含分子内配位Ln←O键的稀土有机化合物催化甲基丙烯酸甲酯聚合

 采用含有分子内配位Ln←O键、茂(茚)和环辛四烯(COT)混合配体的稀土有机化合物与三乙基铝体系催化甲基丙烯酸甲酯(MMA)的聚合,可以得到高分子量(Mη＞100×103),窄分子量分布(Mw/Mn＜3)的聚甲基丙烯酸甲酯(PMMA). 不同的配体及稀土元素可以影响这类稀土有机化合物的催化聚合活性. 化合物(η5-MeOCH2CH2C5H4)Nd(η8-C8H8)(THF)具有较高的活性(转化率91.0%,Mη=115.2×103). 考察了催化剂和助催化剂浓度,以及聚合温度和时间对(η5-cyclo-C4H7OCH2C9H6)Dy(η8-C8H8)/AlEt3体系催化聚合反应的影响. 结果表明,最佳聚合条件为: n(MMA)∶n(催化剂)∶n(助催化剂)=1?200∶1∶5,θ=60 ℃,t=32 h. 利用核磁共振和凝胶渗透色谱等技术对聚合物进行了表征.     

可溶性稀土聚乙炔的合成及其聚合机理的研究

研究了各种催化体系、催化剂浓度及聚合条件对催化效率(f)和聚乙炔分子量()的影响。发现Nd(i-OC_3H_7)-AlR_3(R=C_2H_5,i-C_4H_9)催化体系可获得较大的可溶分数(q)。催化剂浓度、Al/Nd克分子比和聚合温度对f、及q均有一定影响。可溶性Nd(i-OC_3H_7)_3-AlR_3催化体系的UV光谱证实、Nd的价态与AlR_3混合与AlR_3混合后保持不变。PA的IR光谱示出,Nd(i-OC_3H_7)_3-Al(C_2H_5)_3及Nd(i-OC_3H_7)_3-Al(i-C_4H_9)_3体系获得的聚合物分别含有CH_3CH_2—和(CH_3)_2CHCH_2—末端基。上述结果表明,乙炔的聚合可能是通过单体在Nd-C键之间的插入进行的。     

甲基丙烯酸十六酯溶液聚合

甲基丙烯酸十六酯在有机溶剂中聚合时,溶剂结构对聚合速度没有显著影响。聚合体的平均分子量主要是受溶剂的链转移常数控制的,但在聚合过程中当生成的高聚物分子具有近似平均分子量时,由于高聚物分子在不同溶剂中具有不同的分子形态所产生的不同程度的粘度效应,对高转化率聚合体的平均分子量产生影响;同时,在高转化率聚合过程中聚合体平均分子量的均匀性与高聚物分子在溶剂中的形态有关,而与由聚合物的不同平均分子量在溶剂中所表现的不同粘度无关。     

稀土络合催化苯乙炔直接成膜聚合 Ⅲ.各种稀土环烷酸盐络合催化苯乙炔直接成膜聚合

采用十四种稀土(La、Ce、Pr、Nd、Sm、Eu、Gd、Dy、Ho、Er、Tm、Yb、Lu、Y)环烷酸盐-三异丁基铝络合催化体系,在室温下均能使苯乙炔(PA)于混合溶剂中直接成膜聚合。成膜聚合的最佳条件大致相同;[Ln(naph)_3]=3×10~(-5)mol/ml,[M]=3×10~(-4)mol/ml,Al/Ln:7,V_h/V_t=1。不同稀土元素显示的催化活性次序为Gd>Lu>Nd～Ce>Ho>Sm>Dy～Eu>Er>Pr>>La>Y～Tm>Yb。苯乙炔在含苯溶剂中反应活性较高,在卤代烃中反应活性很低。混合溶剂比单组分溶剂更有利于成膜聚合并有高的催化活性和高的分子量。各种稀土聚苯乙炔膜的结构和性能基本相同。稀土聚苯乙炔为片层结晶,具有较高的结晶性。     

超高分子量聚苯乙烯的合成和聚合反应动力学

杯芳烃钕与Mg(n Bu) 2 、HMPA所组成的三元络合催化剂用于苯乙烯配位聚合能以高收率制得超高分子量聚苯乙烯 .以甲苯为溶剂 ,在一定条件下制成三元配位催化剂 ,当 [Nd]=8× 10 - 4mol L ,[St]=4 .0mol L ,Mg Nd =2 0 .0 (摩尔比 ) ,HMPA Mg =1.0 (摩尔比 ) ,5 0℃聚合 4 5min ,聚合转化率可达到 80 %左右 .所得聚苯乙烯的重均分子量高达 2 10× 10 4 ,分子量分布指数为 1.6 1.间规聚苯乙烯含量为 81% .动力学研究表明 ,聚合反应速率与单体和主催化剂 杯 [6 ]芳烃钕的浓度分别呈 1次方关系 ,聚合反应的表观活化能为 4 1.7kJ mol     

