负载型钛系催化剂合成高反1,4—聚异戊二烯的研究

Study on Synthesis of Trans 1,4—Polyisoprene with Supported Titanium Catalyst

以负载型钛为主催化剂(Ti),三异丁基铝(Al)为助催化剂,引发异戊二烯(Ip)均聚合,获得了高反1,4—聚异戊烯。聚合收率随单体浓度加大、聚合温度上升、聚合时间延长而提高,在Al/Ti≥50,Ti/Ip=3.5×10^(-4)(均mol/mol),30℃下聚合5小时,催化效率可达2000gPIp/gTi以上,PIp特性粘数在3—6dl/g范围。经IR和^(13)C-NMR联合测定表明,聚合物几乎完全为反1,4—链节,DSC测定其熔融温度在59.5—61.5℃之间。

The highly pure trans 1,4—polyisoprene was synthesized by polymerization of isoprene with supported titanium and triisobutylaluminium catalyst system. The efficiency of the catalysts increased when monomerconcentration, polymerization temperature and time were increased. Under suitable conditions the catalytic efficiency could exceed 2000g PI_P/g Ti, the inherent viscosity of the polymer was about 3 -6dl/g. The chain structure of the synthesized PIp was characterised by IR-and-^(13)C-NMR technique, it was comfirmed that all the PIp was almost of trans 1, 4—structure. Its melt temperature was about 59.5—61.5℃ by DSC determination.