用二苯醚改性钛系催化剂制备异戊橡胶

用二苯醚改性钛系催化剂合成了异戊橡胶,讨论了催化剂各组分加料顺序对单体转化率、产物凝胶含量和相对分子质量的影响.结果表明,当催化剂三组分以等摩尔比加入时,所得产物主要为顺式结构,顺式摩尔分数约为95%.采用(三异丁基铝-二苯醚)-四氯化钛络合方式时,三异丁基铝/四氯化钛(摩尔比,下同)为0.8时活性最高.三组分单独加入反应体系时,二苯醚/三异丁基铝为0.4左右时转化率最高.用二苯醚的两种不同络合方式所得催化剂聚合产物的凝胶含量明显低于未添加二苯醚者,其中采用(三异丁基铝-二苯醚)-四氯化钛络合方式催化体系所得产物的特性黏数明显大于另外两种.     

负载钛催化异戊二烯本体沉淀聚合动力学的研究

采用负载钛催化剂,在０￣３０℃下对异戊二烯（Ｉｐ）本体沉淀聚合的动力学进行了研究。结果表明,体系在单体相未消失之前为稳态聚合,其稳态聚合速率方程为：Ｒｐ＝ｋｐｆ［Ｔｉ］０［Ａｌ］０［Ｍ］０,即在单体相未消失前,Ｒｐ为恒量。计算出Ｉｐ本体沉淀聚合的表观活化能为２９．７ｋＪ／ｍｏｌ,催化剂利用率为２０％￣３０％,高于溶液聚合法。     

Indene polymerization under the action of titanium tetrachloride

The cationic polymerization of indene under the action of TiCl₄ is considered, in the presence of toluene. The reaction is greatly affected by the competition between the solvent and the monomer in TiCl₄ solvation. Active centers are formed on account of the direct addition of TiCl₄ by the vinyl bond of the monomer. In the given system, polymerization is most likely due to chain growth at the contact pairs or solvationally separated ion pairs. Effective values of the rate constants of catalyst solvation and chain growth are calculated.     

Ethylene polymerization with high activity catalysts prepared from titanium tetrachloride and magnesium diene adducts

Magnesium (isoprene)₂ adducts were prepared in THF and transferred to toluene solutions. The products from the reaction of these solutions with TiCl₄ gave highly active catalysts for ethylene polymerization when used with aluminium trialkyl co-catalysts. Results of polymerizations under various conditions are given. Comparison experiments were carried out with catalysts prepared from magnesium myrcene and magnesium diphenyl butadiene adducts. Reaction products of TiCl₄ and magnesium diene mixtures were separated into soluble and insoluble fractions and analysed.     

Effects of amines on the polymerization of isoprene with sec-butyllithium catalyst

Polymerization of isoprene (IP) with alkyllithium (RLi) catalysts in the presence of amines such as triethylamine (TEA), 1,2-dipiperidinoethane (DPPE) and N,N,N′,N′-tetramethyldiaminoalkanes [(CH₃)₂N(CH₂)_nN(CH₃)₂ where n=1, 2, 3, 4 and 6 (TMDAA)] has been studied. By adding the amines, the polymerization rate of IP was accelerated, and the contents of 3,4- and 1,2-units in the resulting polymers increased. The effects of methylene chain length of the TMDAA on the polymerization were examined. It was found that both the polymerization rates and the microstructure of the polymers depend on the methylene length of the TMDAA. The amines having 2 and 3 methylenes in (CH₃)₂N(CH₂)_nN(CH₃)₂ favoured production of the polymer consisting of predominantly 1,2- and 3,4-units. It was proposed that two types of active sites for the polymerization of IP were produced depending on the number n of the TMDAA. Two types of active species were confirmed to be produced with sec-BuLi in the presence of N,N,N′,N′-tetramethylethylenediamine (TMEDA) depending on the TMEDA/sec-BuLi mole ratios. © 1998 SCI.     

甲基铝氧烷对稀土催化体系催化异戊二烯聚合的影响

考察了甲基铝氧烷(MAO)作为助催化剂对稀土催化体系催化异戊二烯聚合的影响,结果表明MAO可极大地提高体系的催化活性,获得顺-1,4结构含量95%(质量分数)以上的聚异戊二烯,并且调节n(MAO)/n(Nd)和n(Al)/n(Nd)的值可有效地提高聚合产物的相对分子质量.     

