简讯

中国石油吉化集团公司精细化学品厂高活性聚异丁烯催化剂配方和制备技术获国家专利由中国石油吉化集团公司精细化学品厂开发成功的"合成低分子量高活性聚异丁烯三氟化硼催化剂及其制备方法"目前获国家发明专利(专利号:ZL021 44631.8)。该项发明选用了苯烷基醚作为三氟化硼络合物催化剂的第三组合,制得的三氟化硼络合物催化剂,其稳定性有明显提高,可在0℃以下环境中保存更长时间。与现有技术相比,该发明使异丁烯转化率达到90%以上,分子量分布为1.8~2.5之间,端双键质量分数在90%~95%之间,生产的高活性聚异丁烯产品质量达到了国外同类产品的水…     

简讯

高活性聚异丁烯催化剂配方及其制备技术获国家专利由吉化集团公司精细化学品厂开发成功的“合成低分子量高活性聚异丁烯三氟化硼催化剂及其制备方法”目前获国家发明专利(专利号:zl021 44631.8)化剂,其稳定性有明显提高,可在0℃以下环境中保存更长时间。与现有技术相比,该发明使异丁烯转化率达到90%以上,分子量分布为1.8~2.5之间,端双键质量分数为90%~95%之间,生产的高活性聚异丁烯产品质量达到了国外同类产品的水平。该发明填补了国内空白,具有催化剂活性高、用量少、制备简单、使用安全等优点。(张晓君侯静波)Hexagon聚合物公司投资中国…     

反应器/塔耦合体系制备醋酸丁酯的研究

采用反应器/塔耦合体系,以纯醋酸和正丁醇为原料制备醋酸丁酯,借助Aspen Plus对酯化反应进行建模、模拟和优化.优化后产品醋酸丁酯的摩尔分数接近1.000,醋酸的转化率为0.987.将优化后的体系用于不同摩尔分数醋酸的回收,并对能耗进行了比较.结果表明,反应器/塔耦合体系可用于制备高纯度醋酸丁酯,也可用于回收不同摩尔分数的醋酸.醋酸的转化率随醋酸摩尔分数的提高而增大,能耗随醋酸摩尔分数的提高而降低.确定的操作条件可为实际的生产过程提供依据.     

我国低分子量聚异丁烯发展迅速

聚异丁烯（PIB）是异丁烯的均聚物，由于制备方法及工艺条件不同，聚异丁烯的分子量可在不同的范围内变化。低分子量聚异丁烯是一种化学性能稳定的非挥发性液体，在高温挥发或热分解后不会形成残留物，耐氧化，不透水蒸汽及其他气体，具有憎水性。低分子量聚异丁烯按α-末端双键含量还可分高活性聚异丁烯（HRPIB；HighlyReactivePolyisobutylene）和低活性聚异丁烯2种。高活性聚异丁烯其主要用途是用来生产聚异丁烯无灰分散剂（内燃机润滑油添加剂），调配二冲程油等；低活性聚异丁烯其主要用途是用来生产粘合剂、密封剂、电绝缘材料。     

我国高活性聚异丁烯的生产现状

高活性聚异丁烯(HRPIB;Highly Reactive-Polyisobutylene)是聚异丁烯α-末端双键含量大于80%的低分子量聚异丁烯,其主要特点是可以通过绿色环保的工艺生产出聚异丁烯无灰分散剂(内燃机润滑油添加剂),这种分散性能和低温性能俱佳且     

高效旋转精馏床的传质性能

以乙醇-水溶液为物系,以不锈钢波纹丝网为填料,在超重力因子为20~120、原料流量0.925~1.851 mol/h、回流比1.5~4.0、原料摩尔分数0.2425、室温进料和常压操作条件下,考察了高效旋转精馏床(HERDB)运行情况与传质性能。结果显示:①高效旋转精馏床运行平稳;②高效旋转精馏床的理论塔板数随超重力因子、原料流量和回流比的增大而增加;③在实验操作条件下,高效旋转精馏床传质单元高度为9.6~65.2 mm。与实验超重力精馏设备相比,高效旋转精馏床的等板高度大于实验室超重力精馏设备,说明存在放大效应。     

聚苯乙烯装置末段反应器更换前后产品性能的对比分析

对聚苯乙烯装置末段反应器更换前后产品性能进行了对比分析;末段反应器更换后聚合转化率上升,产品的残留单体和低聚物的质量分数下降,产品的相对分子质量分布变宽,加工稳定性增加。     

丁基橡胶聚合新型超重力反应器工艺

将新型旋转填充床反应器（RPB）应用于阳离子聚合制备丁基橡胶（IIR）过程。实验初步考察了旋转填充床转子转速（N）和聚合温度（T_p）等工艺参数对聚合产物IIR分子量和分子量分布的影响规律。研究结果表明：在实验条件下,当N=1200 r·min^-1、T_p=-100℃时,采用超重力法新工艺制备的IIR的数均分子量达到2.89×10⁵,分子量分布指数达到1.99。同时,物料停留时间小于1 s (现工艺30~60min),单位设备体积的生产效率提高了2~3个数量级。随着N的增大和T_p的降低,聚合产物IIR的分子量升高,而分子量分布变化不大。     

