Preparation method of double functionality lithium system initiator

Abstract

In the mixed solvent using non-polar solvent as main component the metal lithium and alpha-methylstyrene or isoprene are reacted to directly prepare bifunctionality anionic oligomer. Its mixed solvent uses arene or paraffine or their mixture as main component, contains ether or amine or both mixture, in which arene and paraffine content is 50-99.9% (valoume) and ether and amine content is 0.1-50%(valume), the conjugated arene and metal lithium are reacted for 1-6 hr. under the condition of -50- -50 deg.C to obtain reactino product, said product is filtered to obtain bifunctionality initiator.

Description

Technical field: [0001] The invention relates to a preparation method of an initiator for synthesizing polymers by anion method. Especially for the preparation of bifunctional lithium initiators for the synthesis of block copolymers or telechelic polymers. Background technique: [0002] Alkali metals and fused-ring aromatics can form homogeneous complexes in ether solvents. The complexes are highly active and can react with dienes or styrene monomers to generate difunctional anion initiators. However, the complexes The formation reaction speed and maximum concentration of methionine increase according to the polarity of the solvent, so polar ether molecules such as tetrahydrofuran (THF) and dimethoxyethane (DMF) must be used as solvents for preparation and storage. The existence of a large number of polar molecules will have the following negative effects: 1. The side group content of the conjugated diene polymer is too large, the glass transition temperature will increase,...

AI Technical Summary

Problems solved by technology

The existence of a large number of polar molecules will have the following negative effects: 1. The side group content of the conjugated diene polymer is too large, the glass transition temperature will increase, and the performance requirements of rubber will not be met.

2. Polar solvents are more expensive, resulting in an increase in the cost of the initiator

3. The initiator is unstable and has negative reactions

Although this method excludes polycyclic aromatic hydrocarbon compounds, the complicated distillation process has become an obstacle to its practical application.