财政支持由美国明尼苏达大学（启动资金）和ACS石油研究基金（54225-DNI3）提供。设备采购的化学系核磁共振设备通过来自美国国立卫生研究院（S10OD011952）的资助来自美国明尼苏达大学配套资金的支持。我们承认明尼苏达核磁共振中心为高温NMR。资助核磁共振仪器由副总统办公室的研究，医学院，生物科学，美国国立卫生研究院，美国国家科学基金会的学院和明尼苏达州医学基金会提供的。我们感谢约翰·沃尔泽（埃克森美孚）为PEEK高通量的搅拌桨的礼物。

注意:使用前请咨询所有相关的材料安全数据表（MSDS）。几个在这些合成中使用的化学物质是剧毒和致癌性，而几个是引火并点燃在空气中。执行这些反应包括利用工程控制（通风橱，手套箱）和个人防护装备时，请使用所有适当的安全措施（安全眼镜，手套，实验室外套，全长长裤，闭趾鞋）。下面的过程部分涉及标准的无空气的处理技术。 1.制备[双（2,6-二甲基苯基）-2,3- butanediimine]的NIBR 2，21-25 <ol><li>双（2,6-二甲基苯基）-2,3- butanediimine:（α-二亚胺） <ol><li>溶解2,3​​-丁二酮（1.0毫升，11毫摩尔）和2,6-二甲基苯胺（2.8毫升，23毫摩尔）于20毫升甲醇中的100ml圆底烧瓶中。 </li><li>添加甲酸（0.4毫升，11毫摩尔），搅拌反应一吨室温直到二亚胺沉淀（通常为1-2小时，但可放置过夜）。如果沉淀不形成，集中使用旋转蒸发器和冷却在冰浴中，将反应混合物。 </li><li>过滤用玻璃料和过滤烧瓶中的反应混合物和洗涤黄色固体用20ml冷甲醇和干燥，真空浓缩。 注:1 H NMR（500兆赫，CD 2 Cl 2中）:δ7.06（D，J = 7.6Hz赫兹，4H），6.92（吨，J = 7.5Hz赫兹，2H），2.00-1.99（米，19H）。 </li></ol></li><li>的（1,2-二甲氧基乙烷）NIBR 2制备 :DME-NIBR 2 <ol><li>在氮气气氛下，在2-颈圆底烧瓶装有回流冷凝器和橡胶结合无水溴化镍（NIBR 2,15克，0.069摩尔），原甲酸三乙酯（30毫升，0.185摩尔）和甲醇（100ml）隔膜上在氮气气氛下在Schlenk线。 </li><li>在氮气氛下回流棕色反应混合物，直到绿色解决方案的形式。这通常需要2-3小时，但该反应可留在必要回流过夜。 </li><li>使混合物冷却后，集中使用上的Schlenk线真空泵以形成暗绿色凝胶的反应混合物中。 </li><li>插管转移过量1,2-二甲氧基乙烷（DME，100毫升）中上果岭凝胶，它立即形成橙色固体。一旦所有的DME加入，加热在85℃下反应另外的2小时，直到浅橙色反应混合物的形式。将反应冷却到室温，此时的光橙色固体沉淀物。 </li><li>从反应烧瓶中取出回流冷凝器和替换的Schlenk玻璃料在氮气气氛下连接到第二个Schlenk接收瓶。 180°使橙色反应混合物进入的Schlenk玻璃料和过滤反应混合物旋转整个装置。 </li><li>取出原有的反应瓶中，放在隔膜的舒伦克星期五吨。套管传送的DME（100ml）中，然后戊烷（100毫升）洗DME-NIBR 2。干燥固体橙色真空带入手套箱。 注意:DME-NIBR 2可以无限期地在室温下在氮气氛下被存储。当敞开于大气中，它形成了一个绿，水合凝胶。 </li></ol></li><li> （〔α二亚胺] NIBR 2）:[双（2,6-二甲基苯基）-2,3- butanediimine] NIBR 2的制备<ol><li>在手套箱，结合DME-NIBR 2（1.0克，3.2毫摩尔）和双（2,6-二甲基苯基）-2,3- butanediimine（1.1克，3.8毫摩尔）在50毫升圆底烧瓶中。 </li><li>加入20ml二氯甲烷，搅拌过夜，在室温下进行。 </li><li>过滤用玻璃料和过滤烧瓶内的反应混合物中。 在真空下洗涤棕色固体用75毫升二氯甲烷和干燥。 注意:此镍催化剂可以无限期储存在惰性气氛手套箱中在室温下。它是人大多数溶剂使不溶性的，并没有进行这样的标准刻画。 </li></ol></li></ol> 2.催化制备储备液<ol><li>储备溶液-的〔〔α二亚胺]的Ni（CH 3）] + [MAO制备<ol><li>通过加入0.0041克〔α二亚胺] NIBR 2（8.0×10 -6摩尔）到小瓶用7.5毫升甲苯制备一1.0×10 -3 M的催化剂储备溶液。 </li><li>向搅拌的镍悬浮液，在甲苯添加0.50 ml的30％甲基铝氧烷（MAO）的搅拌1分钟。颜色会从一个棕色悬浮液变为蓝绿色溶液。这种溶液可以储存在-30℃达6小时，并在随后的聚合反应中使用。 注:甲基铝氧烷是自燃的，并会在空气中吸烟。它应该只在惰性气氛手套箱中使用和护理应该从手套箱中除去污染的注射器/玻璃器皿时服用。