中国专利

<正>一种乙烯和α-烯烃共聚物的制备方法本发明公开的乙烯和α-烯烃共聚物的制备方法:在无水、无氧条件下,向釜式反应器内加入有机溶剂、α-烯烃共聚单体、助催化剂、主催化剂以及乙烯,反应温度和压力高于有机溶剂的超临界温度和超临界压力,主催化剂浓度为1.00~100.00μmol/L,助催化剂与主催化剂的摩尔比为(1.50~10 000.00)∶1.00,乙烯浓度为0.10~20.00 mol/L,α-烯烃与乙烯的摩尔比为(0.01~25.00)∶1.00,所有物料在反应器内停留时间控制在2~120     

甲烷化反应工艺流程和反应器模拟

通过分析绝热反应曲线和反应过程CO转化率曲线,设计可行的多级绝热固定床甲烷化工艺流程,得到了一个第一甲烷化反应器循环比为3.0,反应器个数为3的甲烷化反应系统。建立绝热固定床反应器的一维拟均相数学模型,在工业操作条件下,分析了该流程中3个甲烷化反应器内的温度和摩尔分数分布规律。在合成气的进料速度800 kmol/h,进料温度553 K,操作压力为3.0 MPa,氢碳物质的量比约为3.0,循环比为3.0的条件下,模拟结果表明:物料在3个反应器出口的温度分别为879,725,611 K;甲烷干基摩尔分数分别为53.48%,79.24%和95.49%;CO在3个反应器出口的转化率分别为82.18%,99.41%和100%。第3反应器出口CH4干基摩尔分数为95.49%,满足了工业生产要求。     

Shear,tack, and peel of polyisobutylene: Effect of molecular weight and molecular weight distribution

The effect of polymeric molecular weight and molecular weight distribution on pressure-sensitive adhesive performance was studied in a model system of commercial polyisobutylenes. Molecular weight was characterized by size exclusion chromatography and membrane osmometry. Pressure sensitive adhesive performance was assessed by shear, peel, and probe tack testing based on standardized test methods. Lower molecular weight polyisobutylenes (Mw < 600,000) are successful in peel and probe tack testing due to their ability to flow quickly and wet the substrate test surface. They do not function as well in shear, however, where the polymer must resist flow under a load. High molecular weight species, by contrast, perform well in shear resistance tests and less successfully in peel and probe tack testing. Where high and low molecular weight polyisobutylenes are blended to broaden the molecular weight distribution while maintaining constant weight average molecular weight, adhesive performance in shear, peel, and probe tack are improved. All of the adhesive properties tested were found to have their foundation in some fundamental rheological properties of the polymers (e.g., shear viscosity and tensile creep compliance). This suggests the use of fundamental rheological characterization for screening of adhesive formulations over more empirical adhesive testing methods.     

New telechelic polymers and sequential copolymers by polyfunctional initiator transfer agents (inifers)

Summary Three-arm star polyisobutylenes carrying tert.-chlorine end groups and a phenyl ring at the center of the star (see formula II in the Introduction) have been prepared by a continuous polymerization process. Thus into a stirred glass reactor were fed continuously a mixed feed of monomer plus trinifer (TCC) and a separate feed of BCl₃ coinitiator in methyl chloride solvent at –40°C, and the product plus unreacted ingredients were removed continuously. Stationary conditions were maintained by keeping the rates of input and output (i.e., volumes) equal and constant. After a short induction phase (2–3 residence times) telechelic polymers of essentially theoretical number average end functionalities (¯F_n=3.0+0.1), close to theoretical molecular weights (¯M_n) and molecular weight distributions were obtained. The polymerization kinetics are discussed and compared to that of an earlier semicontinuous process used for the routine synthesis of telechelic polyisobutylenes.     

Molecular weight distribution and rheological properties of polyisobutylene solutions

The molecular weight distribution of a series of polyisobutylenes was determined using osmotic pressure measurements, gel permeation chromatography, and intrinsic viscosity. All of the polymers except for one, a blend of the highest and lowest molecular weight constituents, had similar moderate molecular weight distributions. The “extended chain length” method of calibrating the gel permeation chromatograph for polyisobutylenes was found to be effective. Steady state and transient shear stresses and normal stresses were measured on 5% decalin solutions of these polymers. The zero shear viscosity increased with the 3.3 power of molecular weight, and the zero shear normal stress coefficient (σ₁₁ ? σ₂₂)/Γ² varied with the 7.5 power. Relative elastic memory as measured by (σ₁₁ ? σ₂₂)/σ₁₂ or stress relaxation increased with increasing molecular weight (and at constant number- or weight-average molecular weight) with breadth of distribution. Stress overshoot also correlated with this tendency.     

