Wide-distribution polyisocyanate-coupled multi-arm star random butadiene-styrene copolymer and preparation method thereof

Abstract

The invention discloses a wide-distribution polyisocyanate-coupled multi-arm star random butadiene-styrene copolymer and a preparation method thereof. The preparation method comprises: mixing butadiene and / or isoprene with styrene, continuously adding into a solvent within 40-60 min, under the effect of a C2-6 alkyl ether of tetrahydrofurfuryl alcohol and butyllithium, performing polymerization at 45-75 DEG C, so as to obtain an active butadiene-styrene random copolymer; and performing coupling on the obtained butadiene-styrene random copolymer with a polyisocyanates prepolymer coupling agent at 50-75 DEG C, and after coupling is finished, terminating with water, so as to obtain the copolymer. The random butadiene-styrene copolymer has high molecular weight distribution, the middle ends have a relatively large number of polar groups, and the main chain has a high short-branched-chain content. When being matched and mixed with rare earth BR (rare earth-based cis-1,4-polybutadiene rubber) with high linearity and white black carbon, the random butadiene-styrene copolymer has extremely good compatibility with white carbon black, the mechanical properties and the wet skin resistance of the rubber material are both improved, dynamic heat build-up and rolling resistance are substantially reduced, and the random butadiene-styrene copolymer is a relatively ideal high-performance tyre surface rubber material. The simple rapid preparation method for the random butadiene-styrene copolymer is suitable for industrialized production.

Description

technical field [0001] The invention relates to a multi-arm star-shaped random styrene-butadiene copolymer coupled with wide-distribution polyisocyanate and a preparation method thereof, belonging to the field of synthesis of modified styrene-butadiene rubber. Background technique [0002] Styrene and conjugated diene can be directionally polymerized into a random copolymer under the trigger of butyllithium in a solvent. This material is especially suitable for making tires. As an ultra-high performance tire compound, SSBR with high vinyl content, high cis-butadiene rubber and white carbon black are its main components. However, due to the low Weissenbery effect and elastic memory effect of general-purpose SSBR, during the mixing process of high-cis-rare-earth polybutadiene rubber and white carbon black with high molecular chain regularity and high cold flow in the internal mixer, the rubber The shear force of the material in the mixing process is insufficient, the friction...

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Problems solved by technology

[0006] The present invention aims at the narrow molecular weight distribution of solution-polymerized styrene-butadiene rubber in the prior art, the elastic memory of the raw rubber is not high, and the Weissenbery effect is also low, and the high-cis-rare-earth polymer with high molecular chain regularity and large cold fluidity Butadiene rubber and white carbon black have low frictional heat generation during the mixing process in the internal mixer, white carbon black cannot be effectively melted in the rubber compound, and the rubber compound cannot be matured and formed; the purpose is to provide a high molecular weight distribution , a multi-arm star-shaped random styrene-butadiene copolymer with more polar groups at the middle end and a high content of short branched chains on the main chain. This copolymer is mixed with rare earth BR and white carbon black with high linearity. It has good compatibility with silica, the mechanical properties and wet skid resistance of the compound are improved, and the dynamic heat generation and rolling resistance are greatly reduced. It is an ideal high-performance tire compound

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