CAJ | 학술논문

用复合载体负载钒化合物，同时加入邻苯二甲酸二丁酯，制得钒系聚乙烯催化剂，并通过淤浆聚合得到聚乙烯。用GPC和13C NMR等方法研究H2对催化剂聚合活性及聚乙烯性能的影响。实验结果表明，催化剂的活性中心分两类：一类受H2影响较大，一类受H2影响很小；H2是有效的链转移剂。随加氢量的增大，聚合活性逐渐降低，当H2分压为0.08 MPa时，聚合活性衰减趋于平稳。聚合物的表观密度随加氢量的增大呈先升高后降低的趋势。不加氢时聚合物粒径分布相对较分散，而加氢后聚合物粒径分布较集中。随加氢量的增大，聚合物的熔体流动速率增大、相对分子质量减小、相对分子质量分布也逐渐变宽、聚合物的甲基支化度逐渐增大，有利于提高聚合物的加工性能。
용복합재체부재범화합물，동시가입린분이갑산이정지，제득범계취을희최화제，병통과어장취합득도취을희。용GPC화13C NMR등방법연구H2대최화제취합활성급취을희성능적영향。실험결과표명，최화제적활성중심분량류：일류수H2영향교대，일류수H2영향흔소；H2시유효적련전이제。수가경량적증대，취합활성축점강저，당H2분압위0.08 MPa시，취합활성쇠감추우평은。취합물적표관밀도수가경량적증대정선승고후강저적추세。불가경시취합물립경분포상대교분산，이가경후취합물립경분포교집중。수가경량적증대，취합물적용체류동속솔증대、상대분자질량감소、상대분자질량분포야축점변관、취합물적갑기지화도축점증대，유리우제고취합물적가공성능。
A vanadium-based catalyst was prepared by immobilization of a vanadium compound onto a novel composite support and addition of dibutyl phthalate,and then was used in the slurry polymerization of ethylene with triisobutylaluminium as the co-catalyst. The effects of hydrogen on the properties of both the catalyst and the polyethylene products were investigated by means of GPC and 13C NMR. The results showed that:there were two kinds of active centers in the catalyst:one was affected evidently by hydrogen and another was affected a little;and hydrogen was an effective chain transferer. The catalyst activities decreased gradually with increasing the hydrogen amount,and at the partial pressure of hydrogen of 0.08 MPa,the activities tend to smooth and steady. With increasing the partial pressure of hydrogen,the bulk density of the polymer increased firstly and then decreased,the molecular weight distribution widened,and the particle size distribution became relatively concentrated. Besides,the degree of methyl branching of the polyethylene produced with the catalyst system increased with the addition of hydrogen,which was beneficial to processing the polymer products.