一种用Ziegler-Natta催化剂直接合成支化型高熔体强度聚丙烯的新策略

A New Strategy to Prepare High-Melt-Strength Polypropylene with Branched Structure Using Ziegler-Natta Catalyst

利用以9,9-双(甲氧基甲基)芴(BMMF)为内给电子体的Ziegler-Natta催化剂,通过在本体聚合中非同步引入具有支化/交联作用的α,ω-双烯烃,直接合成了具有长链支化结构的高熔体强度聚丙烯(HMS-PP)。用SEM、DSC、GPC和动态流变测试等方法分析了所得聚合物的结构、性能及动态流变行为。实验结果表明,MgCl2/TiCl4/BMMF催化体系可通过引入1,9-癸二烯直接合成具有支化结构的HMS-PP。引入1,9-癸二烯对聚合活性及聚合物的熔点、熔融焓、相对分子质量及其分布等无显著影响。MgCl2/TiCl4/BMMF催化体系具有较高的共聚能力,所得共聚物具有较高的熔体强度和熔体黏度、较低的玻璃化转变温度。

High-melt-strength polypropylene（HMS-PP） with long-chain branched structure was synthesized through bulk polymerization,in which an α,ω-diene was introduced nonsynchronously,using a Ziegler-Natta catalyst with 9,9-bis（methoxymethyl） fluorene（BMMF） as an internal electron donor.The structure,properties and dynamic rheological behaviors of the synthesized polymer were characterized by means of SEM,DSC,GPC and dynamic rheology measurement.The results indicated that the branched HMS-PP could be synthesized by using the MgCl2/TiCl4/BMMF catalyst.The effects of the introduction of 1,9-decadiene on the catalyst activity and the melting point,melting enthalpy and relative molecular mass of the polymer were little.The copolymerization performance of the MgCl2/TiCl4/BMMF catalyst was good and the prepared polymer had high melt strength and viscosity,and low glass transition temperature.