丙烯聚合催化剂内给电子体的研究

对丙烯聚合Ziegler-Natta催化剂中内给电子体的研究进展情况进行了综述,同时分析了单酯类、双酯类、二醚类、二酮类和二醇酯类化合物作为内给电子体的催化剂特性。     

丙烯聚合催化剂内给电子体的研究进展

对丙烯聚合Ziegler-Nalta催化剂中内给电子体的研究进展情况进行了综述,同时分析了单酯类、双酯类、二醚类、二酮类和二醇醋类化合物作为内给电子体的催化剂特性。     

外给电子体在催化丙烯聚合中的作用研究

在丙烯聚合过程中加入外给电子体，对于提高齐格勒-纳塔催化剂活性及控制聚合物立构规整性方面发挥着极为重要的作用，寻找新型给电子体一直是齐格勒-纳塔催化剂的研究热点。综述了近年来国内外新型外给电子体的研究进展，同时分析了芳香族羧酸酯类、有机胺类、有机硅氧烷类和杯芳烃类化合物作为外给电子体的催化剂特性。最后，对该领域的发展作了展望。     

丙烯聚合用齐格勒-纳塔催化剂的作用机理

讨论了丙烯聚合用齐格勒-纳塔催化剂的作用机理，以及反应体系内的氯化镁、内给电子体、烷基铝、硅烷和氢气等对丙烯聚合的影响。     

丙烯聚合用Ziegler-Natta催化剂的内给电子体研究进展

综述了丙烯聚合用Ziegler-Natta(Z-N)催化剂中内给电子体的研究进展,并对各类内给电子体的应用实例进行了评价。其中,以1,3-二醚、琥珀酸酯和1,3-二醇酯类化合物为内给电子体制备的Z-N催化剂具有活性高、立体定向性高,用该催化剂制备的聚丙烯具有特征相对分子质量分布等特点。分析具有代表性的内给电子体所制催化剂的活性中心模型发现,单酯体系的等规和无规活性中心在Lewis酸作用下存在可逆平衡,二醚体系中醚氧原子电子云的转移和二醚的空间结构影响钛活性中心的性能。     

中国专利

<正> 齐格勒-纳塔型固体催化组分和催化体系、制备方法及其在1-烯烃聚合中的应用本发明涉及新的固体催化组分,该组分可以与助催化剂铝化合物、任选地作为另外的助催化剂的外给电子体组合使用以形成齐格勒-纳塔催化剂体系。该固体催化体系含有钛或钒化合物、至少1种卤素的镁化合物、颗粒状多孔载体和任选的内给电     

内给电子体在气相聚乙烯催化剂中作用的研究

采用浸渍法制备工艺,在MgCl2/SiO2复合载体齐格勒-纳塔(Z-N)催化剂制备过程中加入了醇、酯、醚和硅烷四类内给电子体,考察了不同内给电子体对气相聚乙烯催化剂的活性、产物堆密度、细粉含量的影响;结果表明:正硅酸乙酯作为聚乙烯催化剂的内给电子体效果较好,催化剂活性达到3447.5g·PE/g·Cat·h,聚合物堆密度达到0.33g·cm-3,细粉含量仅占0.052%,电子显微镜下催化剂颗粒呈均匀的球形。     

Z-N催化剂内给电子体作用机理的研究进展

综述了内给电子体对齐格勒-纳塔丙烯聚合催化剂作用机理的研究进展。从内给电子体在催化剂体系中的作用方式及机理、内给电子体的种类与催化剂性能的关系以及内给电子体的结构与催化剂性能的关系三方面．讨论了内给电子体对催化剂活性中心的区域选择性和立体选择性的影响。内给电子体的引入影响了催化剂的活性、氢调敏感性和产物的相对分子质量及其分布。     

高纯聚丙烯树脂的研究进展

介绍了聚丙烯(PP)树脂中灰分的组成,并分析了影响PP树脂中灰分含量的主要因素。从催化剂和聚合工艺两方面综述了世界上各大公司开发的直接在反应器内制备高纯PP的技术进展,并详细分析了各技术的优缺点及工业化前景。目前,各大公司生产高纯PP主要采用Ziegler-Natta催化剂,内给电子体包括多元羧酸酯类、琥珀酸酯类、醚类、二醇酯类以及含有可取代的亚苯基芳香族二酯类化合物,聚合工艺包括气相工艺、液相工艺以及超临界技术,且大多对助催化剂(即有机铝化合物)的用量进行了严格限定。     

