五甲基茂基三(对氯苯氧基)钛/甲基铝氧烷体系催化丙烯聚合反应与动力学的研究  

STUDY ON KINETICS OF PROPYLENE POLYMERIZATION WITH A η5-PENTAMETHYLCYCLOPENTADIENYLTRI-p- CHLOROPHYNOXYTITANIUM/METHYLALUMINOXANE SYSTEM

作　　者：曾勇军[1] 祝方明[1] 林尚安[1] 

机构地区：[1]中山大学化学与化学工程学院高分子研究所,广州510275

出　　处：《高分子学报》2006年第3期397-401,共5页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号20174050)资助项目

摘　　要：采用茂钛配合物五甲基茂基三(对氯苯氧基)钛[Cp- Ti(O- C6H4Cl -P)3]甲基铝氧烷(MAO)体系进行丙烯聚合反应,考察了聚合温度和Al- Ti摩尔比(nAl- nTi)对聚合活性和产物分子量的影响.研究发现在合适的聚合条件下,聚合初期产物的分子量随聚合时间线性增大,并保持较窄的分子量分布(Mw Mn=1.5～1.8),表现出准活性聚合的行为,而聚合物的GPC曲线呈双峰分布,表明聚合初期的体系存在多活性中心.另外,初步提出了衰减动力学方程以探讨聚合速率衰减期的丙烯聚合反应规律,求出了不同条件下丙烯聚合的衰减系数,从而可计算出衰减期内任一时间的丙烯聚合速率.A titanocene complex of η^5-pentamethyleyclopentadienyltri-p-chlorophynoxy-titanium [ Cp^＊Ti（O-C6 H4-Cl-P）3 ] was used in combination with methylaluminoxane （MAO） as cocatalyst to catalyze propylene polymerization. The effects of polymerization conditions such as temperature and Al/Ti molar ratio （nAl/nTi） on catalytic activity and molecular weight of polypropylene obtained were investigated. It was found that under the given polymerization conditions the molecular weight of polypropylene increased as the polymerization proceeded at the early stage,and the molecular weight distribution remained narrow （Mw/Mn = 1.5 - 1.8）, which displayed the behavior of quasi-living polymerization; while the bimodal GPC profiles indicated a multi-site system at the early stage. In addition, a kinetics equation was presented to study propylene polymerizations at the depressing stage of polymerization rate, and the depressing coefficients under various conditions were obtained. With the depressing coefficient, the polymerization rate could be estimated at any time of the depressing stage.

关 键 词：茂钛配合物 甲基铝氧烷 聚合反应动力学 衰减系数 

分 类 号：O631[理学—高分子化学]