乙炔在三异丙醇钕盐络合催化体系中的定向聚合

本文研究了乙炔在三异丙醇钕盐[Nd(O-i-Pr)_3]-三烷基铝(AIR_3)-第Ⅲ组份(Ⅲ)络合催化体系中定向聚合的规律。发现在所用稀土络合催化体系中,催化活性不仅与第Ⅲ组份(Ⅲ)添加量有关,而且与铝和钕的摩尔比[AlR_3/Nd(O-i-Pr)_3]有着密切的关系,每种添加剂各有其显示最佳添加效应的铝、钕摩尔比和添加量。同时发现,聚乙炔的顺式含量,除与温度有关外,亦符合上述规律。从而进一步提高了稀土络合催化体系的活性以及聚乙炔膜的顺式含量,在30～5℃制得了高顺式(90—99.5％)具有金属光泽的银色聚乙炔薄膜。此外,本文用红外光谱、顺磁共振、扫描电子显微镜、X衍射、热分析及电阻率、密度测定等对聚乙炔膜进行了表征。     

Nd(P204)3/AlEt3/第三组分体系催化乙炔聚合动力学

本文研究了乙炔在Nd(P)_3-AlEt_3-Ⅲ组分体系中的聚合动力学。结果表明聚合速率R_p与乙炔压力和催化剂浓度分别呈一级关系,即R_p=k＇[cat][P];发现聚合速率随时间按二级定律衰减,即dR~(-1)dt=k;提出活性中心以双分子失活的假设解释了实验结果。     

稀土络合催化苯乙炔直接成膜聚合 Ⅴ.苯乙炔在钕、铁混合络合催化体系中的直接成膜聚合

乙酰丙酮(AA)、苯酰丙酮(BA)为配体的钕(Nd)、铁(Fe)混合催化剂与三异丁基铝[Al(i-Bu)_3]组成络合催化体系,能使苯乙炔在甲苯/己烷混合溶剂中直接聚合成膜。研究了其聚合反应规律及动力学行为,并对聚苯乙炔膜进行了全面表征,揭示了钕、铁两组分催化剂具有协同催化效应。     

稀土络合催化苯乙炔直接成膜聚合 Ⅴ.苯乙炔在钕、铁混合络合催化体系中的直接成膜聚合

 乙酰丙酮(AA)、苯酰丙酮(BA)为配体的钕(Nd)、铁(Fe)混合催化剂与三异丁基铝[Al(i-Bu)₃]组成络合催化体系,能使苯乙炔在甲苯/己烷混合溶剂中直接聚合成膜。研究了其聚合反应规律及动力学行为,并对聚苯乙炔膜进行了全面表征,揭示了钕、铁两组分催化剂具有协同催化效应。     

丁二烯在氯化稀土-乙醇-烷基铝催化体系中的某些动力学规律 Ⅲ.NdCl_3-C_2H_5OH-AlR_3体系中的聚合动力学

本文应用氚醇淬灭法和动力学方法测定了NdCl_3-C_2H_5OH-AlR_3-丁二烯聚合体系的活性中心浓度及反应速度常数。结果表明:其活性中心浓度在05-2.8×10~(-2)mol/mol Nd内变化。固定温度时,在所研究,的范围内,其增长速度常数不随烷基铝种类及其它聚合条件而改变,但对烷基铝链转移速度常数影响显著。     

改性甲基铝氧烷和烷基铝活化的新癸酸钕催化剂催化异戊二烯聚合

 考察了改性甲基铝氧烷(MMAO,溶于庚烷)和烷基铝(AlR3)活化的新癸酸钕(Nd(vers)3)催化剂对异戊二烯(IP)聚合反应的催化性能. 结果表明,以Al(i-Bu)2H替代部分MMAO,可在较低的MMAO用量(n(MMAO)/n(Nd)=20,总铝量n(Al)/n(Nd)=40)下明显提高Nd(vers)3-MMAO催化剂的活性,但所得聚合物中顺式-1,4结构的含量较低(约90%). Nd(vers)3, MMAO, Al(i-Bu)2H和Al(i-Bu)2Cl可在少量单体(n(IP)/n(Nd)=10)存在下配制成稳定的均相催化剂,该催化剂能在相对较低的MMAO用量(n(MMAO)/n(Nd)=15,总铝量n(Al)/n(Nd)=30)及较宽的Al(i-Bu)2Cl用量范围(n(Cl)/n(Nd)=0.5～7.0)内聚合异戊二烯,其活性明显高于单独以MMAO或Al(i-Bu)2H组成的催化剂,所得聚合物中顺式-1,4结构含量可达96%. 调节MMAO和Al(i-Bu)2H用量可控制聚合产物的分子量. 初步推测了该四元均相催化剂活性中心的生成过程.     

