Abstract

Thermal, mechanical, and viscoelastic properties of polybutadiene-based rubber materials are highly dependent on polybutadiene microstructure. The use of polar modifier in association with alkyllithium is a well-known method to obtain polybutadiene with a high vinyl content. Another approach is to use bimetallic initiating species such as alkyllithium combined to heavier alkali metal alkoxide (RONa, ROK…). The polymerization control is nevertheless not achieved and several parameters were found to influence it. Using bimetallic initiating systems based on alkyllithium and a potassium alkoxide, alkyllithium structure, initiator preformation time, and initiator composition were identified as parameters influencing the anionic polymerization process of butadiene and/or polybutadiene microstructure. In addition, the use of trimetallic systems based on alkyllithium, potassium alkoxide, and alkylaluminum was investigated in order to prevent side reactions regardless of the [K]/[Li] ratio and of the initiator preformation time.

中文翻译：

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锂/钾多金属体系对丁二烯的阴离子聚合：对聚合控制和聚丁二烯微观结构的影响

摘要

聚丁二烯基橡胶材料的热，机械和粘弹性能高度依赖于聚丁二烯的微观结构。与烷基锂结合使用极性改性剂是获得具有高乙烯基含量的聚丁二烯的公知方法。另一种方法是使用双金属引发剂，例如烷基锂结合成更重的碱金属醇盐（RONa，ROK…）。然而，仍未实现聚合控制，并且发现几个参数对其影响。使用基于烷基锂和烷氧基钾的双金属引发体系，烷基锂的结构，引发剂的形成时间和引发剂的组成被确定为影响丁二烯和/或聚丁二烯微结构阴离子聚合过程的参数。此外，