针对烯烃气相聚合过程在线控制困难的问题,设计了一套新型的带有在线检测和控制的烯烃多段聚合反应装置.该装置不仅具有普通的温度和压力控制功能,还采用了自创的气相组成和尾气流量在线检测与控制新技术——差压式流量控制器(VFC)与热式流量控制器(MFC)联合检测技术.利用该装置进行了聚丙烯/乙丙橡胶两相合金的合成研究.结果表明,新型装置技术的响应时间很短,使得气相共聚反应过程的控制更加灵敏和精确,不仅有效地控制了反应器内的气相组成,而且可同时获得气相共聚阶段的各单体瞬时聚合速率,以及共聚物的瞬时组成等重要的动力学参数,从而为深入研究气相共聚动力学和高性能聚烯烃合金的制备奠定了基础.
A novel laboratory reactor system for the multistage polymerization of olefin has been developed, in which a new on-line monitoring system consisting of a differential pressure volumetric flow meter, a thermal mass flow meter and control valves was adopted to detect and control monomer compositions in the gas phase with a delay time of 0.01-3 s. With this apparatus, PP/EPR alloy was synthesized and kinetics for the second stage, the gas-phase copolymerization process was studied. The results indicated that the composition for the binary gas-phase copolymerization of olefin could be sensitively and precisely controlled with the aid of the new control system. Meanwhile, instantaneous reaction rate of monomers, and the instantaneous copolymer composition, were on-line measured and controlled. It has been demonstrated that this reactor system is a useful platform for studies of gas-phase olefin copolymerization process and preparation of high performance polyolefin alloy.