Synthesis and properties of neodymium butadiene rubber and its vulcanizates

The neodymium butadiene rubber (Nd-BR) has been recognized for its particularly suitable use in tread and sidewall of green tires. The homogeneous neodymium-based catalyst systems containing neodymium carboxylate, alkyl aluminium compound and chlorinating agent were successfully developed for the coordination polymerizations of butadiene in our laboratory. The catalyst possessed high catalytic activity to butadiene polymerization in hexane and exhibited high stereo-selectivity to butadiene polymerization in hexane and polybutadienes with extremely high cis-1,4 configuration could be produced under appropriate reaction conditions. Stereo-specificity is a key factor for the performance of Nd-BR product. Nd-BR with high cis-1,4 content behaved low Payne effect and good processing properties, which is mainly attributed to the strong interaction between polymer and filler. Nd-BR vulcanizates with higher cis-1,4 content possess the superior mechanical properties and dynamic mechanical properties, such as modulus at 300%, tensile strength, abrasion resistance, heat build-up, compression properties and rolling resistance and wet-skid resistance. Long chain branched Nd-BR possesses an improved cold flow resistance, processing performance and mixing performance with the filler. The excellent properties of these high cis-1,4 Nd-BR products lead to their especially suitable application in green-tyre components.
The neodymium butadiene rubber (Nd-BR) has been recognized for its particularly suitable use in tread and sidewall of green tires. The homogeneous neodymium-based catalyst systems containing neodymium carboxylate, alkyl aluminium compound and chlorinating agent were successfully developed for the coordination polymerizations of butadiene in our laboratory. The catalyst possessed high catalytic activity to butadiene polymerization in hexane and exhibited high stereo-selectivity to butadiene polymerization in hexane and polybutadienes with extremely high cis-1,4 configuration could be produced under appropriate reaction conditions. Stereo-specificity is a key factor for the performance of Nd-BR product. Nd-BR with high cis-1,4 content behaved low Payne effect and good processing properties, which is mainly attributed to the strong interaction between polymer and filler. Nd-BR vulcanizates with higher cis-1,4 content possess the superior mechanical properties and dynamic mechanical properties, such as modulus at 300%, tensile strength, abrasion resistance, heat build-up, compression properties and rolling resistance and wet-skid resistance. Long chain branched Nd-BR possesses an improved cold flow resistance, processing performance and mixing performance with the filler. The excellent properties of these high cis-1,4 Nd-BR products lead to their especially suitable application in green-tyre components.