UV induced reversible chain extension of 1-(2-anthryl)-1-phenylethylene functionalized polyisobutylene

The synthesis of novel 1-(2-anthryl)-1-phenylethylene (APE) di-telechelic polyisobutylenes is described. Utilization of a difunctional cationic initiator and the in situ addition of the non-homopolymerizable APE lead to the formation of di-anthryl telechelic polyisobutylenes. Products were characterized by ¹H NMR spectroscopy and Size Exclusion Chromatography. The polymers were UV irradiated at 365 and 254 nm and the reversible photocycloaddition of anthryl moieties was investigated. The chain extension of di-anthryl telechelic PIBs through photocoupling at 365 nm produced higher molecular weight products from low molecular weight precursors. The effect of precursor polymer concentration on the degree of chain extension was investigated, and intermolecular interactions leading to the formation of tetramers was observed. The photocoupled products were UV irradiated at 254 nm to induce the reversal of photocycloaddition of anthryl groups and to follow the consequent photoscission of polymers.     

Surface tensions of liquid polyisobutylenes

Measurements of surface tensions were carried out in the temperature range 25–120°C on seven different liquid polyisobutylenes with molecular weights ranging from 100 to 80,000. Relationships between the surface tenstion of polyisobutylene and other properties, such as the parachor, cohesive-energy density, and molecular weight are discussed.     

Antimisting action of polymeric additives in jet fuels

Polymeric solutes in jet fuel can serve to increase greatly the droplet size and reduce flammability in fuel sprays created by high-velocity wind shear. Photographic and spark-ignition studies show that high molecular weight polyisobutylenes can be effective at levels below 100 ppm, where they cause only slight increases in fuel viscosity. The effectiveness of the polymers increases with molecular weight and is very well correlated by the elongational viscosity of the solution, as measured by the ductless siphon height.     

PIV技术测试聚合物流体拉伸流动的实验研究

针对低相对分子质量、低黏度的牛顿流体（如聚异丁烯）和非牛顿流体（如3 %苯甲酸钠溶液）,采用粒子成像速度仪（PIV）系统测试了2种流体在同一流率下流经渐变收缩流道时的速度分布,并研究比较了壁面处的纯剪切流动与流道中心轴线上的拉伸流动。通过实验测试与有限元模拟比较发现,牛顿流体和非牛顿流体的速度分布形态具有一定的差异。在确定速度分布的情况下,根据渐变收缩流动的特点,可以得到流体流动时中心轴线上的拉伸速率和边界处的剪切速率。     

Viscometric Behavior of Solution of Polyisobutylene in Hexane and Cyclohexane Solvents: Viscosity-Molecular Weight Relationships

The behavior of three different high molecular weight polyisobutylenes (PIB) in solutions of hexane and cyclohexane at 30°C has been investigated by viscometry. Mark–Houwink relations have been examined, the polymer–solvent interaction is discussed in terms of the calculated Huggins constant, k; parameter a of the Mark–Houwink equation; and equivalent hydrodynamic volumes V _e. The molecular weights of the three sample of polyisobutylene are remarkably well fitted with the intrinsic viscosity data.     

Living carbocationic polymerization of isobutylene by tert-amyl alcohol/BCl3/1-methyl-2-pyrrolidinone initiating system

1-Methyl-2-pyrrolidinone has been investigated, for the first time, as an efficient electronpair donor in conjunction with tert-amyl alcohol and BCl₃ in CH₂Cl₂ diluent at ?40°C for the living polymerization of isobutylene. The use of this new monofunctional initiator -trans fer (minifer) system has led to the synthesis of low molecular weight, living (near-monodisperse) polyisobutylenes carrying “ethyl” head group and “tert-chloro” end group (asymmetric telechelic polyisobutylenes). The nature of these groups was confirmed by ¹H-NMR spectroscopy. The living nature of the α-ethyl-ω-(tert-chloro)polyisobutylenes has been demonstrated by a linear plot, passing through the origin, of number-average molecular weight (M?_n) vs. the amount of polymer formed (W_p) and a horizontal N (number of polyisobutylene molecules) vs. W_p plot. These results are further substantiated by gel permeation chromatography data of these polymers, and the molecular weight distributions of these polymers are narrow (low M?_w/M?_n = 1.1–1.2). The initiating efficiencies (I_eff) are close to 100% with this system. Dehydrochlorination of the prepolymer has yielded an isopropylidene (exo-olefin) end group. Structure of the end group in the resulting polymer, α-ethyl-ω-(isopropenyl)polyisobutylene, was confirmed by FTIR spectroscopy.     

Head to head polymers

Blends of head to head polyisobutylene and amorphous head to tail polyisobutylene were prepared by casting films of the polymer mixtures from o-dichlorobenzene. The glass transition behavior of the polymer blends was studied by DSC analysis. Two glass transition temperatures were observed over almost the entire composition range which indicates that the two structurally similar head to tail and head to head polyisobutylenes are not miscible even in the molecular weight range of 3000 to 5000.