Anion slurry polymerization method for preparing caprolactam homopolymer and copolymer

Abstract

The invention relates to a method for preparing aminocaprolactam homopolymer and copolymer. It takes aminocaprolactam as monomer, takes aliphatic hydrocarbon as dispersing agent, takes alkali or base metal as catalyst, takes acyl chloride, format agent or isocyanate as catalyst promoter to carry out slurry polymerization process for anion and copolymerization with polyether, and gets powder nylon6 homopolymer and copolymer low-melting point thermosol at low temperature below 160 Deg. C and in a short time. The invention is characterized in that it possesses feature of easy controllable stability for molecular weight and liner molecular construction, it is easy to ass residual catalyst deactivator to make product possess good property for spinning and second-time shaping at the end of reaction or after reaction.

Description

field of invention The present invention relates to a method for preparing caprolactam homopolymer and copolymer by anionic slurry polymerization technique, the obtained caprolactam homopolymer and copolymer and the use thereof. Background of the invention At present, the synthesis of polycaprolactam (nylon 6) mainly includes the hydrolytic ring-opening polymerization technology of caprolactam and the anionic polymerization technology represented by monomer casting (MC nylon) and reactive extrusion (RIM). The hydrolysis ring-opening technology uses caprolactam as the monomer and a small amount of water as the ring-opening agent to carry out the polymerization reaction in the VK polymerization tube at 250-280°C for 20-28 hours. The reaction temperature is relatively high and the time is relatively long. Since this technology is an equilibrium reversible reaction, the product always contains 3-10% monomers and oligomers, so hot water extraction is required, which further incr...

AI Technical Summary

Problems solved by technology

At present, the anionic polymerization of caprolactam developed at home and abroad mainly includes monomer casting nylon (MC nylon) and reactive extrusion (RIM) technology, but the mature monomer casting technology (MC nylon) is only suitable for processing large castings and other materials, and cannot Formed into conventional thermoplastic resin chips for flexible processing, inflexible applications

Reactive extrusion (RIM) technology is a technology that tries to combine the advantages of low temperature and high speed of anionic polymerization with the flexible processing advantages of thermoplastic chips. However, this method has two shortcomings: first, because the anionic polymerization reaction is very violent, the reaction The molecular weight of the product is difficult to control stably; secondly, because the reaction is an active polymerization, after the reaction is terminated, the active center still remains in the product slice, and when the secondary forming process is heated, the active center will cause the molecules to produce branched chains and crosslinks, which will not Facilitate normal processing

The reactive extrusion method has no effective active center passivation measures, which limits the secondary forming process of making slices

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