The invention relates to a preparation method of a
fiber with high water absorption, which is a method for preparing the
fiber with high water absorption by a post-crosslinking agent. According to the preparation method, the
fiber with high water absorption is prepared from
acrylic acid (AA) and
acrylamide (AM) which are partly neutralized and taken as polymerized monomers through the steps of: blending the polymerized monomers with polyving akohol (PVA), initiating by
potassium persulfate (KPS), blending and polymerizing in an
aqueous solution, adding a dialdehyde solution to obtain a
mixed solution serving as a post-crosslinking agent solution, mixing to be uniform and defoaming to obtain a
spinning stock solution; dry-wet
spinning the
spinning stock solution to form a nascent fiber; and heat-treating the nascent fiber at a certain temperature to generate a crosslinking reaction, thereby forming the three-dimensional net-structured fiber with high water absorption. According to the preparation method, the implosion phenomenon which easily occurs during
polymerization of the traditional
polymer solution with high water absorption is avoided, the preparation technology is simple and safe, the production cost is reduced, and the production efficiency is increased; and the obtained water-absorbing fiber has high and controllable water adsorption,
thermostability, capability of being repeatedly used, and long residual action.