The Study Of Magnesium Ethoxide-Based Catalyst For Propylene Gas Phase Polymerization

The preparation of the catalyst for propylene gas phase polymerization using the Mg(OEt)2as precursor of the carrier has been studied, the main contents include three parts.The first part is the synthesis of the Mg(OEt)2precursor by magnesium powder reacting with ethanol, it is the emphasis and difficulty in the paper. We synthesized the Mg(OEt)2through magnesium powder reacting with ethanol, the particle size and bulk density of the Mg(OEt)2is adjustable within the scope of20-60μm and0.20-0.30g/cm, then we prepared the target Mg(OEt)2with particle size of36.88μm, bulk density of0.25g/cm3, uniform particle size distribution, good particle shape, no fine powder and large particle according to the specific requirements of the catalyst for propylene gas phase polymerization. We determined the main reaction parameters such as the time interval between the first batch and the second batch, the stirring speed, the molar ration between the ethanol and magnesium in the first batch, initiator, which have significant effect on the performance of the Mg(OEt)2-We also established the process of the Mg(OEt)2growth based on the particle size distribution in the different reaction time.The second part is the determination of catalyst preparation technology and the preparation of the new type of catalyst component using the Mg(OEt)2as the carrier precursor. We determined the main technical parameters such as the initial reaction temperature, time rising rate, the join condition of internal donor, TiCl4load processing times, which have significant impact on the performance of the catalyst component; We prepared the new type of the catalyst component using the succinate compounds as internal donor and using the Mg(OEt)2as precursor of the carrier based on the optimized technical parameters, the biggest characteristic of the catalyst component is polymer with good particle shape, broad molecular weight distribution and high isotacticity.We researched the polymerization temperature, polymerization time and the hydrogen partial pressure on the performance of catalyst component, we also observed the particle shape of the Mg(OEt)2particle and catalyst particle, the "copy phenomenon" between the Mg(OEt)2precursor, the catalyst and the polymer is obvious, both of them showed good ellipsoid particles.