Preparation method of long-chain branched cis-rich polybutadiene

Abstract

The invention relates to a preparation method of long-chain branched cis-rich polybutadiene. The preparation method specifically comprises the following step of: reacting linear or linear short-chain branched cis-rich polybutadiene with a bifunctional or polyfunctional organic compound in the presence of a radical initiator, so that long-chain branched cis-rich polybutadiene is prepared. Compared with linear or linear short-chain branched cis-rich polybutadiene, the thermal stability, cold flow resistance, and mixing uniformity with packing, and the like, of the long-chain branched cis-rich polybutadiene are obviously improved, and the physical and mechanical properties and dynamic mechanical properties of vulcanized rubber are also obviously improved.

Description

Technical field: [0001] The invention relates to a preparation method of long-chain branched high-cis-polybutadiene, specifically, in the presence of a free radical initiator, linear or linear short-chain branched high-cis-polybutadiene is combined with a bifunctional group or Multifunctional organic compounds are reacted to prepare long chain branched high cis polybutadiene. Background technique: [0002] The rolling resistance, wet skid resistance and wear resistance of tires are important indicators for evaluating tire performance. Only tires that achieve "triangular balance" can achieve the best energy-saving effect. High-cis polybutadiene rubber has a series of advantages such as good elasticity, good wear resistance, good low-temperature performance, low heat generation, and low rolling resistance. It is the second largest synthetic rubber variety and is widely used in tire manufacturing, but usually high The cis-polybutadiene has a linear structure or a linear short-...

AI Technical Summary

Problems solved by technology

[0003] At present, there are three methods for preparing branched polybutadiene rubber: (1) Direct polymerization method: Copolymerize butadiene with low molecular weight polybutadiene macromonomer to prepare polybutadiene grafted with short chain branches , but due to the short polybutadiene branch chain, the cold flow resistance and physical and mechanical properties of polybutadiene rubber have not been effectively improved, see Polymer Science, Ser.B, 2006, 48, 61-65; patent WO2009121516A1 Discloses a method by adjusting the polymerization temperature and H in the catalytic system 2 The O / Nd molar ratio is a method for directly preparing branched polybutadiene, but this method has strict requirements on the polymerization temperature and the preparation of the catalyst, and the branched structure of the prepared branched polybutadiene is difficult to control; (2) the chain end Coupling reaction: the active chain end of linear polybutadiene and organic halides, organometallic compounds, carboxylic acids, quinone compounds, thiazole compounds, dithiocarbamate, thioimide, sulfenamide , amine compounds containing epoxy groups, aldehydes or thioaldehydes containing amino groups, partially epoxidized or anhydride-functionalized unsaturated natural oils and other multifunctional compounds for end-group coupling reactions to prepare star-branched Polybutadiene, but these multifunctional compounds usually need to be added when the polymerization reaction active chain exists, the coupling efficiency is relatively low, and there are relatively many short-chain branched products, see EP0863165A1, EP1026181A1, EP1099711A2 and EP1650227A2; (3) Intermolecular coupling Method: Add compounds such as dichlorodisulfide, sulfur dichloride or thionyl chloride to the polybutadiene solution with a linear structure for double bond addition reaction, and form a branched structure through sulfur chemical bonds to improve the cold resistance of raw rubber. Flow properties, but prone to partial cross-linking reaction, see US5567784