A method for modifying nylon fibers under tension in supercritical CO2

Abstract

The invention relates to a method for modifying a nylon fiber under the tension action in supercritical CO2 and in particular relates to a method for carrying out grafting reaction on the surface and interior of the nylon fiber and a solvent in the supercritical CO2 under the action of certain extra tension. The method for modifying the nylon fiber under the tension action in the supercritical CO2 mainly comprises the following steps: setting a certain temperature, a certain pressure and certain tension, taking a grafting solvent into the surface and interior of the nylon fiber by virtue of infiltration, swelling and carrying effects of the supercritical CO2, and carrying out chain extension bridging and a grafting reaction on the grafting solvent as well as an amide NH bond, -COOH, -NH2 and the like of the nylon fiber under the action of a certain stretching force at a certain temperature and a certain pressure. The method for modifying the nylon fiber under the tension action in the supercritical CO2 guarantees that the fiber is in a stretched state in a reaction process, so that orientation degree and crystallinity of a molecular chain are increased while grafting degree of the surface and interior of the nylon fiber is increased, crystal particles are enlarged, crystals are more and more complete, and enhancement of fiber strength and modulus of the nylon fiber can be facilitated, so that crosslinking of a polar amorphous region is enhanced, and the method for modifying the nylon fiber under the tension action in the supercritical CO2 is significant in modification on polar polymer fibers.

Description

Technical field [0001] The invention belongs to the field of fiber modification and relates to a supercritical CO 2 A method of modifying nylon fibers under moderate tension. Background technique [0002] Nylon fiber has excellent mechanical and electrical properties, and also has the advantages of wear resistance, oil resistance, self-lubrication, corrosion resistance and good processing performance. However, PA has high water absorption, poor low temperature and dry impact toughness, and poor dimensional stability. Its application range is subject to certain restrictions. In order to meet the special requirements of different fields, PA needs to be modified, especially how to obtain reinforced and toughened modified materials that integrate high rigidity, high strength and high toughness, which is a hot research topic. [0003] For example, the Chinese Patent Bulletin discloses a patent application with the application number: CN201210326753.2, titled a nylon 6 modified material...

AI Technical Summary

Problems solved by technology

This method does not have any effect of tension, the effect of surface treatment is limited, and the effect of stretching and orientation to enhance fiber strength cannot be achieved

[0007] There are many methods for grafting aramid fibers in the prior art, but most of them have the disadvantages of troublesome operation and low efficiency.