Continuous large-scale production method for p-aramid nanofiber dispersion liquid

Abstract

The invention relates to a continuous large-scale production method for p-aramid nanofiber dispersion liquid, and belongs to the technical field of novel polymer materials. A proper aid is added in a process of generating poly-p-phenylene terephthamide (PPTA) through a reaction of p-phenylenediamine and paraphthaloyl chloride, so that the PPTA can directly generate nanofiber instead of random particles under control. Double screws are taken as a main reactor of PPTA polymerization, and an aid damaging molecular molecular aggregation of the PPTA is added into a PPTA polymerization system, so that successful proceeding of a PPTA polymerization process can be ensured on the one hand, interaction between the aid and the PPTA can be accelerated under the strong shear stirring action of a screw element on the other hand, and uniform nanofiber is formed instead of random particles by the PPTA. Moreover, a dispersing process of the nanofiber is finished directly in the screws under the shearing action of the double screws. The method is simple in equipment and is urgent in production links, major reaction and dispersion processes are finished in the double screws, and the production stability and continuity are enhanced greatly.

Description

technical field

[0001] The invention relates to a continuous large-batch preparation method of a para-aramid fiber nanofiber dispersion, belonging to the technical field of new polymer materials. Background technique

[0002] Para-aramid fiber has excellent properties such as high strength, high modulus and high temperature resistance, and is widely used in special clothing, aerospace, sporting goods, cables and composite materials and other fields. Para-aramid nanofibers (hereinafter referred to as PANF) not only have the advantages of para-aramid fibers, but also are easier to disperse, easy to compound with other materials, have good heat insulation and oxidation resistance, and can be used as electrical insulation materials, Honeycomb structure materials and filter materials have broad application prospects in the fields of batteries, supercapacitors, high-temperature resistant filters, and electrical components.

[0003] At present, various methods such as electrospinn...

Examples

preparation example Construction

[0016] The continuous mass preparation method of para-aramid fiber nanofiber dispersion that the present invention proposes comprises the following steps:

[0017] (1) Ingredients:

[0018] (1-1) Add the solvent N-methylpyrrolidone into the dissolution kettle, and add the solubilizing salt while stirring under the protection of nitrogen, and heat to 70-110°C to dissolve the solubilizing salt to obtain the first solution; The solubilizing salt is calcium chloride or lithium chloride, or a mixture of calcium chloride and lithium chloride mixed in any proportion, and the weight ratio of the solvent to the solubilizing salt is: solvent: solubilizing salt=1: (0.05~0.15) ;

[0019] (1-2) Cool the first solution in the reaction kettle of the above step (1-1) to 0-25°C, add p-phenylenediamine and auxiliary agent while stirring, and obtain p-phenylenediamine and auxiliary agent after dissolving Phenylenediamine solution, the temperature of the p-phenylenediamine solution is lowered t...

Embodiment 1

[0028] (1) Add 450L of solvent N-methylpyrrolidone into a 600L dissolution kettle, and add 45kg of calcium chloride, a solubilizing salt, under nitrogen protection and stirring, and heat at 100°C to dissolve the solubilizing salt. Then the temperature of the dissolution tank was lowered to 15° C., and 19.467 kg of p-phenylenediamine and 20 kg of terminal methyl polyoxyethylene ether with a molecular weight of 2000 were added under stirring for dissolution. Then cool down the dissolution tank to 0°C, meter it through the transfer pump and flowmeter and transfer it to the mixer; the terephthaloyl chloride melt at 90°C is also metered and transferred to the mixer through the transfer pump and flowmeter device. The monomer molar ratio is controlled by accurate metering to be terephthaloyl chloride: p-phenylenediamine = 1.007:1.

[0029] (2) The mixed liquor flows down to a single-stage screw reactor by gravity. The screw aspect ratio is 68:1. The aspect ratio of the reaction zo...

Embodiment 2

[0032] (1) Add 450L of solvent N-methylpyrrolidone into a 600L dissolution kettle, and add 40Kg of calcium chloride, a solubilizing salt, under nitrogen protection and stirring, and heat at 100°C to dissolve the solubilizing salt. Then the temperature of the dissolution tank was lowered to 15° C., and 24.332 Kg of p-phenylenediamine was added under stirring for dissolution. Then cool down the dissolution tank to 0°C, add 30kg of double-ended methyl polyoxyethylene ether with a molecular weight of 6000 to dissolve, then meter it and transport it to the mixer through a delivery pump and flow meter; The formyl chloride melt is also metered and delivered to the mixer by a transfer pump and flow meter. The monomer molar ratio is controlled by accurate metering to be terephthaloyl chloride: p-phenylenediamine = 1.005:1.

[0033] (2) The mixed solution is transported to a two-stage screw reactor through a gear pump. Among them, the first-order machine is used for PPTA polymerizatio...

technical field

[0001] The invention relates to a continuous large-batch preparation method of a para-aramid fiber nanofiber dispersion, belonging to the technical field of new polymer materials. Background technique

[0002] Para-aramid fiber has excellent properties such as high strength, high modulus and high temperature resistance, and is widely used in special clothing, aerospace, sporting goods, cables and composite materials and other fields. Para-aramid nanofibers (hereinafter referred to as PANF) not only have the advantages of para-aramid fibers, but also are easier to disperse, easy to compound with other materials, have good heat insulation and oxidation resistance, and can be used as electrical insulation materials, Honeycomb structure materials and filter materials have broad application prospects in the fields of batteries, supercapacitors, high-temperature resistant filters, and electrical components.

[0003] At present, various methods such as electrospinn...

Examples

preparation example Construction

[0016] The continuous mass preparation method of para-aramid fiber nanofiber dispersion that the present invention proposes comprises the following steps:

[0017] (1) Ingredients:

[0018] (1-1) Add the solvent N-methylpyrrolidone into the dissolution kettle, and add the solubilizing salt while stirring under the protection of nitrogen, and heat to 70-110°C to dissolve the solubilizing salt to obtain the first solution; The solubilizing salt is calcium chloride or lithium chloride, or a mixture of calcium chloride and lithium chloride mixed in any proportion, and the weight ratio of the solvent to the solubilizing salt is: solvent: solubilizing salt=1: (0.05~0.15) ;

[0019] (1-2) Cool the first solution in the reaction kettle of the above step (1-1) to 0-25°C, add p-phenylenediamine and auxiliary agent while stirring, and obtain p-phenylenediamine and auxiliary agent after dissolving Phenylenediamine solution, the temperature of the p-phenylenediamine solution is lowered t...

Embodiment 1

[0028] (1) Add 450L of solvent N-methylpyrrolidone into a 600L dissolution kettle, and add 45kg of calcium chloride, a solubilizing salt, under nitrogen protection and stirring, and heat at 100°C to dissolve the solubilizing salt. Then the temperature of the dissolution tank was lowered to 15° C., and 19.467 kg of p-phenylenediamine and 20 kg of terminal methyl polyoxyethylene ether with a molecular weight of 2000 were added under stirring for dissolution. Then cool down the dissolution tank to 0°C, meter it through the transfer pump and flowmeter and transfer it to the mixer; the terephthaloyl chloride melt at 90°C is also metered and transferred to the mixer through the transfer pump and flowmeter device. The monomer molar ratio is controlled by accurate metering to be terephthaloyl chloride: p-phenylenediamine = 1.007:1.

[0029] (2) The mixed liquor flows down to a single-stage screw reactor by gravity. The screw aspect ratio is 68:1. The aspect ratio of the reaction zo...

Embodiment 2

[0032] (1) Add 450L of solvent N-methylpyrrolidone into a 600L dissolution kettle, and add 40Kg of calcium chloride, a solubilizing salt, under nitrogen protection and stirring, and heat at 100°C to dissolve the solubilizing salt. Then the temperature of the dissolution tank was lowered to 15° C., and 24.332 Kg of p-phenylenediamine was added under stirring for dissolution. Then cool down the dissolution tank to 0°C, add 30kg of double-ended methyl polyoxyethylene ether with a molecular weight of 6000 to dissolve, then meter it and transport it to the mixer through a delivery pump and flow meter; The formyl chloride melt is also metered and delivered to the mixer by a transfer pump and flow meter. The monomer molar ratio is controlled by accurate metering to be terephthaloyl chloride: p-phenylenediamine = 1.005:1.

[0033] (2) The mixed solution is transported to a two-stage screw reactor through a gear pump. Among them, the first-order machine is used for PPTA polymerizatio...