Abstract:
Disclosed is a method for generating macroporous polymeric crosslinked materials and the materials obtained therewith. The method uses beads of reversible hydrogels or selected core-shell beads as pore forming materials which are introduced as solid beads into a liquid of polymerisable monomers, for example via a drop-on-demand technique. After the polymerisation of the monomers the solid beads are liquefied and the pore-forming material is removed from the polymer matrix. This technique allows formation of macropores with uniform diameter and with a high amount of macropores being in fluid communication with each other. The macroporous polymeric crosslinked materials, preferably in the form of hydrogels, can be used as substrates in tissue-engineering.
Abstract:
A porous polymer blend, and a method of producing a porous polymer blend from at least two immiscible polymers. The at least two immiscible polymer being blended together and exhibiting the absence of complete phase separation. The method of producing a porous polymer blend comprising: forming a liquid composition comprising at least two immiscible polymers dissolved in a common solvent; subjecting the liquid composition to a reduction in temperature to cause at least two immiscible polymers to phase separate into a common polymer rich phase and a common polymer poor phase; solidifying the at least two immiscible polymers in the common polymer rich phase so as to avoid complete phase separation of the at least two immiscible polymers; and removing the common polymer pore phase to provide a blend of the at least two immiscible polymers having a porous morphology.
Abstract:
Microporous articles are formed by solid-liquid phase separation from a diluent in combination with a thermoplastic polymer, flame retardant and a hindered amine synergist providing novel flame retardant articles. Such articles are useful in clothing, barriers, optical films in electronic devices (such as light reflective and dispersive films), printing substrates and electrical insulation.
Abstract:
Porous material of a polysaccharide and a method for preparations of such a material, wherein a water-based solution of the polysaccharide is mixed, with controlled stirring, with an essentially water-immiscible organic phase to form an emulsion, which when allowed to solidify, just before or during the gelling process, forms a network of two continuous phases, an aqueous polysaccharide phase and a flow-pore-forming organic phase, resulting in a material with two types of pores: small diameter diffusion pores and large diameter flow through pores.
Abstract:
A method of preparing a porous polymer structure comprising the steps of: forming a liquid composition comprising at least one polymer dissolved in at least one solvent; subjecting the liquid composition to stress, and if necessary also to a reduction in temperature, to cause the liquid composition to form a bi-continuous phase separated composition, the bi-continuous phase separated composition comprising a polymer rich phase and a polymer poor phase; solidifying the at least one polymer in the polymer rich phase; and removing the polymer poor phase from the polymer rich phase to provide the porous polymer structure having a bi-continuous morphology from the polymer rich phase.
Abstract:
Microporous articles are formed by solid-liquid phase separation from a diluent in combination with a thermoplastic polymer, flame retardant and a hindered amine synergist providing novel flame retardant articles. Such articles are useful in clothing, barriers, optical films in electronic devices (such as light reflective and dispersive films), printing substrates and electrical insulation.
Abstract:
Microporous materials and articles are disclosed. The microporous materials contain a crystallizable propylene-containing polymer, a beta-nucleating agent, and a diluent that is miscible with the polymer at a temperature above the melting temperature of the polymer and that phase separates from the polymer at a temperature below the polymer crystallization temperature. The invention is also directed to methods of forming the microporous material using thermal induced phase separation and subsequent processing.
Abstract:
Briefly, in one aspect, the present invention provides puncture resistant microporous materials made of melt-processable semi-crystalline thermoplastic polymers. The microporous materials can be produced at relatively high rates and at low cost. Films and multilayer constructions made of the microporous materials and methods of making microporous materials also are provided.
Abstract:
Disclosed is an absorbent foam that exhibits desirable softness and flexibility properties yet is highly absorbent. In one embodiment, the absorbent foam comprises a water-swellable, water-insoluble polymer wherein the absorbent foam exhibits a Free Swell value of at least about 10 grams of liquid per gram of absorbent foam and a Softness value that is less than about 30 grams of force per gram per square meter of absorbent foam. In a second embodiment, the absorbent foam has an average cell size of the cells in the absorbent foam between about 10 microns to about 100 microns and an average wall thickness of the cells in the absorbent foam between about 0.1 micron to about 30 microns. Such an absorbent foam may be used in a disposable absorbent product intended for the absorption of fluids such as body fluids. Also disclosed is a process for preparing an absorbent foam. The process generally comprises forming a solution of a polymer in a solvent, freezing the solution at a relatively slow cooling rate to a temperature below the freezing point of the solvent, removing the solvent from the frozen solution, and recovering the polymer to form a water-swellable, water-insoluble polymeric foam.