A micro-reaction system and method for preparing p-/meta-aramid fibers

Abstract

The invention relates to a micro-reaction system and a micro-reaction method for preparing para / meta-aramid. The micro-reaction system is composed of a micro-reactor and a stirring kettle, wherein the micro-reactor is internally provided with a microstructure distribution plate or a micro-channel; and sieve pores or through grooves are formed in the microstructure distribution plate. The method comprises the steps of dissolving p / m-phenylenediamine into a calcium chloride solution, and adding pyridine to obtain a reaction solution A; dissolving isophthaloyl dichloride / paraphthaloyl chloride into the calcium chloride solution to obtain a reaction solution B; mixing the reaction solutions A and B in the micro-reactor, and triggering condensation polymerization reaction to obtain a reaction solution C; enabling the reaction solution C to enter the stirring kettle, and reacting under stirring to produce a product D; and washing the product D to obtain para / meta-aramid. The material mixing effect is enhanced through the micro-reactor, so that reaction heat can be rapidly removed, and the process stability is improved; and due to the further reaction in the stirring kettle, the polymerization degree is further increased, the pressure drop in the reaction process is reduced, and the safety is improved.

Description

technical field [0001] The invention belongs to the technical field of fiber preparation, and relates to a micro-reaction system and method for preparing p- / meta-aramid fibers. Background technique [0002] The scientific name of p- / meta-aramid fiber is poly p- / isophthalamide p- / m-phenylenediamine. Both fiber materials have excellent properties such as high strength, high modulus, high temperature resistance, acid and alkali resistance, and light weight. . In particular, the ultra-high strength and other excellent properties of para-aramid fiber make it widely used in the fields of spacecraft, rocket structural materials, bulletproof materials, rubber reinforcement materials, building structure reinforcement materials and asbestos replacement materials. Para-aramid, carbon fiber, and ultra-high molecular polyethylene fiber are collectively referred to as the three major high-performance fibers in the world today. At present, the para-aramid market is mainly monopolized by ...

AI Technical Summary

Problems solved by technology

This method needs to keep the temperature of the reaction system near 0°C, but the viscosity of the system is high, which makes it very difficult to transfer heat; at the same time, the polymerization product generated in the twin-screw reactor has local inhomogeneity, which affects the subsequent dissolution spinning process

Due to the complexity of the system in the process of preparing para / meta-aramid fibers, the heat transfer and mixing problems of the low-temperature solution polycondensation method make the preparation process poorly controllable, and the properties of the obtained products are not repeatable.

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