Method for preparing strong acidic ion-exchange fibers

Abstract

The invention provides a method for preparing strong acidic ion-exchange fibers. The method comprises the steps of performing vacuum packaging for polyolefine fibers; pre-irradiating through a radiation source; feeding pre-irradiated polyolefine fibers into a grafting solution under the protection of inert gas to react to obtain a polyolefine fiber grafting copolymer; then sulphonating through chlorosulfonic acid to obtain strong acidic ion-exchange fibers; a cross-linking agent is fed into the grafting solution to enable high mechanical strength and relatively high exchange capacity of the sulphonated fibers. According to the method, the process is simple, the polyolefine fiber grafting copolymer is easily prepared under a low temperature condition; the prepared polyolefine fiber-styrene copolymer is low in styrene autopolymer (less than 2%); the dichloroethane solution of chlorosulfonic acid is treated as a sulphonating agent, so that little chlorosulfonic acid is used, and the post-processing is simple.

Description

Technical field [0001] The invention belongs to the application field of nuclear technology, and relates to a method for preparing strongly acidic ion exchange fibers, especially for preparing copolymers of polyolefin fibers and styrene in a low-temperature environment. Background technique [0002] The graft polymerization of polyolefin fibers can adopt methods such as chemical grafting, radiation grafting and plasma grafting. Chemical grafting usually requires the addition of an initiator. It is difficult to form a uniform initiation point during the reaction, which easily triggers the explosion of olefin monomers, which increases the difficulty of removing comonomers in subsequent processes. Moreover, the strength of the grafted fibers is low, making it difficult to Satisfies the requirements of use; irradiation grafting, especially γ-rays with strong penetrating power, can uniformly form free radicals in larger volume fibers, so that the grafting reaction is uniform on t...

AI Technical Summary

Problems solved by technology

The co-irradiation grafting operation process is simple, but due to the unfavorable factors of styrene self-polymerization, it is difficult to clean after grafting, and the strength of the obtained fibers decreases significantly, resulting in a serious decline in product quality

At the same time, in the industrial production of strong acid ion exchange fibers prepared by co-irradiation, the change of ambient temperature has a great influence on the process of co-irradiation grafting, which makes the grafting rate change greatly, especially in the northern regions where the winter temperature is low When the co-irradiation grafting reaction cannot even proceed

At present, the use of concentrated sulfuric acid and oleum as vulcanizing agents to prepare strongly acidic ion-exchange fibers still dominates. When using concentrated sulfuric acid as a sulfonating agent, an excess of 3-4 times is usually required, and even the reaction liquid uses concentrated sulfuric acid. The water will dilute the concentration of concentrated sulfuric acid, so that the reaction time is prolonged, or the reaction temperature is increased, and sometimes it is necessary to gradually increase the temperature. After the reaction is completed, a complex process of gradient dilute acid washing and filtration is required.