典型地，一个注射器第二玻璃器皿都用甲苯洗涤，在手套箱，并放置在一个金属罐，从的Kimwipes或任何其他易燃物质分离。被污染的甲苯被盖住在小瓶中，并从与金属罐手套箱取出。这些项目被转移到通风橱那里打开到空气和使其缓慢猝灭防护玻璃的后面。 </li></ol></li><li>的ZnEt 2原液制备<ol><li>通过1.75毫升的甲苯溶解0.25毫升ZnEt 2准备1.2M的解决方案。 注:二乙基锌是自燃的，并会在空气中点燃。它应该只在惰性气氛手套箱中使用和护理应该从手套箱中除去污染的注射器/玻璃器皿时服用。典型地，注射器和玻璃器皿都用甲苯洗涤，在手套箱，并放置在一个金属罐，从的Kimwipes或任何其他易燃物质分离。被污染的甲苯被盖住在小瓶中，并从与金属罐手套箱取出。帖Ë项目被转移到它们打开到空气的通风柜并使其缓慢猝灭防护玻璃的后面。 </li></ol></li></ol> 3.催化聚合中使用并行高压反应器<ol><li>压力范围<ol><li>设置在平行压力反应器中的所有的聚合反应顶置搅拌容纳在N 2气氛手套箱。编程在软件中聚合:表示总反应体积（3.0毫升）中，所述吹扫气体（N 2），所需的反应气体（乙烯），期望的压力（15-150 psi）的，和所需的反应时间（1小时）。 注:Biotage柱奋进并行高压反应器与能够监视气体吸收用于聚合的一个单独的计算机。所有聚合反应进行至少三次，以确保准确性和再现性。使用这种类型的反应器中的几个变量的可在单次实验中或在多个exp的过程来调节eriments包括:将反应气体，压力，温度，时间，溶剂，体积，催化剂，或链转移试剂。通过执行8反应在具有实时气体摄取时间，催化反应被有效地检测。在这种情况下，反应小瓶有5毫升的最大体积，因此，3毫升的体积被选择占聚合物的形成。另外，标准浓度，压力和时间是根据文献的条件。21，这些聚合反应可在单个反应器中的压力或甚至在Schlenk线上的所有来完成，但它是更难以实现更高的压力或气体吸收的反应。 </li><li>将玻璃衬反应小瓶到8口井。使用深度工具，以确保玻璃衬里在适当的高度。将叶片叶轮进入塔顶组装。 </li><li> 根据表1填充反应小瓶: <table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td> 反应釜 </td><td> 压力（psi） </td><td> 催化剂卷。 （毫升） </td><td> ZnEt 2卷。 （毫升） </td><td> 甲苯卷。 （毫升） </td></tr><tr><td> 1 </td><td> 15 </td><td> 0 </td><td> 0 </td><td> 3 </td></tr><tr><td> 2 </td><td> 15 </td><td> 0.1 </td><td> 0 </td><td> 2.9 </td></tr><tr><td> 3 </td><td>三十</td><td> 0 </td><td> 0 </td><td> 3 </td></tr><tr><td> 4 </td><td>三十</td><td> 0.1 </td><td> 0 </td><td> 2.9 </td></tr><tr><td>五</td><td> 60 </td><td> 0 </td><td> 0 </td><td> 3 </td></tr><tr><td> 6 </td><td> 60 </td><td> 0.1 </td><td> 0 </td><td> 2.9 </td></tr><tr><td> 7 </td><td> 150 </td><td> 0 </td><td> 0 </td><td> 3 </td></tr><tr><td> 8 </TD&gt; <td> 150 </td><td> 0.1 </td><td> 0 </td><td> 2.9 </td></tr></tbody></table> 表1中。反应条件为，压力范 ​​围的反应。 </li><li>保证O形环在金属槽正确就位并小心地将顶部搅拌装配在基座上，并以交替方式拧紧。确保所有的螺丝是否拧紧，然后按开始在软件中。 监测经过气体吸收测量反应。 </li><li> 1小时聚合后，从手套箱中取出反应小瓶中并沉淀聚乙烯与在甲醇中加入5％盐酸，除去溶剂并真空干燥。质量的聚合物，以获得产率和在反应过程中进行比较的乙烯消耗。 </li><li>计算催化剂，它是每摩尔催化剂形成的聚合物的质量，每小时聚合的活性。 </li><li>分析分子量和分散度指数干燥聚乙烯采用高温凝胶渗透色谱法（GPC）。溶解0.002克的聚合物在2毫升1,2,4-三氯苯在135℃。根据制造商的协议运行GPC中。 注意:使用Agilent PL-GPC 220高温GPC / SEC系统被用于在135℃和使用聚苯乙烯标准来分析聚合物的分子量数据为适合。 </li><li>分析支化度时，分支型，并使用高温。13 C NMR干燥聚乙烯的末端基团类型。溶解0.050-0.080克聚合物在0.5ml四氯乙烷-D 2（C 2 D 2氯4）在130℃。运行在600MHz的NMR样品在130℃下至少2000扫描。分支根据文献分配聚合物26-28 注意:安捷伦/瓦里安600MHz的光谱仪上在130℃下用于13 C NMR分析。 </li></ol></li><li>链转移聚合<ol><li>按照相同的程序，并分析作为第3.1节，填充在反应器和编程根据表 2中的参数的软件: <table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td> 反应釜 </td><td> 压力（psi） </td><td> 催化剂卷。 （毫升） </td><td> ZnEt 2卷。 （毫升） </td><td> 甲苯卷。 （毫升） </td></tr><tr><td> 1 </td><td> 60 </td><td> 0.1 </td><td> 0 </td><td> 2.9 </td></tr><tr><td> 2 </td><td> 60 </td><td> 0.1 </td><td> 0.005 </td><td> 2.9 </td></tr><tr><td> 3 </td><td> 60 </td><td> 0.1 </td><td> 0.01 </td><td> 2.89 </td></tr><tr><td> 4 </td><td> 60 </td><td> 0.1 </td><td> 0.015 </td><td> 2.89 </td></tr><tr><td>五</td><td> 60 </td><td> 0.1 </td><td>0.025 </td><td> 2.88 </td></tr><tr><td> 6 </td><td> 60 </td><td> 0.1 </td><td> 0.042 </td><td> 2.86 </td></tr><tr><td> 7 </td><td> 60 </td><td> 0.1 </td><td> 0.06 </td><td> 2.84 </td></tr><tr><td> 8 </td><td> 60 </td><td> 0.1 </td><td> 0.085 </td><td> 2.82 </td></tr></tbody></table> 表2中。反应条件为链转移聚合反应。 </li><li>此外，计算链由于ZnEt 2的存在和每基于以下等式催化剂的摩尔发起链数延长的摩尔数。7 <img alt="式（1）" src="/files/ftp_upload/53212/53212eq1-2.jpg" width="250" /> （MR）扩展-链摩尔扩展由于ZnEt 2的存在下（摩尔） 产量聚合物 -聚合物的形成团块（G） Mn为-号AVER从GPC的聚合物的年龄分子量（克/摩尔） 链发起 -每摩尔催化剂发起链数 摩尔催化剂 -摩尔催化剂的聚合中使用</li><li>请启动对ZnEt 2的浓度数量链的情节。 </li></ol></li></ol>聚合反应4.动力学分析:链转移和传播率<ol><li>速率传输的（K P） <ol><li>每次运行在仅〔α二亚胺] NIBR 2存在时，使乙烯消耗量与时间的关系的曲线图。 </li><li>适合的初始乙烯气体吸收于线状区域，以获得起始速率。在图2a的情况下，该痕迹适合为500〜2000秒。 </li><li>使用斜坡的平均，得到传播（K p）的速率为在所需压力下的特定催化剂。 </li></ol></li><li>比率链转移（K P） <ol><li>通过找到气体的消耗在不包含催化剂的反应器的摩尔数判断乙烯的浓度，[C 2 =]，3.0 ml的从平均气体吸收（溶解度）甲苯。 </li><li>使1 / M n的梅奥图（从GPC求出的分子量数据）与[ZNR X] / [C 2 =]（从ZnEt 2的浓度置于反应器中）。7，29 </li><li>适合数据基于所述梅奥方程的直线。乘以28的斜率，乙烯的分子量，得到的链转移到传播速率（K E / K P＆）的速率之比。 <img alt="公式3" src="/files/ftp_upload/53212/53212eq3.jpg" width="230" /> MN -从GPC的聚合物的数均分子量与ZnEt 2 M NØ -数均从GPC的聚合物的分子量，而不ZnEt 2 K E特征-价格链转移的 K P＆ -传播率 [ZNR X] - ZnEt 2的浓度在反应 [C 2 =] -乙烯在反应浓度 28 - 乙烯的分子量</li><li>乘法K E特征 / K P＆由前一节中所得到的K p来得到的链转移K E特征的速率。 </li></ol></li></ol>

