The invention relates to process for preparing a flame resistant and/or flame retardant polymer, comprising reacting an acrylonitrile polymer with an organic diamine.

The invention relates to process for preparing a flame resistant and/or flame retardant polymer, comprising reacting an acrylonitrile polymer with an organic diamine.

In order to provide a method for preparing a chalcogenide-carbon nanofiber, capable of implementing oxidation resistance characteristics and process simplification, the present invention provides a method for preparing a chalcogenide-carbon nanofiber and a chalcogenide-carbon nanofiber implemented by using the same, the method comprising the steps of: forming a chalcogenide precursor-organic nanofiber comprising a chalcogenide precursor and an organic material; and forming a chalcogenide-carbon nanofiber by selectively and oxidatively heat treating the chalcogenide precursor-organic nanofiber such that the carbon of the organic material is oxidized and the chalcogenide is reduced at the same time, wherein the oxidation reactivity of the chalcogenide is lower than that of carbon, the selective and oxidative heat treatment is carried out through one heat treatment step instead of a plurality of heat treatment steps, and the chalcogenide can form a chalcogenide-carbon nanofiber having a structure formed with at least one layer according to an oxygen partial pressure at which the selective and oxidative heat treatment is carried out.

In order to provide a method for preparing a chalcogenide-carbon nanofiber, capable of implementing oxidation resistance characteristics and process simplification, the present invention provides a method for preparing a chalcogenide-carbon nanofiber and a chalcogenide-carbon nanofiber implemented by using the same, the method comprising the steps of: forming a chalcogenide precursor-organic nanofiber comprising a chalcogenide precursor and an organic material; and forming a chalcogenide-carbon nanofiber by selectively and oxidatively heat treating the chalcogenide precursor-organic nanofiber such that the carbon of the organic material is oxidized and the chalcogenide is reduced at the same time, wherein the oxidation reactivity of the chalcogenide is lower than that of carbon, the selective and oxidative heat treatment is carried out through one heat treatment step instead of a plurality of heat treatment steps, and the chalcogenide can form a chalcogenide-carbon nanofiber having a structure formed with at least one layer according to an oxygen partial pressure at which the selective and oxidative heat treatment is carried out.

The present invention relates to hybrid sheet comprising: i) high-performance polyethylene (HPPE) fibers; ii) a polymeric resin, wherein the polymeric resin is selected from a group consisting of a homopolymer of ethylene, a homopolymer of propylene, a copolymer of ethylene, and a copolymer of propylene and wherein said polymeric resin has a density as measured according to ISO1183-2004 in the range from 860 to 970 kg/m.sup.3, a peak melting temperature in the range from 40 to 140 C. and a heat of fusion of at least 5 J/g; iii) non-polymeric fibers; and iv) optionally, a matrix material. Furthermore, the present invention relates to a process to manufacture the hybrid sheet and to the use of the hybrid sheet in various fields, such as in automotive field, in aerospace field, in sports equipment, in marine field, in military field; and in wind and renewable energy field.

The present invention relates to hybrid sheet comprising: i) high-performance polyethylene (HPPE) fibers; ii) a polymeric resin, wherein the polymeric resin is selected from a group consisting of a homopolymer of ethylene, a homopolymer of propylene, a copolymer of ethylene, and a copolymer of propylene and wherein said polymeric resin has a density as measured according to ISO1183-2004 in the range from 860 to 970 kg/m.sup.3, a peak melting temperature in the range from 40 to 140 C. and a heat of fusion of at least 5 J/g; iii) non-polymeric fibers; and iv) optionally, a matrix material. Furthermore, the present invention relates to a process to manufacture the hybrid sheet and to the use of the hybrid sheet in various fields, such as in automotive field, in aerospace field, in sports equipment, in marine field, in military field; and in wind and renewable energy field.

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.

A preparation method of PVA fiber comprises the following steps: preparing a spinning dope; PVAc is used as a raw material, and dissolved with addition of methanol before filtration, and then the spinning dope is obtained; spinning; the spinning dope is injected into a spinneret, and the ejected fibers are brought into a direct current electrolytic cell, and undergo a series of reactions of alcoholysis, electrolytic catalytic alcoholysis, and the levering of the alcohol; and the solution formulation in the electrolytic coagulation bath comprises alkali, alcohol and water; acid bath; through stretching, drying, washing with water, crimping with hot water and packaging, a finished polyvinyl alcohol fiber product is formed. The mirabilite is not needed in the coagulation bath, and PVA is obtained by the alcoholysis of PVAc in an electrolytic cell, and the produced PVA fibers present high purity and few impurities.

A polyvinyl alcohol fiber that can easily be fibrillated at a low manufacture cost is provided. The readily fibrillative polyvinyl alcohol fiber contains a polyalkylene oxide in addition to a polyvinyl alcohol. A mass ratio of the polyalkylene oxide ranges from 3 to 40% relative to the total mass of the polyvinyl alcohol and the polyalkylene oxide. A method for manufacturing the polyvinyl alcohol fiber is also provided.