摘要:
A process for the reduction of the residual monomer content and enhancement of the wet strength of articles formed from water absorbent crosslinked polymer foams containing units derived from monoethylenically unsaturated acids, which comprises treating the formed articles with at least 0.5% by weight of a polymer containing primary and/or secondary amino groups and having a molar mass of at least 300, the formed foam articles thus obtainable and use of the wet strength enhanced formed foam articles in hygiene articles.
摘要:
Water-absorbing, expanded, crosslinked polymers obtainable by (I) foaming a polymerizable aqueous mixture which comprises (a) monoethylenically unsaturated monomers which contain acidic groups and are optionally neutralized, (b) optionally other monoethylenically unsaturated monomers, (c) crosslinkers, (d) initiators, (e) 0.1-20% by weight of at least one surfactant, (f) optionally at least one solubilizer and (g) optionally thickeners, foam stabilizers, polymerization regulators, fillers and/or cell nucleating agents, where the foaming takes place by dissolving a gas which is inert to free radicals under a pressure of 2-400 bar in the polymerizable aqueous mixture, and then decompressing the latter to atmospheric pressure, and (II) polymerizing the foamed mixture to form an expanded hydrogel and, where appropriate, adjusting the water content of the expanded polymer to 1-60% by weight, process for preparing the water-absorbing, expanded, crosslinked polymers and use of these polymers in sanitary articles employed for absorbing body fluids, in dressing material for covering wounds, as sealing material, as soil improver, as soil substitute and as packaging material.
摘要:
A water-absorbing, expanded, crosslinked polymer obtainable by (I) foaming a polymerizable aqueous mixture which comprises (a) monoethylenically unsaturated monomers which contain acidic groups and are optionally neutralized, (b) optionally other monoethylenically unsaturated monomers, (c) crosslinkers, (d) initiators, (e) 0.1-20% by weight of at least one surfactant, (f) optionally at least one solubilizer and (g) optionally thickeners, foam stabilizers, polymerization regulators, fillers and/or cell nucleating agents, where the foaming takes place by dispersing fine bubbles of a gas which is inert to free radicals in the polymerizable aqueous mixture, and (II) polymerizing the foamed mixture to form an expanded hydrogel, whereby at least 20 mol % of the monomers (a) which contain acidic groups have been neutralized with tertiary alkanolamines and/or the free acidic groups of the expanded hydrogel have been at least 20 mol % neutralized with at least one alkalolamine after the polymerization, and, where appropriate, adjusting the water content of the expanded polymer to 1-60% by weight, the production thereof and the use thereof in hygiene articles employed to absorb body fluids and in dressing material for covering wounds.
摘要:
Absorber elements are described of at least one composite material having absorbent elements on a support, in which a plurality of elements of a superabsorbent foam are arranged on at least one support in a grid pattern at distances such that the elements in the swollen state touch at their peripheries.
摘要:
Disclosed is a method for determining the swellability and the swelling kinetics of superabsorbent material (9) such as polymer gels, for example, which comprises introducing a defined volume of the dry superabsorbent material (9) into a measuring vessel (7), using a movable element (4) within said measuring vessel (7) to apply a restraining force (12) to said superabsorbent material (9) and capturing the expansion of said superabsorbent material (9) contactlessly within a chamber (14) in a continuous manner by capturing the change in height of a piston (4) which bounds said chamber (14), travels in a measuring vessel (7) and is marked with a height scale (6).
摘要:
Foams composed of water-absorbing basic polymers, obtainable by (I) foaming a crosslinkable aqueous mixture including (a) at least one basic polymer whose basic groups have optionally been neutralized, (b) at least one crosslinker, (c) at least one surfactant, (d) optionally at least one solubilizer, (e) optionally thickeners, foam stabilizers, fillers, fibers and/or cell nucleators, and (f) optionally particulate water-absorbing acidic polymers, by dissolving a gas which is inert toward free radicals in the crosslinkable aqueous mixture under a pressure from 2 to 400 bar and subsequently decompressing the crosslinkable aqueous mixture to atmospheric or by dispersing fine bubbles of a gas which is inert toward free radicals, and (II) crosslinking the foamed mixture to form a hydrogel foam and if applicable adjusting the water content of the polymer foam to 1-60% by weight. Preparation of the foams by application of the abovementioned measures (I) and (II) and use of the thus obtainable foams in hygiene articles to absorb body fluids, in dressing material to cover wounds, as a sealing material, as a packaging material, as a soil improver, as a soil substitute, to dewater sludges, to absorb aqueous acidic wastes, to thicken waterborne paints or coatings in the course of disposing of residual quantities thereof, to dewater water-containing oils or hydrocarbons or as a material for filters in ventilation systems.
摘要:
Thermoplastic molding compositions comprising A) from 10 to 99% by weight of a polyamide, B) from 0.1 to 20% by weight of B1) a polyacrylamide or B2) a polyvinylamide, or a mixture of these, C) from 0 to 70% by weight of further additives, where the total of the percentages by weight of components A) to C) is 100%.
摘要:
Hydrophilic open-celled resilient foams containing melamine-formaldehyde resins, characterized by a droplet absorption rate of less than 5 seconds and an EU standard EN ISO 14184-1 formaldehyde emission of less than 100 mg of formaldehyde/kg of foam, and obtainable by (a) heating an aqueous solution or dispersion each containing at least a melamine-formaldehyde precondensate, an emulsifier, a blowing agent and a curing agent to form a foam and crosslink the precondensate, (b) then conditioning the foam at from 120 to 300° C. for from 1 to 180 minutes to remove volatiles, and (c) treating the foam during the conditioning or thereafter with at least one hydrophilicizer and/or with ozone, a corona discharge or a plasma, are useful in hygiene articles to acquire, distribute and immobilize body fluids.
摘要:
Use in hygiene articles of articles formed of water-absorbent, predominantly open-celled crosslinked acid-functional addition polymer foams Abstract The use of articles formed of water-absorbent open-celled crosslinked acid-functional addition polymer foams and containing finely divided silicon dioxide and/or at least one surfactant on their surface as an acquisition and/or distribution layer in hygiene articles.