希土化合物在定向聚合中的催化活性——Ⅱ.希土螯合物与三烷基铝组成的均相体系对丁二烯定向聚合的催化活性

本工作研究了β-二酮类希土螯合物与三烷基铝组成的均相体系对丁二烯定向聚合的催化活性及一些聚合规律。实验结果表明下列希土螯合物与三乙基铝组合时都具有使丁二烯进行顺式-1,4定向聚合的催化活性:NdB_3;NdB;NdBTA;NdTTA;PrB_3;PrB;PrBTA;PrTTA;YB_3;YBTA 以及 LaBTA 等。这些均相催化体系的活性远比非均相希土氯化物体系的高。在一定的催化剂浓度范围内,催化活性随着Al/希土及希土/丁(克分子比)的增高而增大。聚合反应速率对单体浓度呈一级关系,对希土螯合物浓度也近似呈 一级关系,并呈现一诱导期。丁二烯在 NdB_3-Al(C_2H_5)_3体系中聚合的总活化能为 13±0.5千卡/克分子。研究不同希土元素的这些螯合物表明同一元素的不同螯合物体系的聚合反应速率和聚合物链结构都没有显著的差别。但不同希土元素的同一整合物体系的聚合活性相差较大,含有镨和钕螯合物体系的活性比其他体系大。由这些均相催化体系所得聚丁二烯的1,2链节含量不超过1％,都不含或含很少量凝胶,聚合物的[η]随着Al/希土(克分子比)以及希土/丁(克分子比)的增大而降低,[η]可以从 4—5降至 1以下。Al(i-C_4H_9)_3也能与这些螯合物组成活性催化体系,但活性很低。Al(C_2H_5)_2Cl则不能与这些螯合物构成活性催化体系。     

稀土化合物催化内酯开环聚合(Ⅲ)──氯化钕-环氧化合物体系催化ε

Bulk polymerization of ε-caprolactone(CL) with neodymium chloride-epoxide sys tem has been studied. It was found that the addition of epoxide can greatly increase the catalytic activity of neodymium chloride. The catalytic activity sequence of NdCl₃ combined with epoxide is: NdCl₃-ethylene oxide > NdCl₃-proplene oxide > NdCl₃-epichlorohydrin≈NdCl₃-allyl glycidyl ether. The catalytic activity of NdCl₃-proplene oxide system increases,but molecular weight of resulting polycaprolactone(PCL) decreases at higher proplene oxide/ neodymium chloride molar ratio.The molecular weight of PCL can be controlled by catalyst concentration. Higher polymerization temperature can greatly increase the catalytic efficien cy. At 30℃, PCLwith molecular weight as high as 28. 9×10⁴can be prepared easily with an activity of 44×10⁴g PCLper molar neodymium, and at 60℃, the molecular weight of PCLand catalytic efficiency increased to 42×10⁴and 10⁶g PCL/mole Nd respectively.     

氯化铁络合物—烷基铝体系催化丁二烯聚合的研究

本文研究了一类新型的二元铁催化剂:FeCl_n·3L(n=2或3,L为P_(350)或磷酸三丁酯)-AIR_3对丁二烯聚合的某些规律。结果表明,它们对丁二烯聚合具有很高的催化活性,并且可使其聚合成顺1,4含量为75％左右,1,2含量为25％左右的聚丁二烯。单体浓度,不同铁络合物,AIR_3用量和聚合温度对丁二烯聚合反应均有显著的影响。     

THE POLYMERIZATION OF ACETYLENE BY COORDINATION CATALYSTS COMPOSED OF NEODYMIUM COMPOUND, ALUMINUM TRIALKYL AND A THIRD COMPONENT

This paper describes the polymerization of acetylene by coordination catalysts composed ofvarious neodymium compounds, (Nd (P_(204))_3; Nd (P_(507))_3; Nd (NO_3)_3 3P_(350); Nd (BA)_3.2H_2O; andNd (acac)_3.2H_2O), aluminum trialkyl and an electron donor. The catalysts show fairly high catalyticactivity and high cis stereospecificity on acetylene polymerization at 30℃.     

丁二烯在含有机镁铝络合物稀土催化剂中的聚合

本文研究定向稀土催化剂组份中引入镁铝络合物后对丁二烯聚合的影响。改变镁铝络合物与氯化物的种类和用量,皆明显的影响其聚合活性。当催化剂中含有苯基镁的烷基铝络合物时,聚丁二烯反-1,4链节可达36%。选择适当的催化剂组成和配比时,含镁稀土定向催化剂具有较高的聚合活性。     

甲基丙烯酸甲酯、丁酯在钕盐催化体系中聚合动力学和机理研究

采用Ｎｄ（Ｐ５０７）３－Ａｌ（ｉ－ＢＵ）３聚合体系催化甲基丙烯酸甲酯（ＭＭＡ）和甲基丙烯酸丁酯（ＢＭＡ）聚合．发现介质对聚合反应速率影响甚大．在石油醚中聚合反应速率与单体（ＭＭＡ、ＢＭＡ）、钕盐的浓度分别呈一级关系．ＭＭＡ．ＢＭＡ聚合的表现活化能分别为３３ｋＪ．ｍｏｌ－１和２４ｋＪ．ｍｏｌ－１．ＰＭＭＡ的间同含量达７０％左右．聚合反应属配位自由基机理．     

