Abstract:
A nonwoven web and method of preparing a novel nonwoven web of superabsorbent fiber are disclosed. An aqueous solution of superabsorbent precursor polymer is extruded under defined conditions through a plurality of die orifices to form a plurality of threadlines. The threadlines are attenuated with a defined primary gaseous source to form fiber under conditions of controlled macro scale turbulence and under conditions sufficient to permit the viscosity of each threadline, as it leaves a die orifice and for a distance of no more than about 8 cm, to increase incrementally with increasing distance from the die, while substantially maintaining uniformity of viscosity in the radial direction, at a rate sufficient to provide fiber having the desired attenuation and mean fiber diameter without significant fiber breakage. The attenuated threadlines are dried with a defined secondary gaseous source. The resulting fibers are deposited randomly on a moving foraminous surface to form a substantially uniform web. Moving foraminous surface is positioned about 10 to about 100 cm from the last gaseous source to contact the threadlines. The fibers have a mean fiber diameter in the range of about 0.1 to 30 mu m and are substantially free of shot. The attenuating and drying steps are carried out under conditions of controlled macro scale turbulence.
Abstract:
Fibre or film of water-absorbent water-insoluble fibrous material has a matrix of a cross-linked copolymer formed from 50 to 95 % by weight of ethylenically unsaturated carboxylic monomer and 5 to 50 % by weight of copolymerisable ethylenically unsaturated monomer. The matrix contains regions of a dispersed polymeric material, the matrix copolymer and the dispersed polymeric material being mutually immiscible and chemically substantially non-reactive under ambient conditions. The fibre or film can be produced by extruding a solution or dispersion of the polymeric material in a solution of the matrix copolymer in its non-cross-linked state into a gaseous environment.
Abstract:
The present invention proposes an electrospinning composition comprising a catalyst and a functionalized polymer or copolymer bearing one or more epoxy ring, said mixture further comprises an anhydride, preferably phthalic anhydride as a cross-linking agent; wherein the epoxy:anhydride molar ratio in the electrospinning composition is within the range between 1:1 and 50:1. The present invention further proposes a method for preparation of such electrospinning composition, electrospun nano-/submicrostructures prepared using said method and composite material comprising such electrospun nano-/submicrostructures.
Abstract:
A fibrous properties-switching article comprises a mat consisting of fibers having a fiber diameter of 2 microns or less. The fibers comprise a polymer, copolymer, polymer blend, or polymer network, wherein the fibers have a diameter of 2 μιη or less. The surface and/or bulk property of the mat changes over a range of temperatures, wherein the polymer, copolymer, polymer blend, or polymer network undergoes a structural change over the range of temperatures. The fiber mat is formed by electrospinning. In an exemplary embodiment, a blend of polystyrene and poly((N-isopropyl acrylamide) (bl-PS/PNIPA) in dimethylformamide (DMF) is electrospun to form a mat consisting of fibers with a diameter less than 2 μηι that shows a transition from a superhydrophilic surface to a nearly superhydrophobic surface over a temperature range from 30 °C to 45 °C. A fiber mat formed by electrospinning a DMF solution comprising poly(N-isopropyl acrylamide-co- methacylicacid) (PNIPAMAA), comprises fibers having a diameter less than 2 μιτι and are cross linked after spinning. The crosslinked PNIPAMAA, (xl-PNIPAMAA) fiber mat displays a transition from a hydrophilic surface to a nearly hydrophobic surface over a temperature range from 30 °C to 45 °C.
Abstract:
Die vorliegende Erfindung betrifft wasserabsorbierende Polymergebilde, beinhaltend, bezogen auf das Gesamtgewicht der wasserabsorbierenden Polymergebilde, 0,001 bis 10 Gew.-% eines Farbmittels, wobei das wasserabsorbierende Polymergebilde durch einen gemäß der hierin beschriebenen Testmethode bestimmten L-Wert gemäß dem L,a,b-Farbsystem kleiner als 90 gekennzeichnet ist bzw. wobei der Farbstoff homogen im Inneren des wasserabsorbierenden Polymergebildes verteilt ist. Die Erfindung betrifft auch ein Verfahren zur Herstellung wasserabsorbierender Polymergebilde, die durch dieses Verfahren erhältlichen wasserabsorbierenden Polymergebilde, einen Verbund beinhaltend wasserabsorbierende Polymergebilde und ein Substrat, ein Verfahren zur Herstellung eines Verbundes, einen durch dieses Verfahren erhältlichen Verbund, chemische Produkte beinhaltend wasserabsorbierende Polymergebilde oder einen Verbund sowie die Verwendung wasserabsorbierender Polymergebilde oder eines Verbund in chemischen Produkten.
Abstract:
Apparatus and methods for fabricating nanofibers by reactive electrospinning are described. An electrospinning process is coupled with an in-line reactor where chemical or photochemical reactions take place. This invention expands the application of the electrospinning and allows the production of nanofibers of crosslinked polymers and other new materials, such as gel nanofibers of ceramic precursors.
Abstract:
A supramolecular polymer with living characteristics is provided based on small molecules or metal complexes of a planar or linear geometry and a polymer. The small molecules are solvophobic and can associate or assemble with each other through non-covalent interactions such as but not limited to metal–metal, π–π, hydrogen-bonding, and/or solvophobic–solvophobic interactions, in the modulation of the polymer. The polymer has affinity to the medium (e.g., solvent) and still interacts with the small molecules via non-covalent interactions such as electrostatic attractions to stabilize the associated/assembled small molecules. Varying the composition and/or length of the polymer can modulate the dimensions of the supramolecular polymer and the nanostructures therefrom. The two-or multi-component supramolecular polymer has active ends to support further supramolecular polymerization upon addition of small molecules of a planar or linear geometry. A process of two-component living supramolecular polymerization is also provided.