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F., Bujadoux, K., Mortreux, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Controlled+polyethylene+chain+growth+on+magnesium+catalyzed+by+lanthanidocene:+A+living+transfer+polymerization+for+the+synthesis+of+higher+dialkyl-magnesium.">Controlled polyethylene chain growth on magnesium catalyzed by lanthanidocene: A living transfer polymerization for the synthesis of higher dialkyl-magnesium.</a> Polymer. 48 (7), 1844-1856 (2007).</li><li>Busico, V., Cipullo, R., Chadwick, J. C., Modder, J. F., Sudmeijer, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+Regiochemical+and+Stereochemical+Errors+on+the+Course+of+Isotactic+Propene+Polyinsertion+Promoted+by+Homogeneous+Ziegler-Natta+Catalysts.">Effects of Regiochemical and Stereochemical Errors on the Course of Isotactic Propene Polyinsertion Promoted by Homogeneous Ziegler-Natta Catalysts.</a> Macromolecules. 27 (26), 7538-7543 (1994).</li><li>Annunziata, L., Duc, M., Carpentier, J. -. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chain+Growth+Polymerization+of+Isoprene+and+Stereoselective+Isoprene-Styrene+Copolymerization+Promoted+by+an+ansa-Bis(indenyl)allyl-Yttrium+Complex.">Chain Growth Polymerization of Isoprene and Stereoselective Isoprene-Styrene Copolymerization Promoted by an ansa-Bis(indenyl)allyl-Yttrium Complex.</a> Macromolecules. 44 (18), 7158-7166 (2011).</li><li>Kretschmer, W. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversible+Chain+Transfer+between+Organoyttrium+Cations+and+Aluminum:+Synthesis+of+Aluminum-Terminated+Polyethylene+with+Extremely+Narrow+Molecular-Weight+Distribution.">Reversible Chain Transfer between Organoyttrium Cations and Aluminum: Synthesis of Aluminum-Terminated Polyethylene with Extremely Narrow Molecular-Weight Distribution.</a> Chem. Eur. J. 12 (35), 8969-8978 (2006).</li><li>Britovsek, G. J. P., Cohen, S. A., Gibson, V. C., Maddox, P. J., van Meurs, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Iron-Catalyzed+Polyethylene+Chain+Growth+on+Zinc:+Linear+&#945;-Olefins+with+a+Poisson+Distribution.">Iron-Catalyzed Polyethylene Chain Growth on Zinc: Linear &#945;-Olefins with a Poisson Distribution.</a> Angew. Chem., Int. Ed. 41 (3), 489-491 (2002).</li><li>Xiao, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Novel+Linear-Hyperbranched+Multiblock+Polyethylene+Produced+from+Ethylene+Monomer+Alone+via+Chain+Walking+and+Chain+Shuttling+Polymerization.">A Novel Linear-Hyperbranched Multiblock Polyethylene Produced from Ethylene Monomer Alone via Chain Walking and Chain Shuttling Polymerization.</a> Macromolecules. 42 (6), 1834-1837 (2009).</li><li>Simon, L. C., Mauler, R. S., De Souza, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+the+alkylaluminum+cocatalyst+on+ethylene+polymerization+by+a+nickel-diimine+complex.">Effect of the alkylaluminum cocatalyst on ethylene polymerization by a nickel-diimine complex.</a> J. Polym. Sci. A Polym Chem. 37 (24), 4656-4663 (1999).</li><li>Hue, R. J., Cibuzar, M. P., Tonks, I. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+Polymeryl+Chain+Transfer+Between+Group+10+Metals+and+Main+Group+Alkyls+during+Ethylene+Polymerization.">Analysis of Polymeryl Chain Transfer Between Group 10 Metals and Main Group Alkyls during Ethylene Polymerization.</a> ACS Catalysis. 4 (11), 4223-4231 (2014).</li><li>Johnson, L. K., Killian, C. M., Brookhart, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+Pd(II)-+and+Ni(II)-Based+Catalysts+for+Polymerization+of+Ethylene+and+.alpha.-Olefins.">New Pd(II)- and Ni(II)-Based Catalysts for Polymerization of Ethylene and .alpha.-Olefins.</a> J. Am. Chem. Soc. 117 (23), 6414-6415 (1995).</li><li>Ittel, S. D., Johnson, L. K., Brookhart, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Late-Metal+Catalysts+for+Ethylene+Homo-+and+Copolymerization.">Late-Metal Catalysts for Ethylene Homo- and Copolymerization.</a> Chem. Rev. 100 (4), 1169-1204 (2000).</li><li>Bautista, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+Diels-Alder+Cycloadditions+of+exo-Imidazolidin-2-one+Dienes.">Synthesis and Diels-Alder Cycloadditions of exo-Imidazolidin-2-one Dienes.</a> J. Org. Chem. 76 (19), 7901-7911 (2011).</li><li>Rulke, R. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NMR+study+on+the+coordination+behavior+of+dissymmetric+terdentate+trinitrogen+ligands+on+methylpalladium(II)+compounds.">NMR study on the coordination behavior of dissymmetric terdentate trinitrogen ligands on methylpalladium(II) compounds.</a> Inorg. Chem. 32 (25), 5769-5778 (1993).</li><li>Ward, L. G. L., Pipal, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anhydrous+Nickel+(II)+Halides+and+their+Tetrakis+(Ethanol)+and+1,2-Dimethoxyethane+Complexes.">Anhydrous Nickel (II) Halides and their Tetrakis (Ethanol) and 1,2-Dimethoxyethane Complexes.</a> Inorg. Syntheses. 13, 154-164 (1972).</li><li>Galland, G. B., de Souza, R. F., Mauler, R. S., Nunes, F. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=13C+NMR+Determination+of+the+Composition+of+Linear+Low-Density+Polyethylene+Obtained+with+[&#951;3-Methallyl-nickel-diimine]PF6+Complex.">13C NMR Determination of the Composition of Linear Low-Density Polyethylene Obtained with [&#951;3-Methallyl-nickel-diimine]PF6 Complex.</a> Macromolecules. 32 (5), 1620-1625 (1999).</li><li>Cotts, P. M., Guan, Z., McCord, E., McLain, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+Branching+Topology+in+Polyethylenes+As+Revealed+by+Light+Scattering+and+13C+NMR.">Novel Branching Topology in Polyethylenes As Revealed by Light Scattering and 13C NMR.</a> Macromolecules. 33 (19), 6945-6952 (2000).</li><li>Wiedemann, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monofunctional+hyperbranched+ethylene+oligomers.">Monofunctional hyperbranched ethylene oligomers.</a> J. Am. Chem. Soc. 136 (5), 2078-2085 (2014).</li><li>Mayo, F. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chain+Transfer+in+the+Polymerization+of+Styrene:+The+Reaction+of+Solvents+with+Free+Radicals1.">Chain Transfer in the Polymerization of Styrene: The Reaction of Solvents with Free Radicals1.</a> J. Am. Chem. Soc. 65 (12), 2324-2329 (1943).</li></ol>

