A method of preparing polymer particles includes combining a polyetherimide and a solvent at a first temperature to provide a slurry, wherein the polyetherimide is not soluble in the solvent at the first temperature; heating the slurry to a second temperature and at a pressure effective to dissolve the polyetherimide in the solvent to provide a homogenous solution; cooling the homogenous solution to a third temperature to provide a dispersion including a plurality of polymer particles; and isolating the polymer particles. The polymer particles have a Dv90 particle size of less than or equal to 250 micrometers. Polymers powders prepared according to the method are also described herein, wherein the powder includes a plurality of semi-crystalline polymer particles having a Dv90 of less than or equal to 250 micrometers.

A polymer dispersion is disclosed. The polymer dispersion includes a liquid crystal polymer powder, a polyamide acid, and a solvent. A solid content of the polymer dispersion includes the liquid crystal polymer powder and the polyamide acid. The liquid crystal polymer powder has a mass ratio of 20% to 30% in the solid content. The polyamide acid has a mass ratio of 70% to 80% in the solid content. The polyamide acid is obtained by mixing two kinds of diamines and two kinds of dianhydrides together, causing the diamines and the dianhydrides to be polymerized with each other. Both two kinds of diamines and two kinds of dianhydrides comprise a liquid crystal structure and a flexible structure respectively. A method of preparing the polymer dispersion, and a method for preparing a polymer composite film using the polymer dispersion are also disclosed.

A polymer dispersion is disclosed. The polymer dispersion includes a liquid crystal polymer powder, a polyamide acid, and a solvent. A solid content of the polymer dispersion includes the liquid crystal polymer powder and the polyamide acid. The liquid crystal polymer powder has a mass ratio of 20% to 30% in the solid content. The polyamide acid has a mass ratio of 70% to 80% in the solid content. The polyamide acid is obtained by mixing two kinds of diamines and two kinds of dianhydrides together, causing the diamines and the dianhydrides to be polymerized with each other. Both two kinds of diamines and two kinds of dianhydrides comprise a liquid crystal structure and a flexible structure respectively. A method of preparing the polymer dispersion, and a method for preparing a polymer composite film using the polymer dispersion are also disclosed.

A method for preparing a stabilized assembly includes combining a first liquid phase including nanoparticles and a second, immiscible liquid phase, dissolving in the second phase a first end-functionalized polymer having a first molecular weight, and a second end-functionalized polymer having a second molecular weight, wherein the second molecular weight is greater than the first molecular weight, applying a shearing external deformation field to increase the surface area of the first phase to create a new interface, wherein the nanoparticle surfactants form a disordered, jammed assembly at the new interface, and releasing the shearing external deformation field. The polymer and the nanoparticles can interact at an interface through ligand interactions to form nanoparticle surfactants and upon releasing the external deformation field the jammed assembly at the new interface traps the first phase in a deformed state having the first liquid phase and the second liquid phase as interpenetrating domains.

A method for preparing a stabilized assembly includes combining a first liquid phase including nanoparticles and a second, immiscible liquid phase, dissolving in the second phase a first end-functionalized polymer having a first molecular weight, and a second end-functionalized polymer having a second molecular weight, wherein the second molecular weight is greater than the first molecular weight, applying a shearing external deformation field to increase the surface area of the first phase to create a new interface, wherein the nanoparticle surfactants form a disordered, jammed assembly at the new interface, and releasing the shearing external deformation field. The polymer and the nanoparticles can interact at an interface through ligand interactions to form nanoparticle surfactants and upon releasing the external deformation field the jammed assembly at the new interface traps the first phase in a deformed state having the first liquid phase and the second liquid phase as interpenetrating domains.

Ways of preparing a partially crystalline polycarbonate powder are provided that include dissolving an amorphous polycarbonate in a polar aprotic solvent to form a first solution of solubilized polycarbonate at a first temperature. The first solution is then cooled to a second temperature, the second temperature being lower than the first temperature, where a portion of the solubilized polycarbonate precipitates from the first solution to form a second solution including the partially crystalline polycarbonate powder. Certain partially crystalline polycarbonate powders resulting from such methods are particularly useful in additive manufacturing processes, including powder bed fusion processes.

A method for manufacturing resin particles is provided. The method includes the steps of: dissolving a resin free of poly(lactic-co-glycolic acid) (PLGA) in a good solvent of the resin to prepare a resin solution; and discharging the resin solution from at least one discharge hole having an inner diameter of less than 1,000 μm into a poor solvent of the resin to form resin particles.

A method for manufacturing resin particles is provided. The method includes the steps of: dissolving a resin free of poly(lactic-co-glycolic acid) (PLGA) in a good solvent of the resin to prepare a resin solution; and discharging the resin solution from at least one discharge hole having an inner diameter of less than 1,000 μm into a poor solvent of the resin to form resin particles.

An optimized process for the preparation of a spinning solution for the production of acrylic fiber precursors (PAN) of carbon fibers and an optimized process for the production of carbon fibers from said acrylic precursor (PAN), are described.

The present invention aims to provide a paste containing polytetrafluoroethylene which can be formed into a molded polytetrafluoroethylene article having a significantly small thickness of polytetrafluoroethylene and is less likely to cause defects in molding; and a method of producing the paste. The present invention provides a method of producing a paste, including the steps of coagulating primary particles of polytetrafluoroethylene in an aqueous dispersion that contains the primary particles and water to form slurry that contains secondary particles of polytetrafluoroethylene and water or secondary particles of polytetrafluoroethylene floating in water; and adding an organic solvent to at least one of the slurry and the secondary particles of polytetrafluoroethylene floating in water to provide the paste.