RU1821500C - Process for manufacturing high-strength and high-modulus carbon fibers - Google Patents

Abstract

SUMMARY OF THE INVENTION: A starting fiber made in a mixture of polyacrylonitrile and butadiene rubber is subjected to oxidation and carbonization. High strength and high modulus fiber is obtained. The duration of the process is reduced by 2-4 hours.

Description

The invention relates to the production of high-strength carbon materials based on synthetic fibers, in particular based on fibers from a mixture of polyacrylonitrile (PAN) and butadiene rubber (SKN-40).

The invention makes it possible to obtain carbon fibers with increased strength and elastic modulus Over a relatively short time of oxidation and carbonization by using fibers based on PAN and butadiene nitrile rubber (SKN-40) of a wet spinning process. . :

The introduction of a small amount of nitrile rubber into the composition of polyacrylonitrile reduces the oxidation time by 2-4 hours. At the same time, without changing the technology / usually used to produce PAN-based HCs, it is possible to obtain HCs with a relatively high strength and elastic modulus. . ; .

The fibers obtained from the mixture are oxidized under tension at a temperature of 150-270 ° C in air for 2-4 hours, then carbonized at a temperature of at least 1100 ° C. Get HC with the following

150-170 kg / mm2 and elastic modulus 25000 kg / mm2.

.The fibers formed by the Limer (PAN) are heat-treated under conditions that have a higher, lower density of 1.61 g / cm3, and a module strength of 4000 kg / mm2.

Example 1. A fiber of cm rilonitrile and butadiene nitrile (95: 5 May.%) Is oxidized to Pakoaka in air at a temperature of 150-270 ° С for 4 h. The resulting fiber of argon carboeca at a temperature of 1100 5 min. Shrinkage of the fiber composition The resulting carbon wave strength is 170 ks / mm and the module is 21000 kg / mm

EXAMPLE 2. A fiber of cmrilnitrile and butadiene nitrile oxidizes the procedure for 2–3 hours. Half-fiber on graphite rods and argon carbon at 1100 ° С for 10 m fiber has a strength of 1

properties: density 1.7 g / cm, strength modulus 24000 kg / mm

150-170 kg / mm2 and elastic modulus 21000--25000 kg / mm2.

.Fibers formed from a homopolymer (PAN), heat-treated under the same conditions, have lower indicators: density 1.61 g / cm3, strength 70 kg / mm2, module 4000 kg / mm2.

Example 1. A fiber made of a mixture of polyacrylonitrile and butadiene nitrile rubber (95: 5 May.%) Is oxidized on a rigid pacoak in air at a temperature of 150-270 ° C for 4 hours.i.-g The resulting fiber is carbonized in then J ke argon at a temperature of 1100 ° C for about 5 minutes. Fiber shrinkage is 6-8%. The resulting carbon fiber has a strength of 170 ks / mm and an elastic modulus of 21000 kg / mm .1

EXAMPLE 2 A fiber made from a mixture of polyacrylryl nitrile and butadiene nitrile rubber oxidizes the procedure of Example 1 for 2–3 hours. A half-fiber is wound on graphite rods and carbonized in an argon stream at 1100 ° C for 10 minutes. Carbon fiber has a strength of 150 kg / mm2 and

PRI me R 3. Polyacrylonitrile fiber is treated according to the method of example 1. Receive carbon fibers with a strength of BO kg / mm2 and an elastic modulus of 14000 kg / mm2 /

PRI me R 4 (comparative). The fiber from polyacrylonitrile is treated according to the method of example 2, Receive brittle carbon fibers, the strength and elastic modulus of which is almost impossible to determine:: -: -: ...: - ::.

Claims (1)

Formula of the invention A method of obtaining high strength and high modulus carbon fibers by oxidation and carbonization of the starting fibers based on polyacrylonitrile, which consists in the fact that, in order to significantly reduce the duration of the process, fibers from mixtures of polyacrylonitrile and butadiene rubber.