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甲基取代的阳离子[α-二亚胺] NIBR 2 与MAO活化的乙烯聚合催化剂进行其能力为乙烯链转移聚合。将反应物通过气体吸收测量监测，以确定的速率和聚合和催化剂寿命的程度， 并通过凝胶渗透色谱（GPC）测定所获得的聚合物的分子量。最初，镍催化剂进行试验的范围内的乙烯压力（从15-225磅），以确定最佳条件为这个系统在不存在ZnEt 2。使用催化剂的3.33×1...

聚烯烃工业的聚合物与用于热塑性塑料和弹性体的一类重要的。在单点催化剂生产聚烯烃的设计显著进步导致了能够调整分子量，多分散性，和聚合物微结构，这导致了广泛的潜在应用。1-3最近，链转移和链穿梭聚合已经开发，得到附加路由来修改聚合物的性能而无需修改该催化剂。4-6该系统使用单中心过渡金属催化剂和链转移试剂（CTR），它通常是主族金属烷基。在此聚合中，正在生长的聚合物链是能够从催化剂的点击率，其中聚合物链保持休眠，直到它被转移回催化剂转移。同时，被转移到催化剂的烷基可以发起肛疗法聚合物链。在链转移聚合，一种催化剂可以启动一个更大数量的链相对于标准催化聚合。聚合物链终止，该链转移金属;因此，进一步的端基功能化是可能的。该系统可用于改变分子量和聚烯烃的分子量分布，7催化上主族金属，第8和涉及multicatalyst系统，如嵌段共聚物特种聚合物的合成Aufbau状烷基链的增长。9， 10 链转移聚合已观察到最常见的与前过渡金属（铪，锆）和烷基锌或烷基铝试剂，尽管实施例在整个过渡金属系存在。5,7,8,11-16在典型的前过渡金属催化剂体系，链转移是快速，高效，可逆导致窄的分子量分布。章艾因传输/穿梭已中旬至下旬的过渡金属 （如铬，铁，钴和镍）与第2组和第12烷基金属，虽然比起早期的金属传输的速率变化很大。4,7被观察到， 17-19的两个主要因素是所需的必要的有效的链转移:具有良好的金属-碳键离解能匹配的聚合催化剂和链转移试剂，和合适的空间位阻环境以促进烷基桥连的双金属中间体双分子形成/破损20在后过渡金属的情况下，如果催化剂不包含足够的空间体积，β-氢化物（β-H）消除将是占主导地位的终止途径和一般会失竞争的链转移。 本文我们就从镍-2,3- butanediimine类催化剂体系通过SMA双金属链转移到锌的双（2,6-二甲基苯基）二乙基锌与（ZnEt 2）的研究报告LL-大规模高通量的反应。链转移将通过检查通过凝胶渗透色谱分析中的变化分子量（M w）的和所得到的聚乙烯的分散度指数来识别。链转移还将通过乙烯基的饱和链端作为链转移剂浓度的函数的比率的13 C NMR分析鉴定。传播和链转移的速率的深入动力学分析也将提交。

<table><tbody><tr><td>Endeavor Pressure Reactor</td><td>Biotage</td><td>EDV-1N-L</td><td></td></tr><tr><td>Blade Impellers</td><td>Biotage</td><td>900543</td><td></td></tr><tr><td>Glass Liners</td><td>Biotage</td><td>900676</td><td></td></tr><tr><td>2,3-butanedione, 99%</td><td>Alfa Aesar</td><td>A14217</td><td></td></tr><tr><td>2,6-dimethylaniline, 99%</td><td>Sigma Aldrich</td><td>D146005</td><td></td></tr><tr><td>formic acid, 95%</td><td>Sigma Aldrich</td><td>F0507</td><td></td></tr><tr><td>methanol, 99.8%</td><td>Sigma Aldrich</td><td>179337</td><td>ACS Reagent</td></tr><tr><td>nickel (II) bromide, 99%</td><td>Strem</td><td>28-1140</td><td>anhydrous, hygroscopic</td></tr><tr><td>triethylorthoformate, 98%</td><td>Sigma Aldrich</td><td>304050</td><td>dried with K&lt;sub&gt;2&lt;/sub&gt;CO&lt;sub&gt;3&lt;/sub&gt; and distilled</td></tr><tr><td>1,2-dimethoxyethane, 99.5%</td><td>Sigma Aldrich</td><td>259527</td><td>dried with Na/Benzophenone and distilled</td></tr><tr><td>pentane, 99%</td><td>Fisher</td><td>P399</td><td>HPLC Grade *</td></tr><tr><td>dichloromethane, 99.5%</td><td>Fisher</td><td>D37</td><td>ACS Reagent *</td></tr><tr><td>toluene, 99.8%</td><td>Fisher</td><td>T290</td><td>HPLC Grade *</td></tr><tr><td>methylaluminoxane</td><td>Albemarle</td><td>MAO</td><td>pyrophoric, 30% in toluene</td></tr><tr><td>diethylzinc, 95%</td><td>Strem</td><td>93-3030</td><td>pyrophoric</td></tr><tr><td>1,2,4-trichlorobenzene, 99%</td><td>Sigma Aldrich</td><td>296104</td><td></td></tr><tr><td>1,1,2,2-tetrachloroethane-D2, 99.6%</td><td>Cambridge Isotopes</td><td>DLM-35</td><td></td></tr></tbody></table>

ethylene polymerizations using parallel pressure reactors and a kinetic analysis of chain transfer polymerization

我们证明高通量催化剂使用平行压力反应器由镍α-二亚胺乙烯聚合催化剂的初始合成起始筛选的方法。初始聚合用催化剂导致优化的反应条件，包括催化剂浓度，乙烯压力和反应时间。使用气体摄取数据用于这些反应的，一个过程来计算传播（K p）的初始速率呈现。使用优化的条件下，镍α二亚胺聚合催化剂的能力乙烯聚合期间经历与二乙基锌（ZnEt 2）链转移进行了研究。的过程来评估催化剂的经过链转移（从分子量和 13 C NMR数据），计算链转移的程度，并计算链转移速率（K e）中呈现的能力。

乙烯气体消耗与时间的关系示于图1所测试的不同的乙烯压力。这个数据被用于确定优化的反应条件。乙烯气体消耗与时间的关系示于图2A中用于催化剂单独的样品，其中用于计算传播（K p）的速率。 图2B示出的凝胶渗透色谱（GPC）用于链转移聚合痕迹与0-1,000当量二乙基锌。 GPC的用于计算的聚合物样品，其示</stro...

Watch this Scientific Journal Video about Ethylene Polymerizations Using Parallel Pressure Reactors and a Kinetic Analysis of Chain Transfer Polymerization at JoVE.com

Ethylene Polymerizations Using Parallel Pressure Reactors and a Kinetic Analysis of Chain Transfer Polymerization

一种协议，用于聚合催化剂，链转移聚合，聚乙烯表征和反应动力学分析的高通量分析，提出。

乙烯聚合中使用并联电抗器的压力和链转移聚合的动力学分析

We demonstrate a method for high-throughput catalyst screening using a parallel pressure reactor starting from the initial synthesis of a nickel ...

