The present invention relates to a fibrous 3-dimensional porous scaffold obtained by electro-spinning for tissue regeneration and a method for preparing the same.

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, l, m and n is 0 or a positive number.

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, l, m and n is 0 or a positive number.

A method of forming a polymer-metal nanocomposite (PMNC) material with a substantially uniform dispersion of metal particles includes forming a composite solid preform by mixing a blend of micrometer-sized metal particles and polymer particles and subjecting the mixture to compression followed by sintering. The composite solid preform is drawn through a heated zone to form a reduced size fiber. The reduced size fiber is cut into segments and a next preform is formed using the bundle of the segments. The next preform is then drawn through the heated zone to form yet another reduced size fiber. This reduced size fiber may undergo one or more stack-and-draw operations to yield a final fiber having substantially uniform dispersion of nanometer-sized metal particles therein.

A copolymer fiber is prepared from a composition that includes specific amounts of a block polyestercarbonate-polysiloxane and a flame retardant. The fiber has an equivalent circular diameter of 10 to 60 micrometers. Also described are a method of forming the fiber, and various articles incorporating the fiber, including woven fabrics, knit fabrics, and nonwoven fabrics.

A biodegradable cardiovascular implant is provided for growing cardiovascular tissue in a patient. The implant distinguishes an electro-spun network with supramolecular compounds having hard-blocks covalently bonded with soft-blocks resulting in much enhanced durability and fatigue resistance, while maintaining the effectiveness as a cardiovascular implant.

[Problem] To provide: a carbon fiber precursor fiber that can efficiently produce a carbon fiber at a low cost which is excellent in mechanical strengths even without an infusibilization treatment; a carbon fiber; and a method for producing the carbon fiber.

[Solution] A carbon fiber precursor fiber of the present invention includes a polymer containing a constituent unit represented by General Formula (1) below:

##STR00001## where in the General Formula (1), X and Y each independently represent a divalent substituent, a single bond, or a structure forming a fused ring by sharing one side of two adjacent rings, and the divalent substituent is selected from the group consisting of O, S, OSO, NH, CO, CH.sub.2, and CH(CH.sub.3).sub.2.

[Problem] To provide: a carbon fiber precursor fiber that can efficiently produce a carbon fiber at a low cost which is excellent in mechanical strengths even without an infusibilization treatment; a carbon fiber; and a method for producing the carbon fiber.

[Solution] A carbon fiber precursor fiber of the present invention includes a polymer containing a constituent unit represented by General Formula (1) below:

##STR00001## where in the General Formula (1), X and Y each independently represent a divalent substituent, a single bond, or a structure forming a fused ring by sharing one side of two adjacent rings, and the divalent substituent is selected from the group consisting of O, S, OSO, NH, CO, CH.sub.2, and CH(CH.sub.3).sub.2.

A method for producing a polyacetal fiber that presents an improved whiteness unevenness is provided. According to one embodiment, there is provided a polyacetal fiber production method that yields a polyacetal fiber using an oxymethylene copolymer having a melt index, at 190 C. under a load of 2.16 kg, of 5-60 g/10 min, wherein the production method includes taking off the polyacetal fiber from the discharge nozzle of a spinning apparatus, and drawing the taken-off polyacetal fiber. The tensile elongation E1 of the polyacetal fiber after the taking off is 20%-500%; the tensile elongation E2 of the polyacetal fiber after the drawing is 10%-100%; E1E2; and the single fiber thickness of the polyacetal fiber after the drawing is 0.7-5.0 denier.

A filament for use in forming a support structure in fused filament fabrication includes an amorphous, thermoplastic resin having a glass transition temperature from 165 C. to 350 C., and 0.5 to 4.5 weight percent of a high viscosity silicone having a kinematic viscosity from 60,000 to 100 million centistokes. The composition used to form the support filament exhibits a desirable combination of filament formability, printability in additive manufacturing, lack of significant oozing from the printer nozzle, and ease of mechanical separation from the build material at room temperature after printing.