侧链取代基含有氧原子的环戊二烯与席夫碱混合配体的镧系化合物催化甲基丙烯酸甲酯聚合

侧链取代基含有氧原子的环戊二烯与双水杨醛邻环己二胺席夫碱混合配体的镧系化合物[(η5:η1-MeOCH2CH2C5H4)Ln][(μ:η-OC20H20N2O)]2[(η5-MeOCH2CH2C5H4)Ln](Ln=Sm(1),Dy(2)),[(MeOCH2CH2C5H4)2Yb]2(OC20H20N2O)(3),[(C4H7OCH2C5H4)2Dy]2(OC20H20N2O)(4)与三乙基铝体系催化甲基丙烯酸甲酯(MMA)的聚合,可以得到高分子量(粘均分子量Mη>100,000),窄分子量分布(Mw/Mn<3)的聚甲基丙烯酸甲酯(PMMA).不同茂环上的取代基及稀土元素使这类化合物形成了不同的分子结构,并且影响了它们的催化活性.化合物(3)具有较高的活性(转化率∶54.1%,Mη=287.1×103).考察了催化剂浓度,助催化剂浓度,聚合温度和时间对化合物(3)/Al(Et)3体系催化聚合反应的影响,最佳聚合条件为:60℃,24h,MMA∶催化剂∶助催化剂(摩尔比)=1000∶1∶10.利用核磁,凝胶渗透色谱仪(GPC)等对聚合物进行表征.     

WCl_4(OR)_2Al(i-Bu)_3体系合成1,2-聚丁二烯的研究

分析了五种醇与WCl_6在室温下交换反应产物氯含量,表明产物中W:Cl=1:4,故产物可写为WCl_4(OR)_2。以WCl_4(OR)_2-Al(i-Bu)_3为催化体系,在加氢汽油溶剂中可使丁二烯聚合,得到1,2-链节含量在80％,全同立构体在60％以上的聚合物。几种醇中,以n-C_(10)H_(21)OH交换产物的催化活性最高。各种聚合条件的改变,对聚合物微观结构及分子量分布影响不明显。     

茂基稀土邻氨基苯甲酰胺基双负离子配合物的合成及其环胺羰化反应和脒基化反应（英文）

Cp_3Ln与邻氨基苯甲酰胺在甲苯中反应,之后在HMPA和甲苯中结晶,以中等到高收率得到四核稀土有机配合物[CpLn(μ-η~2∶η~2-NHC_6H_4CONH)(μ_3-η~1∶η~1∶η~2-NHC_6H_4CONH)LnCp(HMPA)}2(Ln=Yb,1a;Er,1b;Y,1c)。化合物1与4倍物质的量的Ph NCO在甲苯中反应形成1,3-喹唑啉二氧基(Quo)双负离子稀土配合物[Cp2Ln(μ3-η2∶η2∶η1-Quo)]3Ln(HMPA)2(Ln=Yb,2a;Er,2b;Y,2c),表明化合物1中的Ln-NHAr键和Ar CONH-Ln键能与异氰酸酯分子发生连续加成/胺消除反应,形成1,3-喹唑啉二氧基骨架。但化合物1a~1c与i Pr N=C=NiPr反应,仅得到Ar NH基单加成产物{Cp——2Ln[μ-η~1∶η~1∶η~2-iPrNC(NHiPr)NC_6H_4CONH]}3Ln(HMPA)3(Ln=Yb,3a;Er,3b;Y,3c)。而Cp3Ln与邻氨基苯甲酰胺和i Pr N=C=Ni Pr在甲苯中进行"一锅"反应,则形成双核配合物{CpLn[μ-η~1∶η~2∶η~2-NHCOC_6H_4NC(NHiPr)NiPr]}2(Ln=Yb,4a;Er,4b;Y,4c)。值得注意的是,HMPA能够诱导配合物4发生配体重排反应,转化成化合物3。     

聚二甲基硅氧烷在混合溶剂中的粘度和光散射

用Elias沉淀点法求取聚二甲基硅氧烷25℃在乙苯-邻苯二甲酸二乙酯体系,庚烷-二氧六环体系的θ-溶剂组成。测定了聚二甲基硅氧烷八个级份在甲苯溶液中光散射和两种θ-溶剂中特性粘数,得到 [η]_θ=7.62×10~(-2)(?)_ω~(0.50)乙苯-邻苯二甲酸二乙酯体系γ_ω=19.0％ [η]_θ=8.28×10~(-2)(?)_ω~(0.50)庚烷-二氧六环体系γ_ω=77.2％ 聚二甲基硅氧烷分子无扰尺寸存在溶剂介质依赖性。     