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12.7K 次观看.  University of Minnesota - Twin Cities. 一种协议，用于聚合催化剂，链转移聚合，聚乙烯表征和反应动力学分析的高通量分析，提出。 

视频: Ethylene Polymerizations Using Parallel Pressure Reactors and a Kinetic Analysis of Chain Transfer Polymerization

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst

A standardized technique for atom transfer radical polymerization of vinyl monomers using perylene as a visible-light photocatalyst is presented. The procedure is performed under an inert atmosphere using air- and water-exclusion techniques. The outcome of the polymerization is affected by the ratios of monomer, initiator, and catalyst used as well as the reaction concentration, solvent, and nature of the light source. Temporal control over the polymerization can be exercised by turning the visible light source off and on. Low dispersities of the resultant polymers as well as the ability to chain-extend to form block copolymers suggest control over the polymerization, while chain end-group analysis provides evidence supporting an atom-transfer radical polymerization mechanism.

A method for the atom transfer radical polymerization of functionalized vinyl monomers using perylene as a visible-light photocatalyst is described.

使用苝作为可见光光催化功能化的乙烯基单体原子转移自由基聚合

A standardized technique for atom transfer radical polymerization of vinyl monomers using perylene as a visible-light photocatalyst is presented. The ...

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Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by &#960;-&#960; Stacking Interactions

In this study, an amphiphilic copolymer that includes a core-forming block with phenyl groups was synthesized by living anionic polymerization of phenyl glycidyl ether (PheGE) on methoxy-polyethylene glycol (mPEG-b-PPheGE). Characterization of the copolymer revealed a narrow molecular distribution (PDI &#60; 1.03) and confirmed the degree of polymerization of mPEG122-b-(PheGE)15. The critical micelle concentration of the copolymer was evaluated using an established fluorescence method with the aggregation behavior evaluated by dynamic light scattering and transmission electronic microscopy. The potential of the copolymer for use in drug delivery applications was evaluated in a preliminary manner including in vitro biocompatibility, loading and release of the hydrophobic anti-cancer drug doxorubicin (DOX). A stable micelle formulation of DOX was prepared with drug loading levels up to 14% (wt%), drug loading efficiencies &#62; 60% (w/w) and sustained release of drug over 4 days under physiologically relevant conditions (acidic and neutral pH, presence of albumin). The high drug loading level and sustained release is attributed to stabilizing &#960;-&#960; interactions between DOX and the core-forming block of the micelles.

The key steps of living anionic polymerization of phenyl glycidyl ether (PheGE) on methoxy-polyethylene glycol (mPEG-b-PPheGE) are described. The resulting block copolymer micelles (BCMs) were loaded with doxorubicin 14% (wt%) and sustained release of drug over 4 days under physiologically relevant conditions was obtained.

一个两亲性共聚物的阴离子聚合通过π-π堆积作用稳定嵌段共聚物胶束的制备

In this study, an amphiphilic copolymer that includes a core-forming block with phenyl groups was synthesized by living anionic polymerization of phenyl ...

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, allowing for the synthesis of isotactic poly(&#945;-hydroxy acids) with expected molecular weights (&#62;140 kDa) and narrow molecular weight distributions (Mw/Mn &#60; 1.1). This ring-opening polymerization is mediated by Ni and Zn complexes in the presence of an alcohol initiator and a photoredox Ir catalyst, irradiated by a blue LED (400 - 500 nm). The polymerization is performed at a low temperature (-15 &#176;C) to avoid undesired side reactions. The complete monomer consumption can be achieved within 4 - 8 hours, providing a polymer close to the expected molecular weight with narrow molecular weight distribution. The resulted number-average molecular weight shows a linear correlation with the degree of polymerization up to 1000. The homodecoupling 1H NMR study confirms that the obtained polymer is isotactic without epimerization. This polymerization reported herein offers a strategy for achieving rapid, controlled O-carboxyanhydrides polymerization to prepare stereoregular poly(&#945;-hydroxy acids) and its copolymers bearing various functional side-chain groups.

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

A protocol for the controlled photoredox ring-opening polymerization of O-carboxyanhydrides mediated by Ni/Zn complexes is presented.

镍/锌配合物介导的O-Carboxyanhydrides 的控制 Photoredox 环开聚合

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, ...

Kinetics of Addition Polymerization to Polydimethylsiloxane

Source: <a href="https://www.jove.com/author/Kerry+M._Dooley">Kerry M. Dooley</a> and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA
Polymers are molecules consisting of many repeating monomer units that are chemically bonded into long chains. They exhibit a broad range of physical properties, which are affected by their chemical structure, molecular weight and degree of polymerization. The polymer industry manufactures thousands of raw materials used in a broad variety of commercial products.1,2
The goal of this video is to perform an addition polymerization reaction and then evaluate the resulting product to understand how viscosity can be used to determine polymer molecular weight. Additionally, this experiment will investigate how molecular weight can be related to monomer conversion.

Synthesis of Polydimethylsiloxane via Addition Polymerization

烷的加入聚合动力学

Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA
Polymers are molecules ...

