高流动线型低密度聚乙烯的工业化生产

Industrial production of linear low density polyethylene with high fluidity

在Unipol气相法工艺聚乙烯装置上,通过合理控制反应系统的表观气速、反应温度、乙烯分压、反应器床层料位等工艺参数,有效控制了线型低密度聚乙烯(LLDPE)粉料的细粉含量,解决了因循环压缩机干气密封堵塞引起的装置无法长周期运行的问题,实现了稳定生产高熔体流动速率(21.0 g/10 min)、密度为0.924 g/cm3的LLDPE产品。所产LLDPE的拉伸屈服应力达9.61 MPa,常温简支梁缺口冲击强度达67 kJ/m2。产品各项性能均达到用户要求,可替代进口同类产品,得到用户认可并在多领域得到应用。

Fine powder percentage of linear low density polyethylene （LLDPE） was controlled effectively by reasonably regulating process parameters, such as specific gas velocity in the reaction system, reaction tem- perature, ethylene partial pressure, bed level height, etc. on a Unipol gas-phase process polyethylene plant. Con- sequently, the problem that long period operation could not be achieved due to dry gas seal failure of circulating compressor was solved, and the LLDPE product obtained had consistent high melt flow rate of 21.0 g/10 rain, density of 0.924 g/era3, tensile stress at yield of 9.61 MPa, and notched Charpy impact strength at room tempera- ture of 67 kJ/m2. The properties of the LLDPE product could meet the requirements of downstream users, and the LLDPE product could replace the same kinds of imported products and had been applied in many fields with fa- vorable feedback from the clients.