【作者】 豆秀丽；

【导师】 黄启谷；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2011， 硕士

【摘要】 采用邻苯二甲醛(酮)与氨基取代苯酚反应得到配体Ll-L4,然后与过渡金属卤化物反应,即得到非茂催化剂Cat.1-Cat.12。采用1H NMR,元素分析等手段对配体L1-L4的微观结构进行了表征。采用非茂催化剂(Cat.1-Cat.12)与MAO组成催化体系,催化乙烯聚合及乙烯/丙烯腈共聚合。探讨了催化剂结构及金属中心原子、聚合温度、A1/M摩尔比、催化剂浓度对乙烯聚合及乙烯/丙烯腈共聚合的影响。采用WAXD, DSC,13C NMR, FT-IR及GPC等手段对聚乙烯及乙烯/丙烯腈共聚物的结构和性能进行了表征。本文主要做了三方面的工作,即非茂催化剂(Cat.1-Cat.12)的合成,乙烯聚合[由(Cat.1-Cat.12)/MAO催化聚合]及乙烯/丙烯腈共聚合[由(Cat.4-Cat.12)/MAO催化聚合]。首先,采用邻苯二甲醛(酮)与氨基取代苯酚(2-氨基-4-甲基苯酚,2-氨基-5-甲基苯酚,2-氨基-4-叔丁基苯酚)反应得到四种化合物,即配体L1-L4,然后与过渡金属卤化物(TiCl4, ZrCl4, YCl3)反应,得到一系列新型苯氧基亚胺非茂催化剂Cat.1-Cat.12。其次,采用催化剂(Cat.1-Cat.12)/MAO催化乙烯聚合。结果发现催化剂结构、金属中心原子及反应条件对催化剂的催化活性影响较大,其中催化剂Cat.10的催化活性(2.93×106g PE/mol.Y.h)最大,分子量大,分子量分布窄(MW=3.35×105 g/mol, MWD=1.84)。此外,催化剂的催化活性在40-60℃范围内随温度的升高先上升后下降,在50℃达到最大值；随A1/M摩尔比及催化剂浓度的增加先上升后下降,在n(Al)/n(M)=300及催化剂浓度为1.0×104mol/L时达到最大值。聚合物的FT-IR,13C NMR结果表明所得聚乙烯为线型结构。第三,采用催化剂(Cat.4-Cat.12)/MAO催化乙烯/丙烯腈进行共聚合。结果发现以前过渡金属Ti为活性中心的催化剂Cat.6的催化活性最好,为1.77×104g P/mol.Ti.h,且具有较强的耐杂原子能力。WAXD, DSC表明共聚物中丙烯腈的插入量随着反应体系中丙烯腈浓度的增加而增加,丙烯腈的插入在一定程度上破坏了聚乙烯链的规整性,使其结晶度降低,熔点降低；13C NMR, FT-IR结果表明共聚物中丙烯腈摩尔浓度可达2.29%,共聚单体丙烯腈在大分子链中呈无规分布,不存在长序列结构单元,有利于共聚物性能的均匀化；GPC结果表明共聚物的重均分子量可达36500 g/mol,分子量分布小于2,呈单一分布。更多还原

【Abstract】 Phthaldialdehyde (ketone) was treated with substituted phenol to obtain ligands(L1-L4) which were then treated with transition metal halide, and obtained a series of novel non-metallocene catalysts(Cat.1-Cat.12). The structures of the ligands(L1-L4) were characterized by 1H-NMR and Elemental Analysis. These catalysts(Cat.1-Cat.12) were used to promote ethylene polymerization and ethylene/acrylonitrile copolymerization. The effects of the ligand structures and the metal center atoms(Ti, Zr) of these catalysts, polymetization temperature, Al/M molar ratio and concentration of catalyst on polymerization performance were investigated in detail. The structures and properties of polyethylene and ethylene/acrylonitrile copolymer obtained were characterized by WAXD, DSC,13C NMR, FT-IR and GPC. The main work in this thesis is composed of non-metallocene catalysts(Cat.1-Cat.12) synthesis, ethylene polymerization catalyzed by catalysts(Cat.1-Cat.12)/MAO and ethylene/acrylontrile copolymerization catalyzed by catalysts(Cat.4-Cat.12)/MAO. Firstly, Phthaldialdehyde(ketone) was treated with substituted phenol (2-amino-4-methylphenol,2-amino-5-methylphenol,2-amino-4-tert-butyl-Phenol) to obtain a series of ligands(L1-L4) which were then treated with transition metal halide(TiCl4, ZrCl4, YCl3), so that the novel non-metallocene catalysts(Cat.1-Cat.12) with phenoxy-imine ligands were obtained.Secondly, the catalysts(Cat.1-Cat.12)/MAO were employed in study on ethylene polymerization. The results indicated that the catalytic activity was greatly affected by the structures, metal center atoms of catalysts and reaction conditions. Besides, the catalytic activity of the catalyst(Cat.10) is the highest, up to 2.93×106 g PE/mol.Y.h, and the weight-average molecular weight of the polyethylene obtained was relative high, and its molecular weight distribution narrow(Mw=3.35×105 g/mol, MWD=1.84). It was also found that the catalytic activity of catalysts increased with enhancing temperature in the range of 40-60℃, peaking at 50℃. It also at first increased with the increasing of Al/M molar ratio and catalysts concentration and then decreaced, reaching the maximum value when Al/M molar ratio was 300, catalysts concentration 1.0×10-4mol/L. The results of 13C NMR and WAXD confirmed the linear structure of polyethylene obtained.Thirdly, ethylene/acrylonitrile copolymerization was catalyzed by the catalysts(Cat.4-Cat.12)/MAO. It was found that the catalyst(Cat.6) with early transition metal Ti as active centre had the strong capability of resistance to hetero atoms, so its catalytic activity was up to 1.77×104 g P/mol.Ti.h. WAXD, DSC results indicated that acrylonitrile incorporation content in copolymer increased with increasing of the acrylonitrile concentration of reaction system. The stereoregularity of polyethylene chain was demaged to some extent by the introduction of acrylonitrile unit, so the crystallinity, melting point(Tm) of copolymer were decreased.13C NMR and FT-IR results revealed that acrylonitrile content in molar of copolymer was up to 2.29%, acrylontrile unit was isolated in the copolymer chain homogeneously and there was no long sequence units which were good for performance homogenization of the whole copolymer molecular chain. GPC results showed that the Mw of copolymer was as high as 36500 g/mol, MWD less than 2, showing a single distribution.更多还原