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.

A thermoplastic poly(urethane-urea) polyadduct (I) with sterically hindered urea groups used in an electrospinning method for producing vascular prostheses:

##STR00001## I, M, C.sub.1 and C.sub.2 represent bivalent radicals linked via a urethane or urea moiety; I and C.sub.2 represent a bivalent, saturated or unsaturated, aliphatic, alicyclic or aromatic radical with 1-20 carbon atoms derived from (I): a diisocyanate; or (C.sub.2): from a diol, diamine or amino alcohol; M represents a bivalent radical of an aliphatic polyether, polyester or polycarbonate derived from a macrodiol having M.sub.n?500; C.sub.1 represents a bivalent, saturated or unsaturated, aliphatic or alicyclic radical with 1-30 carbon atoms derived from a diamine or amino alcohol with ?1 sterically hindered secondary amino group through removal of one N-linked hydrogen atom of the diamine or one N-linked and the O-linked hydrogen atoms of the amino alcohol.

A thermoplastic poly(urethane-urea) polyadduct (I) with sterically hindered urea groups used in an electrospinning method for producing vascular prostheses:

##STR00001## I, M, C.sub.1 and C.sub.2 represent bivalent radicals linked via a urethane or urea moiety; I and C.sub.2 represent a bivalent, saturated or unsaturated, aliphatic, alicyclic or aromatic radical with 1-20 carbon atoms derived from (I): a diisocyanate; or (C.sub.2): from a diol, diamine or amino alcohol; M represents a bivalent radical of an aliphatic polyether, polyester or polycarbonate derived from a macrodiol having M.sub.n?500; C.sub.1 represents a bivalent, saturated or unsaturated, aliphatic or alicyclic radical with 1-30 carbon atoms derived from a diamine or amino alcohol with ?1 sterically hindered secondary amino group through removal of one N-linked hydrogen atom of the diamine or one N-linked and the O-linked hydrogen atoms of the amino alcohol.

The present invention is directed to a reactive dye-dyeable polyurethane-urea elastic yarn including a reaction product of at least two polyols, a diisocyanate compound, a diamine chain extender, an amine chain terminator, and a diethylenetriamine compound, wherein one of the polyols is polyethylene glycol, which is included in an amount of 20 to 30.0 mol % based on the total amount of the polyols, a polyurethane-urea polymer includes 10 meq/kg to 45 meq/kg of primary amine ends, and the capping ratio (CR) of the diisocyanate to the polyols is 1.8 to 2.0.

The present invention is directed to a reactive dye-dyeable polyurethane-urea elastic yarn including a reaction product of at least two polyols, a diisocyanate compound, a diamine chain extender, an amine chain terminator, and a diethylenetriamine compound, wherein one of the polyols is polyethylene glycol, which is included in an amount of 20 to 30.0 mol % based on the total amount of the polyols, a polyurethane-urea polymer includes 10 meq/kg to 45 meq/kg of primary amine ends, and the capping ratio (CR) of the diisocyanate to the polyols is 1.8 to 2.0.

The present invention relates to a fiber for artificial hair having a hollow in a center of a fiber cross section. A ratio of an area of the hollow to an entire area of the fiber cross section is 5% to 50%. The fiber cross section has a flat multilobed shape, and the hollow has a first side and a second side that are inclined 70 to 110 degrees relative to a major axis of the fiber cross section. The present invention also relates to hair ornament products including the above fiber for artificial hair. Thus, the present invention provides a fiber for artificial hair having a favorable curl setting property when curling with a hair iron and a favorable combing property after curling with a hair iron, and hair ornament products including the same.

The present invention relates to a fiber for artificial hair having a hollow in a center of a fiber cross section. A ratio of an area of the hollow to an entire area of the fiber cross section is 5% to 50%. The fiber cross section has a flat multilobed shape, and the hollow has a first side and a second side that are inclined 70 to 110 degrees relative to a major axis of the fiber cross section. The present invention also relates to hair ornament products including the above fiber for artificial hair. Thus, the present invention provides a fiber for artificial hair having a favorable curl setting property when curling with a hair iron and a favorable combing property after curling with a hair iron, and hair ornament products including the same.

This application provides a polyimide fiber and a preparation method thereof. This method comprises first subjecting a dianhydride compound and a diamine compound to a polymerization reaction in a solvent to obtain a polyamic acid solution, wherein said diamine compound comprises a diamine having a structure of Formula 12 or Formula 13, wherein A is S or O; said dianhydride compound comprises one or more of dianhydrides having structures of Formula 14 and Formula 15; and t is 0 or 1; then subjecting said polyamic acid solution to spinning to obtain a polyamic acid fiber; and sequentially subjecting said polyamic acid fiber to imidization and thermal drawing to obtain a polyimide fiber. The polyimide fiber having the above structure has a higher rigidity and can introduce a hydrogen bond to provide an interaction between molecular chains so as to influence the arrangement of the molecular chain in the polymer and the crystallinity, which imparts more excellent mechanical properties to the polyimide fiber. The polyimide fiber obtained has a higher glass transition temperature (Tg) and a better heat resistance.

##STR00001##

The present invention relates to a fiber for artificial hair having a hollow in a center of a fiber cross section. A ratio of an area of the hollow to an entire area of the fiber cross section is 5% to 50%. The fiber cross section has a flat multilobed shape, and the hollow has a first side and a second side that are inclined 70 to 110 degrees relative to a major axis of the fiber cross section. The present invention also relates to hair ornament products including the above fiber for artificial hair. Thus, the present invention provides a fiber for artificial hair having a favorable curl setting property when curling with a hair iron and a favorable combing property after curling with a hair iron, and hair ornament products including the same.

The present invention relates to a fiber for artificial hair having a hollow in a center of a fiber cross section. A ratio of an area of the hollow to an entire area of the fiber cross section is 5% to 50%. The fiber cross section has a flat multilobed shape, and the hollow has a first side and a second side that are inclined 70 to 110 degrees relative to a major axis of the fiber cross section. The present invention also relates to hair ornament products including the above fiber for artificial hair. Thus, the present invention provides a fiber for artificial hair having a favorable curl setting property when curling with a hair iron and a favorable combing property after curling with a hair iron, and hair ornament products including the same.