The invention provides methods for making porous devices from substantially monodisperse populations of substantially spherical particles of polyarylketone polymers or of thio-analogues of such polymers, of selected sizes. The porous devices allow greater control of porosity than previously available porous devices. In some embodiments, the porous devices are frits, filters, membranes or monoliths.

The invention provides methods for making porous devices from substantially monodisperse populations of substantially spherical particles of polyarylketone polymers or of thio-analogues of such polymers, of selected sizes. The porous devices allow greater control of porosity than previously available porous devices. In some embodiments, the porous devices are frits, filters, membranes or monoliths.

Provided is a polyethylene powder having a density of 910 kg/m.sup.3 or more and less than 935 kg/m.sup.3 and an average particle diameter of 50 μm or more and less than 140 μm, wherein the polyethylene powder contains a particle having a particle diameter of 60 μm and a particle having a particle diameter of 100 μm, the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 2.0 MPa or more and less than 5.0 MPa, and the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 0.5 times or more and less than 1.3 times the compressive strength at 10% displacement of the particle having a particle diameter of 100 μm.

Provided is a polyethylene powder having a density of 910 kg/m.sup.3 or more and less than 935 kg/m.sup.3 and an average particle diameter of 50 μm or more and less than 140 μm, wherein the polyethylene powder contains a particle having a particle diameter of 60 μm and a particle having a particle diameter of 100 μm, the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 2.0 MPa or more and less than 5.0 MPa, and the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 0.5 times or more and less than 1.3 times the compressive strength at 10% displacement of the particle having a particle diameter of 100 μm.

A method of forming cured microparticles includes providing a poly(glycerol sebacate) resin in an uncured state. The method also includes forming the composition into a plurality of uncured microparticles and curing the uncured microparticles to form the plurality of cured microparticles. The uncured microparticles are free of a photo-induced crosslinker. A method of forming a scaffold includes providing microparticles including poly(glycerol sebacate) in a three-dimensional arrangement. The method also includes stimulating the microparticles in the three-dimensional arrangement to sinter the microparticles, thereby forming the scaffold having a plurality of pores. A scaffold is formed of a plurality of microparticles including a poly(glycerol sebacate) thermoset resin in a three-dimensional arrangement. The scaffold has a plurality of pores.

A method of forming cured microparticles includes providing a poly(glycerol sebacate) resin in an uncured state. The method also includes forming the composition into a plurality of uncured microparticles and curing the uncured microparticles to form the plurality of cured microparticles. The uncured microparticles are free of a photo-induced crosslinker. A method of forming a scaffold includes providing microparticles including poly(glycerol sebacate) in a three-dimensional arrangement. The method also includes stimulating the microparticles in the three-dimensional arrangement to sinter the microparticles, thereby forming the scaffold having a plurality of pores. A scaffold is formed of a plurality of microparticles including a poly(glycerol sebacate) thermoset resin in a three-dimensional arrangement. The scaffold has a plurality of pores.

Described are flame retardant, porous plastic flame arrestors. The flame retardant, porous plastic flame arrestor is formed by irradiating a flame retardant polymer resin to achieve a fractional melt index, grinding the flame retardant polymer resin into a powder, and sintering the flame retardant polymer resin to form a porous structure. Irradiating the flame retardant polymer resin increases the resin's molecular weight and reduces the resin's melt index through crosslinking.

Described are flame retardant, porous plastic flame arrestors. The flame retardant, porous plastic flame arrestor is formed by irradiating a flame retardant polymer resin to achieve a fractional melt index, grinding the flame retardant polymer resin into a powder, and sintering the flame retardant polymer resin to form a porous structure. Irradiating the flame retardant polymer resin increases the resin's molecular weight and reduces the resin's melt index through crosslinking.

A method of producing a polyethylene resin expanded molded product includes filling a mold with expanded polyethylene resin particles, wherein an internal pressure of 0.12 to 0.16 MPa is applied to the expanded polyethylene resin particles in the mold, and forming the polyethylene resin expanded molded product by heating the expanded polyethylene resin particles and fusing the expanded polyethylene resin particles. The expanded polyethylene resin particles includes 100 parts by weight of a polyethylene resin, 0.08 to 0.25 parts by weight of a cell nucleating agent, 0.3 to 0.8 parts by weight of a polyhydric alcohol fatty acid ester, and 0.01 to 10 parts by weight of a hydrophilic compound, each of the expanded polyethylene resin particles having a weight of 2.5 to 3.5 mg. The polyethylene resin expanded molded product has a density of 0.017 to 0.021 g/cm.sup.3 and a thickness of 10 to 40 mm.

A method of producing a polyethylene resin expanded molded product includes filling a mold with expanded polyethylene resin particles, wherein an internal pressure of 0.12 to 0.16 MPa is applied to the expanded polyethylene resin particles in the mold, and forming the polyethylene resin expanded molded product by heating the expanded polyethylene resin particles and fusing the expanded polyethylene resin particles. The expanded polyethylene resin particles includes 100 parts by weight of a polyethylene resin, 0.08 to 0.25 parts by weight of a cell nucleating agent, 0.3 to 0.8 parts by weight of a polyhydric alcohol fatty acid ester, and 0.01 to 10 parts by weight of a hydrophilic compound, each of the expanded polyethylene resin particles having a weight of 2.5 to 3.5 mg. The polyethylene resin expanded molded product has a density of 0.017 to 0.021 g/cm.sup.3 and a thickness of 10 to 40 mm.