Star-shaped high-styrene rubber and preparation method thereof

Abstract

The invention provides an isoprene-styrene-butadiene high-styrene rubber containing random gradual transition segments and a preparation method thereof. The structural formula is [I1→S1-I2 / S2-B3]n-Y, wherein Y is Si or Sn, n is the degree of branching, and n is greater than or equal to 2.5 and less than or equal to 4. I1→S1 is polystyrene and polyisoprene gradient copolymer; I2 / S2 is polystyrene and isoprene random segment copolymer; B3 is butadiene homopolymer; polystyrene in the structural formula The mass fraction of the gradient segment of polyisoprene and polyisoprene is 30-70wt%, the mass fraction of the random segment of polystyrene and polyisoprene is 25-60wt%, and the mass fraction of butadiene homopolymer is 5-10 %; The high styrene rubber of the present invention has the characteristics of high hardness, good strength, good elasticity, and high degree of branching. When used in combination with various synthetic rubbers or natural rubbers, it can improve the rigidity, hardness, and wear resistance of rubber products , tear resistance, dielectric properties and other properties.

Description

technical field [0001] The present invention relates to a kind of isoprene-styrene-butadiene high styrene rubber containing random gradient segment and its preparation method. The synthesized polymer is characterized by high hardness, high wear resistance, good elasticity and branching High-strength star-shaped high-styrene rubber. Background technique [0002] The copolymer composed of isoprene or butadiene and styrene, the bound styrene is generally 23-30%, if the bound styrene content is high, the plasticity of the obtained copolymer is greater; otherwise, the elasticity of the copolymer is greater . Generally, copolymers with a styrene binding amount of 45% to 70% in the molecular structure are called high-styrene rubbers, and those with a combined styrene content of more than 70% are called high-styrene resins. Due to the high amount of bound styrene in high styrene rubber, its physical properties are different from those of general-purpose styrene-butadiene rubber. ...

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Problems solved by technology

And mostly adopt latex coagulation technology in the prior art, although this technological process can obtain the high styrene rubber with better performance, the main problem that this method exists is: at first in technology, need to synthesize SBR-1500 or SBR-1500 respectively earlier SBR-1502 latex and high styrene resin emulsion, the two emulsions that pass the analysis are mixed in a certain proportion, and then coagulated and dried to obtain high styrene rubber. The process is relatively long and requires two water phases, oil phases, Initiator preparation and degassing and other synthesis processes; secondly, in terms of production costs, since the conversion rate of synthetic SBR-1500 or SBR-1502 latex monomers is only 70%, unreacted monomers account for 30%, and this part of monomers is in small and medium-sized It is difficult to recycle in large-scale production devices, resulting in high production costs and relatively large equipment, auxiliary materials, personnel, time, and energy required for the polymerization process; in addition, in the production cycle, since the synthesis temperature of high styrene resin emulsion is High-temperature polymerization, there are many structural gels in the polymerization kettle, and the polymerization kettle used usually needs to be cleaned once to produce 10 batches, so the utilization rate of the equipment is low

The above-mentioned polymers all have the disadvantages that the tensile strength and hardness of the product are not high enough

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