF.sub.2—O—(CF.sub.2—O).sub.n—CF.sub.3)—, where n is 1 or 2.

Co-cured blends of fluoroelastomers of tetrafluoroethylene-propylene copolymer with cure site monomer and terpolymers of Vinylidene fluoride (VDF), Hexafluoropropylene (HFP) and Tetrafluoroethylene (TFE) with peroxide as initiator and coagent TAIC as crosslinker show improved curing performance, improved mechanical properties and improved compression set as well. The co-cured fluoroelastomers show improved chemical resistance to the solvent aging systems and better retention of mechanical properties after aging at high temperature in the solvents system.

Co-cured blends of fluoroelastomers of tetrafluoroethylene-propylene copolymer with cure site monomer and terpolymers of Vinylidene fluoride (VDF), Hexafluoropropylene (HFP) and Tetrafluoroethylene (TFE) with peroxide as initiator and coagent TAIC as crosslinker show improved curing performance, improved mechanical properties and improved compression set as well. The co-cured fluoroelastomers show improved chemical resistance to the solvent aging systems and better retention of mechanical properties after aging at high temperature in the solvents system.

The invention relates to fluoropolymers that have been modified with low molecular weight, polymeric chain transfer agents, and uses of the modified fluoropolymers. The modified fluoropolymers provide enhanced properties to the fluoropolymer, such as increased adhesion, and hydrophilic characteristics. The modified functional fluoropolymers are useful in many applications, including as binders in electrode-forming compositions and separator compositions, for hydrophilic membranes and hollow fiber membranes, as an aqueous and a solvent cast coating for baked decorative and protective coatings, and as a tie layer between a fluoropolymer layer and an incompatible polymer layer.

The invention relates to an extrusion-assisting agent containing low-viscosity thermoplastic fluorinated polymers and preferably not containing a synergist. The invention also relates to the use of the extrusion agent for extrusion in the form of monofilament or multifilament fibres or non-woven materials, and to the extrusion method.

The invention relates to a method of polymerizing at least one monomer comprising a vinylidene fluoride monomer, the method comprising putting in contact the at least one monomer with a polymerization initiator -and an oxidizing agent, the polymerization initiator having the formula (I):

##STR00001##

wherein R.sub.f is a fluoroalkyl group comprising from 1 to 3 carbon atoms; and M.sup.x+ is chosen from a monovalent cation, or a divalent cation, or a trivalent cation, or a tetravalent cation.

The invention relates to a method of polymerizing at least one monomer comprising a vinylidene fluoride monomer, the method comprising putting in contact the at least one monomer with a polymerization initiator -and an oxidizing agent, the polymerization initiator having the formula (I):

##STR00001##

wherein R.sub.f is a fluoroalkyl group comprising from 1 to 3 carbon atoms; and M.sup.x+ is chosen from a monovalent cation, or a divalent cation, or a trivalent cation, or a tetravalent cation.