摘要:
Disclosed are processes for manufacturing cross-linked cellulosic fibers and tissue products comprising cross-linked cellulosic fibers, manufactured by reacting an oxidized polyol, in particular, an oxidized sugar having at least two aldehyde groups with a plurality of cellulosic fibers to yield treated fibers and heating the treated fibers at a temperature greater than about 140° C. to cure the treated fibers. In particular, said sugar is sucrose and the oxidising agent comprises hydrogen peroxide. The instant cross-linked fibers are manufactured without well-known cross-linking agents such as formaldehyde or polycarboxylic acids, and have good brightness and color and resist yellowing. Furthermore, the cross-linked cellulosic fibers are generally free from off odors and the instant cross-linked cellulosic fibers have enhanced properties, such as improved wet bulk, compared to uncross-linked fibers.
摘要:
Pulps in accordance with certain embodiments include crosslinked cellulose fibers and have high brightness, reactivity, and intrinsic viscosity, and therefore can be well suited for use as a precursor in the production of low-color, high-viscosity cellulose derivatives. A method in accordance with the present technology includes forming a pulp from a cellulosic feedstock, bleaching the pulp, crosslinking cellulose fibers within the pulp while the pulp has a high consistency, and drying the pulp. Crosslinking the cellulose fibers can include exposing the fibers to a glycidyl ether crosslinker having two or more glycidyl groups and a molecular weight per epoxide within a range from 140 to 175. Another method in accordance with the present technology includes providing an aqueous suspension of pulp that includes chemical wood pulp fibers that were previously bleached and dried, crosslinking the fibers with such a glycidal ether crosslinker, and drying the pulp.
摘要:
A pulp in accordance with a particular embodiment includes crosslinked cellulose fibers. The pulp can have high brightness, reactivity, and intrinsic viscosity. The pulp, therefore, can be well suited for use as a precursor in the production of low-color, high-viscosity cellulose derivatives. A method in accordance with a particular embodiment of the present technology includes forming a pulp from a cellulosic feedstock, bleaching the pulp, crosslinking cellulose fibers within the pulp while the pulp has a high consistency, and drying the pulp. The bleaching process can reduce a lignin content of the pulp to less than or equal to 0.09% by oven-dried weight of the crosslinked cellulose fibers. Crosslinking the cellulose fibers can include exposing the cellulose fibers to a glycidyl ether crosslinker having two or more glycidyl groups and a molecular weight per epoxide within a range from 140 to 175.
摘要:
There is proposed a separation method for mixtures of materials, using a cellulose hydrate membrane having a porous double structure which consists of micropores having a diameter in the range from >100 nm to 20 μm and ultrapores which have a diameter of
摘要:
A hydrogel is provided which is obtained by reacting an azide group and a cyclooctyne group in the absence of a catalyst, especially in the absence of a copper catalyst. The hydrogel has: (a) a first polymer moiety composed of hyaluronic acid, carboxymethyl dextran or the like; (b) a second polymer moiety composed of hyaluronic acid, carboxymethyl dextran or the like, said second polymer moiety being of a kind that is same as or different from the kind of the moiety (a) and is composed of a molecule different from the moiety (a); and (c) a triazole ring group or a derivative group thereof.
摘要:
This invention involves a composition, a method of making, and an application of high plasticization-resistant chemically cross-linked polymeric membranes such as cross-linked cellulose acetate (CA) membrane. These cross-linked polymeric membranes with covalently interpolymer-chain-connected rigid networks showed no decrease in CO2/CH4 ideal selectivity under 690 kPa (100 psig) pure CO2 pressure and also no CO2 plasticization up to 3447 kPa (500 psig) pure CO2 pressure. By using the method of chemical cross-linking as described in this invention, the separation characteristics of the polymeric membranes can be decisively improved. These new cross-linked polymeric membranes can be used not only for gas separations such as CO2/CH4 and CO2/N2 separations, O2/N2 separation, olefin/paraffin separations (e.g. propylene/propane separation), iso/normal paraffins separations, but also for liquid separations such as pervaporation and desalination.
摘要:
Described herein is a cell tissue gel cross-linked with a cross-linking agent, and a quenching agent bound to a reactive group of the cross-linking agent.
摘要:
The invention relates to substantially photochemically or thermally cross-linked polysaccharide derivatives in which the OH groups as OR groups have been esterified or converted into carbamate (urethane) or mixtures thereof and that do not contain photopolymerisable functional groups prior to the cross-linking. They can be used as carrier materials for the chromatographic separation of enantiomers.
摘要:
A method of improving a strength property of a sheet-formed fibrous material formed from an aqueous slurry of cellulose fiber, including coating at least one face of the material with a coating formulation including a polysaccharide containing at least two carboxylic groups and low molecular weight organic mono-, di- or poly-carboxylic acid in an aqueous carrier, keeping the coated face at a temperature of 50° C. or more for a time sufficient to obtain the desired improvement including drying of the material.