Polyphenylene sulfide microparticles have a linseed oil absorption amount of 40 to 1,000 mL/100 g and a number average particle diameter of 1 to 200 μm. The porous PPS microparticles have a large specific surface area and therefore promote fusion of particles when molded into various molded bodies by applying thermal energy, thus enabling formation or molding of a coating layer of particles at a lower temperature in a shorter time. The porous PPS microparticles have a porous shape and therefore enable scattering light in multiple directions and suppression of specific reflection of reflected light in a specific direction, thus making it possible to impart shading effect and matte effect when added to a medium.

A polyolefin microporous membrane is disclosed. The membrane has a width of not less than 100 mm, and a variation range of an F25 value in a width direction is not greater than 1 MPa. The F25 value is a value obtained by dividing a load at 25% elongation of a sample of the laminated polyolefin microporous membrane as measured with a tensile testing machine by a cross-sectional area of the sample.

Porous three-dimensional networks of polyimide and porous three-dimensional networks of carbon and methods of their manufacture are described. For example, polyimide aerogels are prepared by mixing a dianhydride and a diisocyanate in a solvent comprising a pyrrolidone and acetonitrile at room temperature to form a sol-gel material and supercritically drying the sol-gel material to form the polyimide aerogel. Porous three-dimensional polyimide networks, such as polyimide aerogels, may also exhibit a fibrous morphology. Having a porous three-dimensional polyimide network undergo an additional step of pyrolysis may result in the three dimensional network being converted to a purely carbon skeleton, yielding a porous three-dimensional carbon network. The carbon network, having been derived from a fibrous polyimide network, may also exhibit a fibrous morphology.

Porous three-dimensional networks of polyimide and porous three-dimensional networks of carbon and methods of their manufacture are described. For example, polyimide aerogels are prepared by mixing a dianhydride and a diisocyanate in a solvent comprising a pyrrolidone and acetonitrile at room temperature to form a sol-gel material and supercritically drying the sol-gel material to form the polyimide aerogel. Porous three-dimensional polyimide networks, such as polyimide aerogels, may also exhibit a fibrous morphology. Having a porous three-dimensional polyimide network undergo an additional step of pyrolysis may result in the three dimensional network being converted to a purely carbon skeleton, yielding a porous three-dimensional carbon network. The carbon network, having been derived from a fibrous polyimide network, may also exhibit a fibrous morphology.

This polyolefin microporous membrane has a TD thermal shrinkage at 120° C. of 8% or less, and the TD thermal shrinkage at 130° C. thereof is 3 to 5 times greater than the TD thermal shrinkage at 120° C. and at least 12% greater than the TD thermal shrinkage at 120° C.

This polyolefin microporous membrane has a TD thermal shrinkage at 120° C. of 8% or less, and the TD thermal shrinkage at 130° C. thereof is 3 to 5 times greater than the TD thermal shrinkage at 120° C. and at least 12% greater than the TD thermal shrinkage at 120° C.

The present invention relates to methods of forming aerogels.

The present invention relates to methods of forming aerogels.

A process for forming voided latex particles is improved by combining swelling and polymerization of an outer shell into a single step. The process includes contacting multi-stage emulsion polymer particles comprising a core, at least one intermediate shell, with a swelling agent, and polymerizing an outer shell after said contacting with swelling agent wherein the core and the at least one intermediate shell are contacted with swelling agent in the presence of less than 0.5% monomer based on the weight of the multi-stage emulsion polymer particles, and substantially all of the swelling occurs during polymerization of the outer shell.

A process for forming voided latex particles is improved by combining swelling and polymerization of an outer shell into a single step. The process includes contacting multi-stage emulsion polymer particles comprising a core, at least one intermediate shell, with a swelling agent, and polymerizing an outer shell after said contacting with swelling agent wherein the core and the at least one intermediate shell are contacted with swelling agent in the presence of less than 0.5% monomer based on the weight of the multi-stage emulsion polymer particles, and substantially all of the swelling occurs during polymerization of the outer shell.