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Free-Radical Chain Reaction and Polymerization of Alkenes

The conversion of alkenes to macromolecules called polymers is a reaction of high commercial importance. The structure of the polymer is defined by a repeating unit, while the terminal groups are considered insignificant. The average degree of polymerization represents the number of repeating units in the polymer molecule and is denoted by the subscript n.
<img alt="Figure1" src="/files/ftp_upload/11773/11773_PT_Figure_1.svg" style="text-align: center; height: 60px;" />
Alkenes undergo polymerization via a free-radical mechanism involving three steps: initiation, propagation, and termination.&#160;
Radicals are generated in the initiation step by heating a small quantity of free-radical initiators such as benzoyl peroxide. The benzoyloxy radical loses CO2 and forms a phenyl radical (Ph&#183;), which adds to the double bond of the alkene to initiate the polymerization process. One of the electrons of the alkene &#960; bond pairs with one electron from the phenyl radical to form a new C&#8211;C bond.
<img alt="Figure2" src="/files/ftp_upload/11773/11773_PT_Figure_2.svg" style="text-align: center; height: 60px;" />
<img alt="Figure3" src="/files/ftp_upload/11773/11773_PT_Figure_3.svg" style="text-align: center; height: 60px;" />
<img alt="Figure4" src="/files/ftp_upload/11773/11773_PT_Figure_4.svg" style="text-align: center; height: 80px;" />
In the propagation step, the carbon radical generated in the initiation step adds to another molecule of alkene to generate a new radical. The continuous addition of alkene monomers at the radical site yields the polymer.
<img alt="Figure5" src="/files/ftp_upload/11773/11773_PT_Figure_5.svg" style="text-align: center; height: 80px;" />
The termination step of the free-radical mechanism occurs via recombination or disproportionation. In a recombination step, two growing chains form a bond at their radical sites.
<img alt="Figure6" src="/files/ftp_upload/11773/11773_PT_Figure_6.svg" style="text-align: center; height: 60px;" />
In termination by disproportionation, a &#946;-hydrogen atom is transferred from one radical to another radical center, resulting in two non-radical products.
<img alt="Figure7" src="/files/ftp_upload/11773/11773_PT_Figure_7.svg" style="text-align: center; height: 300px;" />
The free-radical polymerization of ethylene yields low-density polyethylene (LDPE), where the low density is a consequence of significant branching in the polymer chains. Articles made from polymers surround us in various forms, such as food packaging materials, plastic bags, bottles, stationery, and automotive parts.

Free-radical Polymerization Reaction of Alkenes

烯烃的自由基链式反应和聚合

The conversion of alkenes to macromolecules called polymers is a reaction of high commercial importance. The structure of the polymer is defined by a ...

有机化学

Unit 1

烯烃的反应

关键术语与概念

Radical Chain-Growth Polymerization: Overview

Chain-growth or addition polymerization is successive addition reactions of monomers with a polymer chain. In radical chain-growth polymerization, the reaction proceeds via a free-radical intermediate. The free radical is formed from radical initiators, which spontaneously generate free radicals by homolytic fission. Organic peroxides (such as dibenzoyl peroxide, as shown in Figure 1) or azo compounds are popular radical initiators. A low concentration ratio of radical initiator to monomer is used to minimize radical coupling.
<img alt="Figure1" src="/files/ftp_upload/12920/12920_PT_Figure_1.svg" style="text-align: center; height: 75px;" />
Figure 1: The homolytic fission reaction of radical initiator dibenzoyl peroxide to generate benzoyloxy radicals and the subsequent decomposition to phenyl radicals
This free radical initiates polymerization by reacting with a monomer molecule. Unsaturated monomers are suitable for radical chain-growth polymerization; a substituent group across the unsaturated bond that stabilizes the free radical increases the reaction feasibility. Ethylene, propylene, vinyl chloride, and styrene are examples of monomers that can be polymerized via free-radical chain-growth polymerization.
The reaction between a monomer and a free radical generates a new free radical. This new radical reacts with another monomer and creates yet another free radical. The polymer chain grows as the reaction between free-radical intermediates and monomers repeats sequentially. Typically, the propagation step repeats one thousand to ten thousand times before the termination of polymerization.
Often, chain transfer reagents, such as thiol, are used to control the molecular weight (Figure 2). A chain transfer agent must be sufficiently reactive to transfer a hydrogen atom to the growing chain to terminate the polymer growth. The resultant radical must add to a double bond in the monomer to initiate polymerization.
<img alt="Figure2" src="/files/ftp_upload/12920/12920_PT_Figure_2_.svg" style="text-align: center; height: 150px;" />
Figure 2: (Top): The termination reaction of chain transfer agent thiol and a growing polymer chain; (Bottom): Subsequent reaction of thiol radical and monomer molecule to initiate polymer growth
Inhibitors are the reagents used to reduce the reactivity of radicals in the growing polymer chain. Figure 3 depicts the reaction of benzoquinone as an inhibitor.
<img alt="Figure3" src="/files/ftp_upload/12920/12920_PT_Figure_3.svg" style="text-align: center; height: 200px;" />
Figure 3: The reaction between chain inhibitor benzoquinone and a growing polymer chain to generate a less reactive free radical

自由基链生长聚合:概述

Chain-growth or addition polymerization is successive addition reactions of monomers with a polymer chain. In radical chain-growth polymerization, the ...