RING OPENING POLYMERIZATION OF PROPYLENE SULFIDE BY RARE EARTH COORDINATION CATALYSTS*

Ring opening polymerization of propylene sulfide using rare earth coordination catalysts has been investigated for the first time. It has been found that trinary rare earth coordination catslysts composed of rare earth compounds of phosphonate, naphthenate or acetylacetonate, trialkyl sluminum and water are effective catalysts for the polymerization of propylene sulfide. The polymerization in toluene is a homogeneous reaction. High molecular weight as high as several million poly(propylene sulfide) with high yield can be prepared by these catalysts. Kinetic studies showed that the polymerization rate is of first order with respect to both monomer concentration and catalyst concentration. The activation energy of the polymerization reaction is 61.4 k fJ/mol. The structure of the polymers so obtained has also been characterized by ~(13)C NMR spectroscopy, X-ray diffraction, gel permeation chromatography and differential scanning calorimetry.     

COORDINATION COPOLYMERIZATION OF STYRENE WITH MALEIC ANHYDRIDE BY RARE-EARTH COORDINATION CATALYSTS

The study on coordination copolymerization of styrene (S) with maleic anhydride (MA) by rare-earth coordination catalysts, NdL_3-Al(i-Bu)_3, has been successfully carried out for the first time. Some features, kinetic behavior, and mechanism of the SMA copolymerization by Nd(naph)_3-Al(i-Bu)_3 system are described and discussed. The copolymex of styrenemaleic anhydride prepared by the NdL_3-Al(i-Bu)_3 systems in benzene at 50℃ is an alternating-rich white powder having high number-average molecular weight of 6—8.5×10~5. The overall activation energy for the polymerization was found to be 10.5KJ/mol. The polymerization was not suppressed by addition of hydroquinone. The catalytic activity of various ligands in NdL_3 for the copolymerization decreases in the following order: Nd (naph)_3>Nd-(P_(507))_3～NdCl_3-6H_2O>Nd(P_(204))_3>Nd(acac)_3. 3H_2O. The experimental results are explained based on a mechanism to be the coordination-type copolymerization in terms of the participation of a monomer-monomer c     

稀土络合催化环氧乙烷聚合

以稀土化合物-二(2-乙基己基)膦酸钕[Nd(P_(204)_3],三异丁基铝和水组成的络合催化剂,引发环氧乙烷聚合.结果表明,稀土络合催化剂是制备高分子量聚环氧乙烷的新型催化剂.聚合反应速度与环氧乙烷浓度呈一级关系,与Nd(P_(204))_3浓度呈一级关系.聚合的总活化能E_α=33.8kJ/mol,表观速率常数K_p=1.67×10~(-3)s~(-1)·mol~(-1)·1     

环氧化物稀土络合催化开环聚合动力学研究

用膨胀计方法研究环氧丙烷、环氧氯丙烷在稀土络合催化剂 Nd(P_(204))_3-Al(i-Bu)_3-H_2O作用下的聚合反应动力学,表明聚合反应速度对催化剂浓度及单体浓度均呈一级关系。环氧丙烷、环氧氯丙烷开环聚合反应活化能分别为61.3kJ/mol和48.9kJ/mol。在同样的聚合反应条件下,环氧氯丙烷聚合反应速度大于环氧丙烷聚合反应速度。 研究还发现,催化剂组成摩尔比Al/Nd及H_2O/Al对聚合反应速度均有一定影响;各种稀土元素络合催化剂催化活性顺序为:Nd>La>Dy>Yb>Eu;稀土络合物中配体对活性的影响为:acac>P_(204)>P_(507)>naph;烷基铝的影响为:Al(i-Bu)_3>AlEt_3。     

CRYSTALLIZATION KINETICS OF ETHYLENE-PROPYLENE COPOLYMERS PREPARED BY LIVING COORDINATION POLYMERIZATION

In this paper,crystallization kinetics of a series of ethylene-propylene copolymers prepared by living polymerization coordination catalyzed by a fluorinated bis(phenoxyimine)Ti catalyst(FI-EP copolymers)was studied,and was compared with that of ethylene-propylene copolymers prepared by a conventional Ziegler-Natta catalyst(ZN-EP copolymers).It is found that,the Avrami exponent and the crystallization rate constant of the FI-EP and ZN-EP copolymer show similar dependence on crystallization temperature,bu...     

乙炔在钍配合物催化体系下的聚合

<正> 聚乙炔掺入杂质后,做为高分子导电材料已引起人们的极大关注。有关聚乙炔(下称PA)的合成、结构及性能测试,以及电池研究已有很多报道,其催化剂体系已有关于Ti、V、Cr、W、Fe、Mo、Ni和Co等过渡金属化合物,稀土化合物合成PA的报道。本文进行了应用重元素钍的高配合物[Th(P_(204))_8Cl_4]与三乙基铝组合作为催化剂、使乙炔在常温下定向聚合的研究,得到具有余属光泽银白色的PA,顺式含量为80％,并对PA薄