Compositions including polytetrafluoroethylene and processes for the preparation thereof

A process for producing core-shell polytetrafluoroethylene-based powder comprising polytetrafluoroethylene-based cores and styrene/acrylonitrile copolymer-based shells, the process comprising:

• a polymerisation process comprising:
• introducing an aqueous dispersion of polytetrafluoroethylene into a reactor;
• introducing an emulsifier into the reactor,;
• introducing a catalyst into the reactor;
• and
• introducing a styrene monomer, an acrylonitrile monomer, and a copolymer of styrene and acrylonitrile into the reactor, wherein the polymerisation process produces a core-shell polytetrafluoroethylene-based latex;
• wherein the polymerisation process comprises introducing between about 45% and 55% by weight of polytetrafluoroethylene, about 10% to 20% by weight of the copolymer of styrene and acrylonitrile, about 25% and 27.5% by weight of styrene monomer and about 5% and 10% by weight of acrylonitrile monomer into the reactor;
• wherein the emulsifier comprises potassium hydroxide and a mixture of oleic acid and stearic acid;
• wherein the catalyst is potassium persulfate;
• and
• a flocculation process comprising:
• introducing the core-shell polytetrafluoroethylene-based latex to a coagulant, a color stabilizer, and an antioxidant at a temperature of between about 85° C. and 90° C.;
• wherein the coagulant comprises magnesium sulfate and phosphoric acid;
• and
• increasing the temperature to between about 90° C. and 100° C. for one of facilitating and effectuating flocculation of the core-shell polytetrafluoroethylene-based latex, wherein the flocculation process produces core-shell polytetrafluoroethylene-based powder.