钴系催化剂催化异戊二烯的本体聚合

以环烷酸钴(简称Co)-三异丁基铝(简称Al)-CS2为催化剂引发异戊二烯(Ip)本体聚合合成了聚异戊二烯(PI),考察了单体转化率、催化剂效率(CE)和聚合物特性黏数([η])的影响因素,并对PI的微观结构和玻璃化转变温度(Tg)进行了表征。结果表明,在Co/Ip(摩尔比)为4.0×10-4、Al/Co(摩尔比)为60、CS2/Co(摩尔比)为15、反应温度为50℃下聚合48 h所得PI中1,4-结构、3,4-结构、1,2-结构质量分数分别为18.6%,41.2%,40.2%,Tg为-6.5℃;反应温度对PI的[η]影响最大,随着反应温度的升高,[η]呈下降趋势,且均小于1 dL/g;其他聚合条件的变化对PI的[η]影响不大。     

Living cationic polymerization of isobutyl vinyl ether by the diphenyl phosphate/zinc iodide initiating system

Summary The first example of the living cationic polymerization of isobutyl vinyl ether via the phosphate counteranion has been achieved in toluene below 0°C with a new initiating system that consists of diphenyl phosphate and zinc iodide, (C₆H₅0)₂P(0)0H/ZnI₂. The number-average molecular weight of the polymers increased in direct proportion to monomer conversion, and was in excellent agreement with the calculated value assuming that one polymer chain forms per unit diphenyl phosphate. On addition of a fresh feed of monomer at the end of the polymerization, the added feed was smoothly polymerized at nearly the same rate as in the first stage, and the polymer molecular weight further increased in direct proportion to monomer conversion. Throughout the reaction, the molecular weight distribution of the polymers stayed very narrow (¯M/¯M_n 1.1). At room temperature (+25 °C), however, the molecular weight distribution of the polymers slightly broadened (¯M_w/¯M_n 1.2) at high conversions where the polymer molecular weight became smaller than the calculated value. Evidently, the (C₆H₅0)₂-P(0)0H/ZnI₂ system indeed generates a propagating species of a long life-time at room temperature, but the perfectly living polymerization by this system operates below 0°C.Living cationic polymerization of vinyl ethers by electrophile     

含三氟甲基二苯醚类除草剂的合成

本文讨论了含三氟甲基二苯醚类除草剂的合成方法，简要介绍了合成工艺，包括的品种有：三氟羧草醚、氟磺胺草醚、乙羧氟草醚、乳氟禾草灵，并提出了今后的改进方向。     

不同陈化方式对钼系催化异戊二烯聚合的影响

以辛醇取代的五氯化钼(简称Mo)、间甲酚铝(简称A1)为催化体系,以异戊二烯(Ip)为原料,磷酸三丁酯(TBP)为第3组分制备聚异戊二烯.在25℃下陈化0.5 h,探索分别以Al-Mo、Mo-TBP、Al-Mo-TBP、Al-Mo-TBP-Ip为陈化方式对Ip聚合活性及聚合物特性黏数的影响.结果表明,采用Al—Mo—T...     

四氯化钛生产工艺探讨

四氯化钛是钛及其化合物生产过程中的重要中间产品,是钛工业生产的重要原料。四氯化钛用于海绵钛、珠光染料、钛酸脂系列、钛白及烯烃类化合物的催化剂等,在中国已进行较大规模的生产。主要探讨了沸腾氯化 生产工艺和设备上存在的问题,对比了中国与美国、日本等发达国家技术上的差异。研究了原料特性、杂质含量对生产及设备的影响,介绍了生产中需要改进的地方以及今后发展方向。     

钛酸丁酯/负载钛体系催化异戊二烯聚合

以钛酸丁酯[Ti(C_4H_9O)_4] 和TiCl_4/MgCl2(简称Ti)为主催化剂、三异丁基铝(简称Al)为助催化剂催化异戊二烯 (Ip)聚合,考察了Ti(C4H9O)4和Al用量对聚合物在汽油中可溶性及单体转化率、催化效率(CE)的影响,并对聚合物进行了表征.结果表明,当Ti/Ip(摩尔比)一定时,聚合物在汽油中的溶解度随着Ti(C_4H_9O)_4/Ip(摩尔比)的增加而增大,Ti(C_4H_9O)_4/Ip为3×10~(-3)时,单体转化率达到最大值;当主催化剂配比及用量一定时,聚合物在汽油中的溶解度随着Al/Ti(C_4H_9O)_4(摩尔比)的增加先增大后减小,当 Al/Ti(C_4H_9O)_4为10～15时,单体转化率和CE存在最大值;该催化体系制得的聚异戊二烯以反式-1,4-结构为主,同时包含一定量的3,4-和1,2-结构.     

四氯化钛在天然生漆膜表面的化学修饰

通过四氯化钛和生漆膜的化学反应,在天然生漆膜表面形成一层修饰层。用红外光谱、X-射线能量色散光谱和扫描电子显微镜等,对该修饰层进行测试表征。结果表明漆膜易与四氯化钛发生化学反应并生成漆酚钛聚合物,反应后金属氧化物含量达10.76%,X-射线能量色散光谱(EDS)分析证明,反应主要在漆膜表面进行。     

Ring opening metathesis polymerization of dicyclopentadiene catalyzed by titanium tetrachloride adduct complexes with nitrogen‐containing ligands

