As a method for producing a copolymer with a high oil absorption rate by separating a solvent from a copolymer solution containing a copolymer in a simple manner with a less energy consumption, the present invention relates to a production method for obtaining a copolymer by separating a solvent from a copolymer solution, the method including the following Steps A to C. Step A: a step of regulating a solid component concentration (Ts) of the copolymer solution to a range of (5≦Ts≦60) in terms of a mass %, Step B: a step of heating the copolymer (P) solution obtained in the Step A such that a temperature T (° C.) is in a specified range, and Step C: a step of discharging the copolymer solution heated in the Step B from a specified nozzle at a linear velocity of 1 to 100 m/sec to separate the solvent in an inert gas stream at 0 to 200° C.

As a method for producing a copolymer with a high oil absorption rate by separating a solvent from a copolymer solution containing a copolymer in a simple manner with a less energy consumption, the present invention relates to a production method for obtaining a copolymer by separating a solvent from a copolymer solution, the method including the following Steps A to C. Step A: a step of regulating a solid component concentration (Ts) of the copolymer solution to a range of (5≦Ts≦60) in terms of a mass %, Step B: a step of heating the copolymer (P) solution obtained in the Step A such that a temperature T (° C.) is in a specified range, and Step C: a step of discharging the copolymer solution heated in the Step B from a specified nozzle at a linear velocity of 1 to 100 m/sec to separate the solvent in an inert gas stream at 0 to 200° C.

A material includes nonwoven fibers and a surface modification that crosslinks the nonwoven fibers together. The surface modification can include chemical reactive groups. The reactive groups can be selected from diisocyanates, alcohols, epoxides, imides, amides, imines, amines, diacrylates, disiloxanes and disilazanes. A method of forming the material electrospins fiber material in the form of fibers into a nonwoven material. A surface modification is introduced to the fibers either by modifying the fiber material before the electrospinning or by modifying the fiber surface after the electrospinning. The fibers are crosslinked to form the crosslinked nonwoven material.

A composition can include a carbon nanofiber, wherein a precursor for the carbon nanofiber includes an alcohol and an aldehyde crosslinked by a primary amine. In certain embodiments, the carbon nanofiber can be biotemplated. Biotemplating enables precise control of morphology at the nanometer scale, while molecular templating allows control of carbon nanotexture and structure at the sub-nanometer scale.

The present disclosure relates to a device and a process for cutting hollow fiber membranes having a large inner diameter.

The present disclosure relates to a device and a process for cutting hollow fiber membranes having a large inner diameter.

A method for producing a polyurethane elastic fiber according to the present invention contains the steps of: [1] producing a polyurethane urea polymer (A) having a number average molecular weight ranging from 12,000 to 50,000, and represented by general formula (1); [2] preparing a spinning dope by adding the polyurethane urea polymer (A) to a polyurethane urea polymer (B); and [3] spinning a polyurethane elastic fiber using the spinning dope. ##STR00001##
In the formula, R.sup.1 and R.sup.2 are an alkyl group or a hydroxyalkyl group, R.sup.3 is an alkylene group, a polyethyleneoxy group or a polypropyleneoxy group, R.sup.4 is a diisocyanate residue, X is a urethane bond or a urea bond, R.sup.5 and R.sup.6 are a diisocyanate residue, P is a diol residue, Q is a diamine residue, UT is a urethane bond, UA is a urea bond, each of k, 1, m and n is 0 or a positive number.

A method for producing a polyurethane elastic fiber according to the present invention contains the steps of: [1] producing a polyurethane urea polymer (A) having a number average molecular weight ranging from 12,000 to 50,000, and represented by general formula (1); [2] preparing a spinning dope by adding the polyurethane urea polymer (A) to a polyurethane urea polymer (B); and [3] spinning a polyurethane elastic fiber using the spinning dope. ##STR00001##
In the formula, R.sup.1 and R.sup.2 are an alkyl group or a hydroxyalkyl group, R.sup.3 is an alkylene group, a polyethyleneoxy group or a polypropyleneoxy group, R.sup.4 is a diisocyanate residue, X is a urethane bond or a urea bond, R.sup.5 and R.sup.6 are a diisocyanate residue, P is a diol residue, Q is a diamine residue, UT is a urethane bond, UA is a urea bond, each of k, 1, m and n is 0 or a positive number.

The disclosure provides a method for preparing a hollow fiber membrane by melt spinning-stretching and selective swelling, including: preparing a nascent hollow fiber by melt spinning in an inert gas protective atmosphere by using an amphiphilic block copolymer as a film forming material, and stretching the nascent hollow fiber in the cooling process, a stretch rate being controlled at 200-540 mm/min, and a stretch ratio being controlled at 150-600%; immersing the obtained hollow fiber in a swelling solvent, and treating the hollow fiber in a water bath at 65° C. for 1 h; and then transferring the hollow fiber into a long-chain alkane solvent, treating the hollow fiber at the same temperature for 1-12 h, and after the completion of the treatment, immediately taking out the hollow fiber and drying the hollow fiber to obtain the hollow fiber membrane with a bicontinuous porous structure. By combining the melt spinning-stretching and the selective swelling, the method of the disclosure can synchronously and continuously improve the permeability and selectivity of the hollow fiber membrane. The treatment in the long-chain alkane solvent can make the polar chain excessively enriched on the surface of the membrane migrate inward, thereby improving the performance of the hollow fiber membrane.

Described herein are polyphenylene fibers. The polyphenylene fibers have one or more polyphenylene polymers. The polyphenylene fibers can further include one or more poly(aryl ether sulfone) polymers. In some embodiments, the polyphenylene fibers can have an average diameter that is less than about 1 micron. The polyphenylene fibers can have desirable mechanical properties. Also described herein are methods for forming polyphenylene fibers. In some embodiments, the fibers can be fabricated using specifically engineered polymer solutions in conjunctions with adapted force spinning techniques.