聚合条件对N-羧基-L-丙氨酸-环内酸酐开环聚合产物分子量的影响

用光气法制备了N-羧基-L-丙氨酸-环内酸酐(L-Alanine NCA).系统研究了L-Alanine NCA开环聚合反应过程中引发剂、溶剂、温度对聚合物分子量的影响.用硝基苯作溶剂,三乙胺作引发剂,所得聚合物特性粘度[η]=1.18.实验中发现,L-Alanine NCA可以顺利地进行热聚合反应。反应具有速率快,转化率高,分子量大的特点。甲苯溶剂中反应5小时所得聚合物[η]=2.35,高于采用引发剂的聚合体系产物的相应值。     

THE POLYCONDENSATION OF TEREPHTHALOYL CHLORIDE AND p-PHENYLENEDIAMINE HYDROCHLORIDE IN NMP-CaCl_2 SOLVENT SYSTEM

The solution polycondensation of 1,4-phenylenediamine hydrochloride and terephthaloyl chlo-ride with introducing a tertiary amine in NMP-CaCl_2 solvent system were studied in detail.Effect of reactant concentration, the content of CaCl_2, in NMP solvent and the kinds of tertiary amineon inherent viscosity of PPTA polymer have been studied. High molecular weight PPTA withinherent viscosity over 5 was obtained at 0.35Mol/L of reactant concentration in a solvent of NMP-CaCl_2 with the presence of α-picoline.     

在酰胺-盐溶剂体系中对苯二甲酰氯与对苯二胺的缩聚反应

本文研究了在酰胺-盐溶剂体系中对苯二胺与对苯二甲酰氯的缩聚反应,溶剂对缩聚反应的影响以及溶剂体系与对苯二甲酰氯的副反应。由NMR实验结果表明,聚对苯二甲酰对苯二胺分子中酰胺基团的氢质子由于溶剂化作用向低场方向位移,位移的大小与溶剂的种类及盐的浓度有关。DMAc与NMP两种溶剂体系在缩聚反应过程中皆与对苯二甲酰氟有竞争反应。在该溶剂体系中可得到适于加工成纤的高分子量聚合物。     

Effect of solvent on the reactivity of functional groups in polycondensation reactions

The effect of solvent on solution or interfacial polycondensations was investigated in terms of selectivity and control of functional groups such as amine or hydroxyl groups toward polycondensation reactions. Solution polycondensation of a mixture of resorcinol (RL) and m-xylyenediamine (m-XD) with isophthaloyl chloride was affected by solvents to such extent as to change the course of the polycondensation reaction, and hexamethylenephosphoramide (HMPA) caused the formation of amide-rich polymer, while tetrahydrofuran (THF) was a solvent favoring formation of a polyamide ester with a regular structure. Polycondensation of 3,3′-dihydroxybenzidine (DHB) with isophthaloyl chloride yielded exclusively a linear polyamide in HMPA solution, while with aldehyde as a solvent polyester was obtained owing to the preservation of the amine group. Thus, it was found that the course of polycondensation reactions of monomers having different functional groups could be controlled by selection of a suitable solvent.     

全对位聚芳醚砜醚酮酮的结晶行为研究

以AlCl3/DCE/DMF为溶剂体系,采用低温溶液缩聚合成全对位聚醚砜醚酮酮(p-PESEKK)树脂,研究了端基、分子量及溶剂体系对树脂的溶剂诱导结晶行为的影响.结果表明,在AlCl3/DCE/DMF的良溶剂中制得的p-PESEKK为低结晶度聚合物,由于分子链中四面体结构砜基的影响,树脂熔融后很难再结晶;随脂肪链端基碳原子数的增加,溶剂诱导结晶速度逐渐下降,结晶度降低,与主链结构相同的端基更有利于结晶的形成;高分子量的p-PESEKK端基的比例相对较小,有利于溶剂诱导结晶.     

对苯二胺盐酸盐与对苯二甲酰氯在NMP-CaCl_2溶剂体系中的缩聚反应

<正> 聚对苯二甲酰对苯二胺(PPTA)具有刚性链分子结构,能形成各向异性的高分子液晶溶液,纺丝后可得到性能优异的高模量、高强度的纤维。但是,欲制出高模高强的PPTA纤维,必须先制出高分子量的PPTA聚合体。等曾研究了对苯二胺盐酸盐与对苯二甲酰氯在二甲基乙酰胺-氯化锂(DMAC-LiCl)溶剂体系中合成PPTA的问题。     

Soluble polyimides from a semi-aliphatic diamine containing ester,amide and ether groups

A diamine was synthesized by two successive reactions.Nucleophilic reaction of 4-hydroxybenzoic acid with terephthaloyl chloride yielded terephthaloyl bis(4-oxybenzoic) acid.Then reaction of this compound with 1,8-diamino-3,6- dioxaoctane via Yamazaki method resulted in preparation of diamine named terephthalic acid bis(4-{2-[2-(2-amino ethoxy)ethoxy]ethyl carbamoyl}phenyl) ester.After fully characterization it was used to prepare new polyimides through polycondensation with different dianhydrides using trimethylchlorosilane.Characterization of polymers was achieved by common methods and their physical properties including inherent viscosity,thermal behavior,thermal stability,crystallinity and solubility were studied.Prepared polyimides showed improved solubility and good thermal stability.     

