Described are dissolvable, porous solid structures formed using certain vinyl acetate-vinyl alcohol copolymers. The copolymer and the porosity of the structure allow for liquid flow during use such that the structure readily dissolves to provide a desired consumer experience. Also described are processes for making open cell foam and fibrous dissolvable solid structures.

Provided is a hollow fiber membrane that is excellent in water vapor separation performance immediately after production and water vapor separation performance after repeated use with compressed air. A hollow fiber membrane comprising a polyarylate resin, wherein the hollow fiber membrane includes a skin layer on at least one of inner and outer surfaces, has a tensile strength of 7 MPa or more and an elongation at break of 15% or more, and has an internal pressure water permeability of less than 100 L/(m.sup.2.Math.atm/h) as measured using pure water at 25° C.

Provided is a hollow fiber membrane that is excellent in water vapor separation performance immediately after production and water vapor separation performance after repeated use with compressed air. A hollow fiber membrane comprising a polyarylate resin, wherein the hollow fiber membrane includes a skin layer on at least one of inner and outer surfaces, has a tensile strength of 7 MPa or more and an elongation at break of 15% or more, and has an internal pressure water permeability of less than 100 L/(m.sup.2.Math.atm/h) as measured using pure water at 25° C.

Disclosed is a fiber for artificial hair containing a polycondensation-based polymer and a crosslinking agent. Also disclosed is a headdress article including the fiber for artificial hair.

Disclosed is a fiber for artificial hair containing a polycondensation-based polymer and a crosslinking agent. Also disclosed is a headdress article including the fiber for artificial hair.

A yarn may include at least one filament formed from a polymer composition comprising: a polymer at an amount ranging from 95 wt % to 99.99 wt %; a carbon-based nanomaterial at an amount ranging from 0.01 wt % to 5 wt %. A method may include melt spinning a polymer composition to produce a yarn, where the polymer composition includes a polymer at an amount ranging from 95 wt % to 99.99 wt %; a carbon-based nanomaterial at an amount ranging from 0.01 wt % to 5 wt %.

A chitin-modified polypropylene spunbond non-woven fabric and a preparation method of the chitin-modified polypropylene spunbond non-woven fabric are provided. The chitin-modified polypropylene spunbond non-woven fabric contains a modified chitin in a weight percentage range of approximately 0.2%-1.5%. The modified chitin includes chitin modified by a modifier including 2-hydroxybenzimidazole, cellulose acetate butyrate, and adipic acid dihydrazide. The chitin-modified polypropylene spunbond non-woven fabric has an anti-mold grade less than 1, and an antibacterial rate greater than 9.5%.

In a first embodiment, a coal treatment process includes exposing a material comprising coal to ionic liquid(s) to form a first mixture, isolating a residue from the first mixture, forming a second mixture comprising the residue, and electrospinning the second mixture to form a carbon fiber precursor material. In a second embodiment, a coal treatment process includes exposing a material comprising coal to ionic liquid(s) to form a mixture comprising solids and a liquid fraction, separating and filtering the liquid fraction from the mixture, and isolating one or more compounds from the liquid fraction. In a third embodiment, a coal treatment process includes exposing a material comprising coal to ionic liquid(s) to form a first mixture comprising residues, exposing the first mixture to (a) an acid, (b) a solvent, or (c) both to form a second mixture, and isolating rare earth elements and rare earth element compounds.

In a first embodiment, a coal treatment process includes exposing a material comprising coal to ionic liquid(s) to form a first mixture, isolating a residue from the first mixture, forming a second mixture comprising the residue, and electrospinning the second mixture to form a carbon fiber precursor material. In a second embodiment, a coal treatment process includes exposing a material comprising coal to ionic liquid(s) to form a mixture comprising solids and a liquid fraction, separating and filtering the liquid fraction from the mixture, and isolating one or more compounds from the liquid fraction. In a third embodiment, a coal treatment process includes exposing a material comprising coal to ionic liquid(s) to form a first mixture comprising residues, exposing the first mixture to (a) an acid, (b) a solvent, or (c) both to form a second mixture, and isolating rare earth elements and rare earth element compounds.

A method for producing a polyurethane elastic fiber according to the present invention contains the steps of: [1] producing a polyurethane urea polymer (A) having a number average molecular weight ranging from 12,000 to 50,000, and represented by general formula (1); [2] preparing a spinning dope by adding the polyurethane urea polymer (A) to a polyurethane urea polymer (B); and [3] spinning a polyurethane elastic fiber using the spinning dope.

##STR00001##

In the formula, R.sup.1 and R.sup.2 are an alkyl group or a hydroxyalkyl group, R.sup.3 is an alkylene group, a polyethyleneoxy group or a polypropyleneoxy group, R.sup.4 is a diisocyanate residue, X is a urethane bond or a urea bond, R.sup.5 and R.sup.6 are a diisocyanate residue, P is a diol residue, Q is a diamine residue, UT is a urethane bond, UA is a urea bond, each of k, 1, m and n is 0 or a positive number.