Preparation method of polyurethane modified aramid fiber pulp

Abstract

The invention discloses a preparation method of polyurethane modified aramid fiber pulp. A polyurethane spinning solution is added to an aramid fiber spinning solution, and the obtained mixed spinning solution is spun. Polyurethane has a high elasticity and a high strength, so the modified aramid fiber pulp has enough strength and toughness; and spinning fibers are treated with an aqueous LiCl solution, and the treated spinning fibers are complexed with carbonyl groups in the molecular chain of aramid fibers in order to destroy the regularity of the molecular chain of the aramid fibers and etch the surface of the aramid fibers, so the surface roughness of the aramid fibers is increased, the specific surface area of the modified aramid fiber pulp obtained after beating treatment is increased, and the adsorption capability to resin and rubber materials is improved.

Description

technical field [0001] The invention relates to the preparation of aramid pulp, in particular to a preparation method of polyurethane modified aramid pulp. Background technique [0002] Brake linings use frictional resistance to achieve their braking effect. They are not only used in transportation tools such as airplanes, trains and automobiles, but also widely used in tractors and tricycles. The quality, variety and quantity of brake linings directly affect the performance of machinery, and then affect the development of the machinery industry. The reinforcing fiber is the "skeleton" of the brake material, which not only requires high tensile strength and good reinforcement effect, but also has strict requirements on the ease of operation of the process and the compatibility between the fiber and the matrix material. In addition, the material should also have Environmental protection, sufficient resources and affordable prices. [0003] Aramid is a new type of high-tech ...

AI Technical Summary

Problems solved by technology

[0004] However, in the molecular chain of aramid fiber, the amide group is located between two benzene rings, forming a large π-bond conjugated structure with the benzene ring, which has high internal rotation hindrance, and the surface of aramid fiber is smooth and has low chemical activity. 1. The rubber material has poor adsorption capacity, so its interface adhesion with the resin and other fibers in the friction material formula is not strong, and it is easy to fall off from the matrix material when it is subjected to external force, resulting in poor long-term performance of the friction material