Synthesis and characterization of novel soluble and thermally stable polyamides based on pyridine monomer

Nucleophilic aromatic substitution reaction of 4-aminophenol and also 5-amino-1-naphthol with 2,6-dichloropyridine in N-methyl-2-pyrrolidone (NMP) as solvent, in the presence of potassium carbonate, afforded two aromatic ether diamines. Eight soluble, thermally stable polyamides were prepared by polycondensation reaction of the obtained diamines with aromatic and aliphatic diacid chlorides including terephthaloyl chloride (TPC), isophthaloyl chloride (IPC), adipoyl chloride (AC), and sebacoyl chloride (SC). The prepared monomers and polymers were characterized by conventional spectroscopic methods. Physical and thermal properties of the polymers, such as thermal behavior, thermal stability, solution viscosity, and solubility behavior were also studied.     

Preparation and properties of polyesters and copolyesters based on 4-methyl-2,4-bis (p-hydroxyphenyl)-1-pentene

4-Methyl-2,4-bis (p-hydroxyphenyl)-1-pentene (MBHPP) was prepared from thermal cracking of bisphenol A (BPA). Unsaturated polyesters were synthesized from the polycondensation of MBHPP with diacid chlorides. Three synthetic routes—solution, interfacial, and melt polycondensation—were employed. MBHPP-polyesters with higher molecular weights were obtained by the interfacial polycondensation reaction. During the preparation of MBHPP-polysters, the products usually contain some insoluble gel, which is probably caused by the crosslinking reaction of the vinyl groups of MBHPP in the aqueous NaOH. Thus, a modified interfacial polycondensation method was proposed, in which both of the bisphenol MBHPP and diacid chloride were dissolved in organic phase and then the solution was stirred with an aqueous NaOH solution to promote the polycondensation. This method reduced the time of MBHPP present in the alkali and produced polymers with higher inherent viscosity and lower gel fraction. The effects of some variables, such as the nature of porganic solvents and phase transfer agents and the concentration of reactants, on the modified interfacial polycondensation of MBHPP with the mixture of equal parts of isophthaloyl and terephthaloyl chloride [IPC/TPC (50/50)] were investigated in some detail. Copolyesters of mixed bisphenols of BPA/MBHPP with IPC/TPC (50/50) were also prepared and characterized.     

聚对苯二甲酸双酚丙烷酯的合成

聚酯的研究虽然早在1928年Carothers已开始进行,但是直到1941年Whinfield和Dickson发现聚对苯二甲酸乙二醇酯——涤纶——以后,才引起广泛的兴趣。由于大分子链中合有苯环,使绦纶具有高熔点和高结晶性,因而是一种优良的成纤材料。 如果继续增加主链中的苯环,可能得到热稳定性更高的高分子材料。本文郎报告聚对苯二甲酸双酚丙烷酯(Ⅰ)的合成和它的一些性能。KoptuaK等和Conix都会提到     

Polyarylates (I): Investigation of the interfacial polycondensation reaction by UV

The interfacial polycondensation of bisphenol A with isophthaloyl chloride and terephthaloyl chloride in dichloromethane with triethylbenzylammonium chloride as the catalyst was described. A well-defined two-phase system had been observed, so the concentration of bisphenolate in the aqueous phase could be determined by UV spectrometer. The conversion was found to increase rapidly with reaction time, but the rate of increase in molecular weight was slow. At the initial stage with conversion up to 95%, the reaction proceeded similarly to that of solution polycon-densation because the synthesized polyarylate could be dissolved in dichloromethane, and a polymer with a low molecular weight resulted. At the final stage of the reaction, the molecular weight was increased to a very high value due to the local concentration effect. The mole ratio of bisphenol A to diacid chlorides was found to affect the molecular weight very much. In the case of a mole ratio less than 1, the reaction remained in the initial stage mostly, and the molecular weight was low. However, for a mole ratio greater than 1, polyarylate with a very high molecular weight could be obtained because the local concentration effect was much more significant owing to the high concentration of bisphenolate that remained in the aqueous phase at the final stage.