Abstract: A porous polymeric sheet is provided having an electrostatic charge and comprising a zero-three composite of a polymeric matrix and a ferroelectric material dispersed therein. The polymeric component comprises a non-polar thermoplastic polymer, such as a polyolefin, and a second thermoplastic polymer having polar functional units, such as a telomer. The composite material is formed into a porous sheet and is electrically or corona poled to create an electret material which is well suited four use in various filtration, air-masking and dust wipe applications.

Abstract: A fiber which includes a thermoplastic polymer and particles of a ferroelectric material dispersed therein. The thermoplastic polymer may be, for example, a polyolefin, such as polypropylene or polyethylene, and the ferroelectric material may be barium titanate. The ferroelectric material may be present at a level of from about 0.01 to about 50 percent by weight (from about 0.001 to about 13 percent by volume), and will have a longest dimension in a range of from about 10 nanometers to about 10 micrometers. The fiber may be exposed to an electric field. A plurality of the fibers may be employed to form a knitted or woven fabric or a nonwoven web. Also provided is a method of preparing fibers containing particles of a ferroelectric material. The method includes destructuring the ferroelectric material in the presence of a liquid and a surfactant to give destructured particles; the liquid is a solvent for the surfactant and the surfactant is adapted to stabilize the destructured particles against agglomeration.

Abstract: A porous polymeric sheet is provided having an electrostatic charge and comprising a zero-three composite of a polymeric matrix and a ferroelectric material dispersed therein. The polymeric component comprises a non-polar thermoplastic polymer, such as a polyolefin, and a second thermoplastic polymer having polar functional units, such as a telomer. The composite material is formed into a porous sheet and is electrically or corona poled to create an electret material which is well suited four use in various filtration, air-masking and dust wipe applications.

Abstract: A porous polymeric sheet is provided having an electrostatic charge and comprising a zero-three composite of a polymeric matrix and a ferroelectric material dispersed therein. The polymeric component comprises a non-polar thermoplastic polymer, such as a polyolefin, and a second thermoplastic polymer having polar functional units, such as a telomer. The composite material is formed into a porous sheet and is electrically or corona poled to create an electret material which is well suited four use in various filtration, air-masking and dust wipe applications.

Abstract: The process of forming an electret nonwoven web, the process including the steps of providing a nonwoven web, generating a DC corona discharge from an apparatus including an anode electrically configured as a parallel device, and subjecting the web to DC corona discharge to form an electret.

Abstract: A fiber which includes a thermoplastic polymer and particles of a ferroelectric material dispersed therein. The thermoplastic polymer may be, for example, a polyolefin, such as polypropylene or polyethylene, and the ferroelectric material may be barium titanate. The ferroelectric material may be present at a level of from about 0.01 to about 50 percent by weight (from about 0.001 to about 13 percent by volume), and will have a longest dimension in a range of from about 10 nanometers to about 10 micrometers. The fiber may be exposed to an electric field. A plurality of the fibers may be employed to form a knitted or woven fabric or a nonwoven web. Also provided is a method of preparing fibers containing particles of a ferroelectric material. The method includes destructuring the ferroelectric material in the presence of a liquid and a surfactant to give destructured particles; the liquid is a solvent for the surfactant and the surfactant is adapted to stabilize the destructured particles against agglomeration.

Abstract: A method for coating the surface of a substrate composed of a hydrophobic polymer with a hydrophobic vinyl polymer. The method includes preparing a solution of the hydrophobic vinyl polymer in a polar nonaqueous solvent, such as 1-methyl-1-pyrrolidinone, in which the hydrophobic vinyl polymer is surface-active. The substrate then is treated with the solution under conditions sufficient to deposit the hydrophobic vinyl polymer on the substrate. The hydrophobic vinyl polymer may have readily hydrolyzable pendant groups which, upon hydrolysis thereof in an aqueous medium, will result in the formation of a hydrophilic vinyl polymer coating on the substrate. For example, the hydrophobic vinyl polymer may be poly(vinyl trifluoroacetate). Also provided are coated substrates, in which the substrate is a shaped article composed of a hydrophobic polymer. The shaped article may be, for example, a film, fiber, or nonwoven web.

Abstract: A method of preparing a dispersion of small particles in a polymeric precursor, which method involves providing a mixture of a particulate material and a surfactant in a nonaqueous solvent, forming a dispersion of the particulate material in the nonaqueous solvent, combining the resulting dispersion of particulate material in the nonaqueous solvent with a precursor material, and heating the combination of the dispersion of particulate material and the precursor material, with mixing, to a temperature sufficient to volatilize the nonaqueous solvent. The surfactant is soluble in the nonaqueous solvent and is adapted to stabilize the particulate material against agglomeration. The nonaqueous solvent swells the polymeric precursor near the boiling point of the nonaqueous solvent. The boiling point of the nonaqueous solvent is greater than a temperature at which the polymeric precursor may be mixed and below a temperature at which the polymeric precursor polymerizes or decomposes.

Abstract: A method for coating the surface of a substrate composed of a hydrophobic polymer with a hydrophobic vinyl polymer. The method includes preparing a solution of the hydrophobic vinyl polymer in a polar nonaqueous solvent, such as 1-methyl-1-pyrrolidinone, in which the hydrophobic vinyl polymer is surface-active. The substrate then is treated with the solution under conditions sufficient to deposit the hydrophobic vinyl polymer on the substrate. The hydrophobic vinyl polymer may have readily hydrolyzable pendant groups which, upon hydrolysis thereof in an aqueous medium, will result in the formation of a hydrophilic vinyl polymer coating on the substrate. For example, the hydrophobic vinyl polymer may be poly(vinyl trifluoroacetate). Also provided are coated substrates, in which the substrate is a shaped article composed of a hydrophobic polymer. The shaped article may be, for example, a film, fiber, or nonwoven web.