Conjugated diene and monovinylarene random copolymer, and preparation method thereof

Abstract

The invention relates to the field of conjugated diene and monovinylarene random copolymers, and discloses a conjugated diene and monovinylarene random copolymer, and a preparation method thereof. Themethod is the continuous polymerization reaction conducted in each reactor, and includes the following steps that under the condition of anionic polymerization, reaction materials containing the first part of conjugated diene, monovinylarene, solvents, gel inhibitors and single organic lithium initiators are continuously introduced from the bottoms of reactors, the second part of conjugated dieneis introduced in the middles of the reactors, the third part of conjugated diene is continuously introduced on the upper parts of the reactors, and the polymerization temperature is controlled to be90-140 DEG C. According to the preparation method, under the conditions that any structural regulators or random agents are not added, the reaction temperature is high, and residence time is reasonable, the conjugated diene and monovinylarene random copolymer can be prepared with controllable basic molecular weight and low vinyl content.

Description

technical field [0001] The present invention relates to the field of random copolymers of conjugated dienes and monovinylarenes, in particular to a method for preparing random copolymers of conjugated dienes and monovinylarenes and the random copolymer prepared by the method things. Background technique [0002] As a styrene-butadiene copolymer of general-purpose rubber, the styrene structural units on the molecular chain of solution-polymerized styrene-butadiene rubber require an ideal random distribution as much as possible. The presence of styrene blocks will change the dynamic mechanical properties of rubber. When the molecular chain of solution polystyrene-butadiene rubber contains a small amount of styrene blocks, it can cause van der Waals force between the end of the flexible butadiene molecular chain and the styrene block. , thereby increasing the tensile strength. The existence of a large number of styrene blocks will seriously damage the elasticity, strength and...

AI Technical Summary

Problems solved by technology

The random agent can make the vinyl content of the polymer between 10-20% by weight, but the synthesis process of this regulator is complicated and the production cost is high

[0007] Although the use of the above structural regulators or randomizers can effectively inhibit the formation of styrene blocks in styrene-butadiene copolymers, it also has certain limitations: one is to increase the production cost; the other is that some randomizers need It can only be applied after dissolving in polar solvents, but toluene is highly toxic and pollutes the environment; third, structural regulators such as amines will have residues in the product, which does not meet environmental protection requirements; fourth, some structural regulators are reacting The solubility in the system is poor, the repeatability is poor, and the source of raw materials is not smooth; the fourth is that the addition of a structure regulator will lead to an increase in the vinyl structure content of the solution-polymerized styrene-butadiene rubber, and it is impossible to achieve low-vinyl solution-polymerized styrene-butadiene rubber copolymerization preparation

Without the addition of structure regulators and randomizers, at a reaction temperature of 70-100°C, the conversion of butadiene and styrene monomers at the outlet of the second kettle is not complete, which limits its industrial application

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