Ring opening metathesis polymerization (ROMP) of dicyclopentadiene (DCPD) catalyzed by titanium tetrachloride adduct complexes such as TiCl₄ · 2L [L = pyridine (1), 2‐methylpyridine (2), 2,4,6‐trimethylpyridine (3), 3‐aminopyridine (4), 2‐hyroxypyridine (5)] and CH₃Li as cocatalyst was reported. The polymer was characterized by IR and ¹H‐NMR methods. Five influencing factors were also discussed. The catalyst systems TiCl₄ · 2L/CH₃Li (L = 2‐methylpyridine, 2,4,6‐trimethylpyridine) appeared to be very active for the ROMP of DCPD. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 3247–3251, 2000     

间甲基苯酚钾为调节剂的异戊二烯负离子聚合反应

考察了间甲基苯酚钾(m-ROK)用量对正丁基锂(n—BuLi)／m—ROK／二乙二醇二甲醚／异戊二烯／二甲苯负离子聚合体系的链转移反应、聚异戊二烯相对分子质量及微观结构的影响。结果表明,当m—ROK／n—BuLi(摩尔比)小于0．5时,聚异戊二烯的特性黏数和相对分子质量迅速下降,链转移次数增加;当m—ROK／n—BuLi(摩尔比)大于0．5时,则不遵循此变化规律。m—ROK的加入明显加宽了聚异戊二烯的相对分子质量分布。增加m—ROK用量时,聚异戊二烯微观结构中1,2-结构和3,4-结构质量分数下降,1,4-结构质量分数增加。     

The reaction engineering of the anionic polymerization of isoprene

The anionic solution polymerization of isoprene with n-butyllithium (n-BuLi) initiator and tetramethylethylenediame (TMEDA) modifier or n-butyllithium (n-BuLi)initiator and tripiperidinophosphine (TPPO) modifier was studied and kinetic and reactor models are proposed for both systems. Reactor conversion, molecular weight distribution, and polymer glass transition temperature had been calculated from the model and compared favorably to actual data for various combinations of reactor system and operating conditions. Simulations of the models can be used to design reactor systems, and predict polymer properties of a large-scale operation from results of small-scale batch reactor runs. © 1993 John Wiley & Sons, Inc.     

正辛醇改性负载钛催化体系聚合异戊二烯

以正辛醇改性TiCl4/MgCl2催化剂,将其用于异戊二烯聚合以期制得综合性能较为优异的3,4-聚异戊二烯／反式-1,4-聚异戊二烯(3,4-PIp／TPI)新型复合材料。当n(Al)／n(Ti)为10-20,催化剂和异戊二烯的摩尔比为1×10-4,聚合温度为60℃时,改性催化剂催化异戊二烯效率最高;改性催化剂(正辛醇和催化剂摩尔比为15)聚合所得聚异戊二烯中3,4-链节的质量分数达45．01％,聚合产物的熔点及结晶度均低于传统的TPI。     

正辛醇改性负载钛催化体系催化异戊二烯聚合的研究

以不同用量正辛醇改性负载钛催化体系(TiCl4/MgCl2)催化异戊二烯配位聚合,考察了催化剂用量、Al剂用量及反应温度对聚合的影响,通过1H-NMR法表征了聚合产物的微观结构,通过DSC表征了聚合产物的熔点及结晶度。结果表明:改性负载钛催化体系的催化效率随正辛醇用量的增大而降低,当聚合条件为n(Al)/n(Ti)=50,n(Ti)/n(Ip)=5×10-4,聚合温度60℃时,催化效率最高。聚合产物的相对分子质量随正辛醇用量的提高而增大、随主催化剂用量的提高而降低,Al剂用量及反应条件对聚合物相对分子质量的影响同对催化活性的影响基本一致。所得聚异戊二烯的3,4-结构质量分数为8.2%,反-1,4-结构质量分数为91.8%;聚合产物的熔点及结晶度均低于TPI。     

烷基二苯醚二磺酸盐的性能与应用

烷基二苯醚二磺酸盐是最早实现工业化的双亲水基Gemini型表面活性剂，由于其独特的双磺酸盐结构。具有许多优异的性能。介绍了烷基二苯醚二磺酸盐的物理及化学性质．及其合成、生产、应用及技术进展情况。     

CCl4低温氯化人造金红石制备TiCl4

为了开发低温钛氯化工艺及解决工业副产物CCl₄的再利用问题,在固定床和流化床反应器中考察了自贡法人造金红石原料与CCl₄低温氯化制备TiCl₄的反应过程,利用SEM、XRD、XPS等手段表征了人造金红石原料在反应前后的变化。结果显示,在450～500℃下,自贡法人造金红石能与CCl₄快速反应生成TiCl₄产品。少量Fe元素的掺杂是金红石相具备较高反应速率的关键原因。人造金红石原料制备过程中的弱氧化焙烧处理在颗粒表面形成的惰性金红石壳层,导致TiCl₄收率极限为90%,但该壳层能在酸解过程以及低温CCl₄氯化过程中维持颗粒粒度,使该原料能用于流化床操作。此过程具有显著的环保价值和工业应用前景。