给电子体在烯烃聚合过程中的作用

齐格勒-纳塔催化剂是烯烃聚合时最常用的催化剂.在不同的给电子体的用量、聚合温度等条件下,考察给电子体对烯烃聚合的影响.通过室内环道评价装置和红外光谱仪测定聚合物,确定给电子体对烯烃聚合的作用.实验表明,在助催化剂:1.5mL,主催化剂:0.01 mL,给电子体MgCl02:0.39 g,反应温度:0℃,二段聚合温度:-...     

二醚化合物在Ziegler-Natta催化剂中的应用及其合成研究

综述了二醚化合物作为给电子体在Ziegler-Natta催化剂中的应用，简要介绍了二醚化合物的合成方法。     

Synthesis and characterization of some long-chain diesters with branched or bulky moieties

Several novel fatty diesters with bulky moieties were synthesized by esterification of mono- or bifunctional fatty acids or with mono- or bifunctional alcohols using p-toluenesulfonic acid as catalyst. They were characterized by ¹H and ¹³C nuclear magnetic resonance as well as positive chemical ionization (PCl) mass spectrometry. The PCl mass spectra of the resulting diol diesters and diacid diesters are discussed and compared. The compounds were investigated as potential additives for improving the cold flow properties of vegetable oil esters used as biodiesel. Retired.     

The structural constituents of carnauba wax

Type 1 yellow carnauba wax has been separated into its structural constituents. Analyses of these constituents by a variety of conventional techniques has shown the composition to be: hydrocarbon 0.3–1%, aliphatic esters 38–40%, monohydric alcohols 10–12%, ω-hydroxy aliphatic esters 12–14%,p-methoxycinnamie aliphatic diesters 5–7%,p-hydroxycinnamic aliphatic diesters 20–23%, an uncombined triterpene type diol 0.4% and uncombined acids and other unknown constituents 5–7%. Type 4 carnauba wax, the common wax of commerce, was found to be essentially the same as Type 1, with the exception that for Type 4, the cinnamic esters were highly polymerized and none of the uncombined triterpene diol could be isolated. Presented at the AOCS Meeting, New Orleans, April 1970.     

Skin surface lipids of the dog

The skin surface lipid of the dog has been reported to contain a high proportion of diol diesters having a lower mobility on thin layer chromatography than diesters from other species in spite of containing similar fatty acid and diol components. In the present study, dog skin surface lipid was separated by preparative thin layer chromatography into sterol esters (42%), wax diesters (32%), free sterols (9%), polar lipids (7%), and unidentified components (10%). The diesters contained 1,2-diols, each esterified with one long chain fatty acid and one isovaleric acid moiety. The diols were principally branched chain C₂₁ and C₂₂ compounds while the long chain fatty acids esterified with them were mainly C₂₀ and C₂₁ branched compounds. The fatty acids from the sterol esters were mostly saturated, branched chain C₁₉ to C₂₃, together with 7% of straight chain monoenoic acids, principally C₂₁ and C₂₂. There were only trace amounts of free sterols other than cholesterol, while the esterified sterols contained 96% cholesterol and 4% lathosterol.     

丙烯聚合Ziegler-Natta催化剂中给电子体的作用

本文从内给电子体的作用、外给电子体的作用、内外给电子体的协同作用等方面综述了给电子体化合物在丙烯聚合Ziegler—Natta催化剂中的作用。     

Über die Synthese einiger Hydroxyalkylglyceryldiäther und deren Diester aus hydriertem Cardanol

Synthesis of Some Hydroxyalkyl Glyceryl Diethers and Their Diesters from Hydrogenated Cardanol A few hydroxyalkyl glyceryl diethers and their diesters could be synthesized by the reaction of sodium salt of hydrogenated cardanol with various hydroxyalkyl chlorohydrinethers, the latter being prepared by reacting epichlorohydrin with the corresponding glycols.