Synthetic Polymers

Radical Chain-Growth Polymerization: Mechanism

The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization initiates when a free radical generated from the radical initiator adds to the unsaturated bond in the monomer. The unpaired electron of the free radical and one &#960; electron in the unsaturated bond creates a &#963; bond between the free radical and the monomer. As a result, the other &#960; electron in the unsaturated bond converts this species into the new free-radical. The mechanism of the initiation reaction between a phenyl free radical and a vinyl chloride monomer is shown in Figure 1.
<img alt="Figure1" src="/files/ftp_upload/12921/12921_PT_Figure_1.svg" style="text-align: center; height: 85px;" />
Figure 1: The initiation step of the reaction mechanism of the free-radical polymerization of vinyl chloride using a phenyl free radical.
The propagation step is the addition of this new free radical to the unsaturated bond in another monomer. This propagation step repeats to add more monomers and grow the polymer chain. In each addition, the radical site shifts to the newly added monomer. The number of times the propagation step repeats determines the molecular weight of the polymer chain. The propagation step of vinyl chloride free-radical polymerization is shown in Figure 2.
<img alt="Figure2" src="/files/ftp_upload/12921/12921_PT_Figure_2.svg" style="text-align: center; height: 105px;" />
Figure 2: The propagation step of the reaction mechanism of the free-radical polymerization of vinyl chloride.
The monomers add preferentially such that the unpaired electron is positioned on the more substituted carbon. For example, monosubstituted ethylene monomers such as propylene, vinyl chloride, and styrene add to the growing chain in a head-to-tail manner. Here, the radical site in the growing polymer chain is always on the substituted carbon (tail).
Due to the high reactivity of radical intermediates, the termination of polymer growth is inevitable. Different reaction pathways lead to the termination of polymerization. One is the coupling reaction of a radical site in a growing chain with a radical site in another. Another way of termination is the radical disproportionation reaction, where the radical site of one growing polymer chain abstracts hydrogen from the &#945; carbon of the radical site in the other chain. So, the former chain is terminated with an alkyl group, and the latter is terminated with an alkenyl group. The reaction mechanisms of radical coupling and disproportionation in the termination of the growth of a poly(vinyl chloride) chain are depicted in Figure 3.
<img alt="Figure3" src="/files/ftp_upload/12921/12921_PT_Figure_3.svg" style="text-align: center; height: 225px;" />
Figure 3: The termination of vinyl chloride polymerization via radical coupling (top) and disproportionation reaction (bottom).
Chain transfer reagents and chain inhibitors can also terminate a polymer chain&#39;s growth. However, in this case, the radical site is not eliminated but either removed from the growing chain or made less reactive.

自由基链生长聚合:机理

The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization ...

Radical Chain-Growth Polymerization: Chain Branching

The skeletal structure of polymers synthesized via radical polymerization is always branched. For example, the polymerization of ethylene by radical polymerization results in a low-density grade of polyethylene with a heavily branched skeletal structure. Here, the radical site abstracts hydrogen from the growing chain, and the radical site shifts from the end (a primary carbon center) to anywhere within the growing chain (a secondary carbon center). Consequently, the part of the chain from the abstraction site to the end of the chain becomes a branch.
In intermolecular hydrogen abstraction, the radical site abstracts hydrogen from another growing polymer chain and terminates its chain growth. A new branch grows in the other chain where the hydrogen was removed. Figure 1 demonstrates the intermolecular hydrogen abstraction and the consequent chain growth from the middle of the polymer chain.
<img alt="Figure1" src="/files/ftp_upload/12922/12922_PT_Figure_1.svg" style="text-align: center; height: 125px;" />
Figure 1: The intermolecular hydrogen abstraction (top) and the subsequent addition of the newly formed radical site to a monomer (bottom).
The radical site abstracts hydrogen from the same growing chain in intramolecular hydrogen abstraction. The length of the branch depends on the distance between the radical site and the abstraction site. Intramolecular 1,5-hydrogen abstraction frequently occurs due to the relatively stable six-membered transition state, resembling the chair conformation of cyclohexane. The resultant butyl branches are commonly found in branched polymers. Figure 2 shows the intramolecular hydrogen abstraction and the formation of the butyl branch.
<img alt="Figure2" src="/files/ftp_upload/12922/12922_PT_Figure_2v2.svg" style="text-align: center; height: 60px;" />
Figure 2:&#160; The intramolecular hydrogen abstraction (top) and subsequent addition of the newly formed radical site on a monomer (bottom).
In general, intramolecular hydrogen abstraction is more probable than intermolecular hydrogen abstraction. Also, short-chain branching is more common than long-chain branching, as the ends of the chains are more accessible.

自由基链生长聚合:链支化

The skeletal structure of polymers synthesized via radical polymerization is always branched. For example, the polymerization of ethylene by radical ...

Anionic Chain-Growth Polymerization: Mechanism

The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic anion, such as butyl lithium, initiates the polymerization process by attacking the &#960; bond of the vinylic monomer. As a result, a carbanion, stabilized by the electron&#8208;withdrawing group, is generated. The resulting carbanion acts as a Michael donor in the propagation step and attacks the second vinylic monomer, which acts as a Michael acceptor. Consequently, a dimer is formed that acts as a new carbanion. The propagation step repeats itself, thereby enabling the polymer chain to extend. The polymer chain continues to grow until a weak acid or an electrophile is added to terminate the polymerization process. Interestingly, in the absence of any terminating agents, the propagating chain&#8217;s end acts as a stabilized carbanion site, and the polymerization process continues uniformly as long as the monomers are available. Therefore, anionic polymers are often referred to as living polymers.

阴离子链生长聚合:机理

The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic ...

Cationic Chain-Growth Polymerization: Mechanism

The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the &#960; bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the &#960; bond generates a carbocation stabilized by the electron&#8208;donating group. In the propagation step, the &#960; bond of the second monomer acts as a nucleophile and attacks the generated carbocation, thereby producing a dimer that acts as a new carbocation. The propagation step repeats itself and builds the polymer chain. In the termination step, the propagating chain gets terminated either by adding a base that deprotonates the carbocation and forms a new &#960; bond or by the attack of a nucleophile on the carbocation, where the nucleophile adds to the cationic end of the chain.

阳离子链生长聚合:机理

The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization ...