Manufacturing method for polyacrylonitrile-based carbon fiber protofilament

Abstract

The invention provides a preparation method for a polyacrylonitrile-based carbon fiber protofilament. The third monomer of a spinning raw material polyacrylonitrile resin is itaconic acid. The preparation method comprises the following successive steps: preparing a spinning solution from the resin by using an aqueous solution of NaSCN and carrying out spinning and solidification so as to prepare a nascent fiber; placing the nascent fiber in the aqueous solution of NaSCN for water bath drafting and carrying out drip washing with deionized water; dipping the nascent fiber in an acidic aqueous solution; dipping the nascent fiber in a sodium hydroxide or potassium hydroxide aqueous solution; placing the nascent fiber in pure water for water bath drafting; subjecting the nascent fiber to hot bath rinsing until rinsing liquid is neutral and sodium or potassium ions cannot be measured, and then continuing rinsing for 5 to 15 min; and carrying out post-processing procedures like oiling and dry densification on the nascent fiber so as to obtain a product of the polyacrylonitrile-based carbon fiber protofilament. According to the invention, purification of the protofilament is realized through rinsing, and breaking strength of fibers is not affected, so the defects of the prior art are overcome.

Description

technical field

[0001] The invention relates to a method for manufacturing polyacrylonitrile-based carbon fiber precursors, in particular to using itaconic acid as a third comonomer of polyacrylonitrile resin as a spinning raw material to produce polyacrylonitrile-based carbon fiber precursors through a solution spinning process Methods. Background technique

[0002] Carbon fiber has excellent mechanical properties, and its extremely high specific strength and specific modulus are incomparable to other materials. As a reinforcing material, it is widely used in the fields of aerospace, aircraft and sports equipment manufacturing. Carbon fibers are usually made from pre-oxidized and carbonized precursors made of carbonizable substances. Because polyacrylonitrile resins have a high carbonization yield, polyacrylonitrile fibers are very ideal carbon fiber precursors. The prepared carbon fibers It is called polyacrylonitrile-based carbon fiber.

[0003] In order to obtain polya...

Examples

Embodiment 1～12

[0035] Carry out the preparation of carbon fiber precursor according to the following steps:

[0036] 1) The polyacrylonitrile resin is prepared into a spinning solution with 45-58wt% NaSCN aqueous solution as a solvent, and the content of the polyacrylonitrile resin in the spinning solution is 10-14wt%. Using 8-16wt% NaSCN aqueous solution as a coagulation bath, adopting a wet spinning process to produce primary fibers through spinning and coagulation forming;

[0037] 2) The as-spun fiber is drawn in a water bath in 1 to 5 wt% NaSCN aqueous solution. The water bath temperature and the draw ratio of each embodiment are shown in Table 1, and this step is defined as pre-drawing in the table;

[0038] 3) The as-spun fibers are rinsed with deionized water, the water temperature is controlled at 45-60°C, and the rinse time is controlled at 2-20 minutes;

[0039] 4) The as-spun fiber is placed in the acidic aqueous solution for immersion, the control data of the acid and pH value,...

technical field

[0001] The invention relates to a method for manufacturing polyacrylonitrile-based carbon fiber precursors, in particular to using itaconic acid as a third comonomer of polyacrylonitrile resin as a spinning raw material to produce polyacrylonitrile-based carbon fiber precursors through a solution spinning process Methods. Background technique

[0002] Carbon fiber has excellent mechanical properties, and its extremely high specific strength and specific modulus are incomparable to other materials. As a reinforcing material, it is widely used in the fields of aerospace, aircraft and sports equipment manufacturing. Carbon fibers are usually made from pre-oxidized and carbonized precursors made of carbonizable substances. Because polyacrylonitrile resins have a high carbonization yield, polyacrylonitrile fibers are very ideal carbon fiber precursors. The prepared carbon fibers It is called polyacrylonitrile-based carbon fiber.

[0003] In order to obtain polya...

Examples

Embodiment 1～12

[0035] Carry out the preparation of carbon fiber precursor according to the following steps:

[0036] 1) The polyacrylonitrile resin is prepared into a spinning solution with 45-58wt% NaSCN aqueous solution as a solvent, and the content of the polyacrylonitrile resin in the spinning solution is 10-14wt%. Using 8-16wt% NaSCN aqueous solution as a coagulation bath, adopting a wet spinning process to produce primary fibers through spinning and coagulation forming;

[0037] 2) The as-spun fiber is drawn in a water bath in 1 to 5 wt% NaSCN aqueous solution. The water bath temperature and the draw ratio of each embodiment are shown in Table 1, and this step is defined as pre-drawing in the table;

[0038] 3) The as-spun fibers are rinsed with deionized water, the water temperature is controlled at 45-60°C, and the rinse time is controlled at 2-20 minutes;

[0039] 4) The as-spun fiber is placed in the acidic aqueous solution for immersion, the control data of the acid and pH value,...

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