A kind of liquid polyconjugated diene rubber and preparation method thereof

Abstract

The present invention relates to the field of liquid poly conjugated diene rubbers, and discloses a liquid poly conjugated diene rubber preparation method, which comprises: (1) in the presence of an organic lithium compound and a non-polar solvent, carrying out an initiation reaction on conjugated diene for 1-8 min; (2) in the presence of a blocking agent, carrying out a first polymerization reaction on the product of the initiation reaction until the conversion rate of the conjugated diene is more than 70 wt%; and (3) in the presence of an accelerating agent, carrying out a second polymerization reaction on the product of the first polymerization reaction. The invention further provides the liquid poly conjugated diene rubber prepared through the preparation method. According to the present invention, with the preparation method, the performing of the polymerization reaction can be well controlled, such that the liquid poly conjugated diene rubber with characteristics of narrow molecular weight distribution and highly-controlled molecular weight can be prepared through the high monomer conversion rate; and especially the method can be performed in the high monomer concentration, and has the good industrial application value.

Description

technical field [0001] The present invention relates to liquid polyconjugated diene rubber, in particular, to a liquid polyconjugated diene rubber and a preparation method thereof. Background technique [0002] Liquid rubber is generally a viscous flowable rubber with an index average molecular weight of 500-60000. It has the advantages of simple processing equipment and easy operation. It can be used to prepare various rubber products such as tapes, hoses, and shock pads. Liquid rubber is also an excellent processing aid and has a wide range of uses in the plastics and electronics industries. According to different polymerized monomers, common liquid rubbers are polybutadiene rubber, polyisoprene rubber, styrene-butadiene copolymer, nitrile rubber and neoprene rubber. [0003] Liquid rubber polymerization methods mainly include free radical polymerization and anionic polymerization. At present, the free radical polymerization method is mainly used to produce liquid rubber...

AI Technical Summary

Problems solved by technology

At present, free radical polymerization is mainly used in China to produce liquid rubber. Its advantage is low cost, and its disadvantages are poor linearity of molecular chains, easy branching, wide molecular weight distribution, and difficulty in microstructure adjustment.

[0004] The liquid polybutadiene rubber obtained by anionic polymerization has a narrow molecular weight distribution, the microstructure and molecular weight distribution can be adjusted freely, and the quality is uniform, but there are also significant shortcomings: the anionic polymerization rate is extremely fast, and the polymerization heat is difficult to withdraw in time; low molecular weight and At high monomer concentration, the conversion of the monomer is completed in a short time, the temperature of the polymerization system is as high as 300-400°C, the side reaction is very serious, and the product performance deteriorates

Due to the use of retarded anionic polymerization technology, the concentration of polymerized monomers has been greatly increased and the production efficiency has been improved, but there are disadvantages that the viscosity of the system increases sharply in the later stage and the reaction rate decreases sharply.