Abstract: Useful thermoplastic polymer powders are formed by a method comprising: cooling a foam comprised of a thermoplastic foam below the brittleness temperature of the thermoplastic polymer, wherein the foam has an average strut dimension of 10 to 500 micrometers, and comminuting the cooled foam to form a thermoplastic polymer powder. The method allows for the efficient grinding of the thermoplastic polymer having improved morphology and desirable characteristics such as dry flow without flow aids.

Abstract: Useful thermoplastic polymer powders are formed by a method comprising: cooling a foam comprised of a thermoplastic foam below the brittleness temperature of the thermoplastic polymer, wherein the foam has an average strut dimension of 10 to 500 micrometers, and comminuting the cooled foam to form a thermoplastic polymer powder. The method allows for the efficient grinding of the thermoplastic polymer having improved morphology and desirable characteristics such as dry flow without flow aids.

Abstract: A semicrystalline polyketone powder useful for additive manufacturing may be made by dissolving a polyketone having differential scanning calorimetry (DSC) monomodal melt peak, at a temperature above 50° C. to below the melt temperature of the polyketone, precipitating the dissolved polyketone by cooling, addition of a nonsolvent or combination thereof. The method may be used to form polyketones having a DSC melt peak with an enthalpy greater than the starting polyketone.

Abstract: A semicrystalline polyarylethersulfone (PAES) useful for additive manufacturing may be made by a method comprising: dissolving an amorphous polyarylethersulfone in a polar aprotic halogenated hydrocarbon solvent at a temperature adequate to effectively form a solution, and subsequently and spontaneously bring about reprecipitation of a semicrystalline polyarylethersulfone from the solution. The semicrystalline polyarylethersulfone may have a crystallinity of at least 30% by weight. The semicrystalline PAES, upon being heated, melting and uniting together in layers during additive manufacturing cools without substantially recrystallizing, allows for deformation-free articles to be formed having low residual stress.