Synthesis Of High Cis And Narrow Distribution Polybutadiene Rubber Based On Neodymium Neodecanoate Catalyst System

The high-cis and narrow distribution(Dp=Mw/Mn?3)polybutadiene rubber is superior to the traditional wide-distribution butadiene rubber in elasticity and wear resistance,which helps to improve fuel efficiency,reduce fuel consumption and save tire loss.In this paper,neodymium neodecanoate catalytic system was used to investigate the influence of various components of catalyst on the polymerization of butadiene under the condition of vial experiment,and the ratio of the vial experiment was applied on the batch reactor.The narrow-distributed butadiene rubber with Mooney viscosity of 45.3,54.0,66.3 obtained by polymerization and a broad-distributed sample were processed respectively to compare their differences in properties.Under the conditions of vial polymerization,it was found that reducing the amount of neodymium neodecanoate,Cl,HAl and Al and increasing the amount of the fourth component can lower the Dp,increasing the amount of Cl added and reducing the amount of HAl and Al added can improve the cis-1,4 structural content.The polybutadiene rubber obtained by polymerization has a conversion rate of 90.1 %,a cis-1,4 structure content of 98.3 %,and Dp=2.84,which has the characteristics of high cis and narrow distribution.Under the experiment of batch reactor amplification,it was found that cis-1,4 structure content decreased to 96.0 %,Dp became about 2.5,and the amount of neodymium neodecanoate was adjusted to synthesize polybutadiene rubber with Mooney viscosity between 43.8 and 66.8.The narrow-distributed polybutadiene rubber after mixing and processing is obviously superior to the broad-distribution sample in terms of tensile strength and aging performance,and the performance get better with the increase of Mooney viscosity,but the carbon black of the narrow-distribution polybutadiene rubber has poor dispersibility and processability and gradually deteriorates as the Mooney viscosity increases.Therefore,based on the excellent properties of the narrow distribution polybutadiene rubber in terms of mechanical properties,and the application of the narrow-distribution polybutadiene rubber to the tire processing process is important for improving the tire quality.