Abstract: A cellulose fiber can reduce environmental burden while providing an enhanced modulus of elasticity easily and reliably. A composite material contains the cellulose fiber. A method of producing the cellulose fiber includes preparing a solution where needle-shaped phases each comprising a cellulose I crystal structure are dispersed in a matrix phase comprising a cellulose II crystal structure. The cellulose fiber includes the matrix phase and the needle-shaped phases contained in the matrix phase and the needle-shaped phases are oriented along an axial direction.

Abstract: A cellulose fiber can reduce environmental burden while providing an enhanced modulus of elasticity easily and reliably. A composite material contains the cellulose fiber. A method of producing the cellulose fiber includes preparing a solution where needle-shaped phases each comprising a cellulose I crystal structure are dispersed in a matrix phase comprising a cellulose II crystal structure. The cellulose fiber includes the matrix phase and the needle-shaped phases contained in the matrix phase and the needle-shaped phases are oriented along an axial direction.

Abstract: According to the present invention, a urethane foam rubber is constituted with a polymer having a moiety derived from a diisocyanate, and a moiety derived from a polyether polyol, number of atoms composing the shortest path along a bond intervening two NCO groups in at least a part of the diisocyanate is no less than 11, Mw of the polyether polyol is no less than 1,000 and no greater than 4,000, and the polymer exhibits at least one of the following features (i) to (iii): (i) having moieties derived from two or more types of the polyether polyols that are each different in terms of at least one of a weight average molecular weight and an oxyalkylene unit; (ii) having the moiety derived from the polyether polyol that includes two or more types of oxyalkylene units; and (iii) further having a moiety derived from a tri- or higher multi-functional isocyanate.