A foamable filament composition comprising a single polymer or blend of polymers and a foaming agent having an activation temperature, wherein the single polymer or blend of polymers has a sufficient molecular weight to allow for polymer chain entanglement, and wherein the single polymer or polymer blend is melt-processable at a temperature below the activation temperature of the foaming agent.

A foamable filament composition comprising a single polymer or blend of polymers and a foaming agent having an activation temperature, wherein the single polymer or blend of polymers has a sufficient molecular weight to allow for polymer chain entanglement, and wherein the single polymer or polymer blend is melt-processable at a temperature below the activation temperature of the foaming agent.

The present application discloses a method for preparing microporous PVA fiber comprising the following steps: Step 1: preparing spinning solution, calcium hydroxide solution, and sodium sulfate solution; Step 2: cooling the spinning solution to 40-60° C., and adding a foaming agent thereto to provide the PVA spinning stock solution; Step 3: spinning into the sodium sulfate solution so that the fiber containing the reaction product of the foaming agent and the mirabilite is dehydrated to provide a primary PVA fiber; Step 4: reacting the fiber with the calcium hydroxide solution to provide a secondary fiber; Step 5: foaming and pore forming; and Step 6: cleaning and drying to provide the final product of microporous PVA fiber.

The present application discloses a method for preparing microporous PVA fiber comprising the following steps: Step 1: preparing spinning solution, calcium hydroxide solution, and sodium sulfate solution; Step 2: cooling the spinning solution to 40-60° C., and adding a foaming agent thereto to provide the PVA spinning stock solution; Step 3: spinning into the sodium sulfate solution so that the fiber containing the reaction product of the foaming agent and the mirabilite is dehydrated to provide a primary PVA fiber; Step 4: reacting the fiber with the calcium hydroxide solution to provide a secondary fiber; Step 5: foaming and pore forming; and Step 6: cleaning and drying to provide the final product of microporous PVA fiber.

The present invention provides a porous carbon fiber which has an excellent permeation amount and excellent pressure resistance, which is prevented from the occurrence of detachment or cracking at an interface, and which can exhibit excellent properties needed for use as a support for a fluid separation membrane. The present invention is a porous carbon fiber having a bicontinuous porous structure, wherein the average value R.sub.ave of the R value of the outer surface and the R value of the inside is 1.0 or more and 1.8 or less, the absolute value ΔR of the difference between the R value of the outer surface and the R value of the inside is 0.05 or less, and R value is a carbonization progression degree calculated from a Raman spectrum in accordance with the following formula:
R value=(intensity of scattering spectrum at 1360 cm.sup.−1)/(intensity of scattering spectrum at 1600 cm.sup.−1).

The present invention provides a porous carbon fiber which has an excellent permeation amount and excellent pressure resistance, which is prevented from the occurrence of detachment or cracking at an interface, and which can exhibit excellent properties needed for use as a support for a fluid separation membrane. The present invention is a porous carbon fiber having a bicontinuous porous structure, wherein the average value R.sub.ave of the R value of the outer surface and the R value of the inside is 1.0 or more and 1.8 or less, the absolute value ΔR of the difference between the R value of the outer surface and the R value of the inside is 0.05 or less, and R value is a carbonization progression degree calculated from a Raman spectrum in accordance with the following formula:
R value=(intensity of scattering spectrum at 1360 cm.sup.−1)/(intensity of scattering spectrum at 1600 cm.sup.−1).

A process for forming an extruded composition using a wet-spin dry-jet technique including forming a dispersion dope by mixing phase change material with a first portion of solvent, and sonicating the mixture, forming a prime dope by combining a first portion of polymer and a second portion of solvent, forming an extrusion composition by combining the dispersion dope, the prime dope and a second portion of the polymer, rolling the extrusion composition, degassing the extrusion composition, extruding the extrusion composition through a spinneret, drying the extruded composition, and quenching the extruded composition. The weight fraction of the phase change material in the extruded composition can be greater than approximately 60%, and preferably greater than approximately 75%.

A method of producing a functionalized material that extracts metal ions from solution, the method comprising: (i) providing a precursor material having nitrile groups appended to its surface; and (ii) reacting said nitrile groups with hydroxylamine or a derivative thereof in the presence of a polar aprotic solvent at a temperature of 60-80° C. for at least 1 hour, to convert at least a portion of said nitrile groups to amidoxime and imide dioxime groups, followed by reaction with a base capable of hydrolyzing any remaining nitrile groups to carboxylic acid groups; wherein said functionalized material has a higher uranium absorption capacity than a functionalized material produced under same conditions except that the nitrile groups are reacted with hydroxylamine in only a protic solvent. The invention is also directed to functionalized materials produced by the above-described method, and methods for using the functionalized material for extracting metal ions from metal-containing solutions.

A polyolefin material that comprises a thermoplastic composition that is annealed and thereafter drawn in a solid state is provided. The composition contains a continuous phase that includes a polyolefin matrix polymer and a nanoinclusion additive dispersed within the continuous phase in the form of discrete domains. A porous network is defined within the thermoplastic composition that includes a plurality of nanopores, wherein the thermoplastic composition has a glass transition temperature of from about −20° C. to about 50° C. as determined in accordance with ASTM E1640-13.

A polyolefin material that comprises a thermoplastic composition that is annealed and thereafter drawn in a solid state is provided. The composition contains a continuous phase that includes a polyolefin matrix polymer and a nanoinclusion additive dispersed within the continuous phase in the form of discrete domains. A porous network is defined within the thermoplastic composition that includes a plurality of nanopores, wherein the thermoplastic composition has a glass transition temperature of from about −20° C. to about 50° C. as determined in accordance with ASTM E1640-13.