星形氢化无规共聚物HSSIBR的制备与表征

大连理工大学以二乙烯基苯(DVB)为偶联剂,环己烷为溶剂,通过阴离子聚合制备了星形苯乙烯-异戊二烯-丁二烯三元无规共聚物(SSIBR);以环烷酸镍和三异丁基铝作为催化剂,在60℃和4.0MPa氢压下反应4h,制备了氢化度为100%的氢化星形苯乙烯-异戊二烯-丁二烯三元无规共聚物(HSSIBR)。考察了DVB/Li用量、单臂相对分子质量对聚合物偶联效率(CE)和加氢反应     

HSD型润滑油黏度指数改进剂

介绍了国内润滑油对黏度指数改进剂的需求现状和PIB、PMA、OCP、HSD黏度指数改进剂的性能,重点介绍了氢化苯乙烯-双烯共聚物(HSD)的合成及其结构特点,指出研究开发HSD类黏度指数改进剂的是苯乙烯-丁二烯共聚物的又一应用方向。     

我国SEPS成套技术达国际领先水平

<正>氢化苯乙烯/异戊二烯共聚物(SEPS),是由苯乙烯和异戊二烯共聚物选择加氢生成。作为一种高性能高分子材料,氢化苯乙烯/异戊二烯共聚物主要应用领域为光纤光缆油膏、润滑油黏度指数改进剂,以及体育运动器械、防护用品、成人用品、线材膜材等用弹性体。其在光纤光缆油膏领域具有不可替代性,是性价比高的润滑油黏度指数改进剂,以及高回弹或低硬度的关键材料。据了     

二乙烯基苯异构体对聚二烯烃负离子活性链偶联反应的影响

采用负离子聚合法,以二烯烃类为单体、环己烷为溶剂、四氢呋喃为调节剂、n-BuLi为引发剂,用二乙烯基苯(DVB)混合物以及单独的对位或间位DVB(p-DVB、m-DVB)异构体为偶联剂合成星形聚合物。考察了偶联剂种类和用量、温度、单臂数均分子量以及单体种类对星形聚合物偶联效率、平均臂数的影响。结果表明,3种偶联剂的偶联效率由高到低依次为m-DVB、DVB混合物、p-DVB,m-DVB的偶联效率能达到92.0%;3种偶联剂得到聚合产物的平均臂数由多到少依次为p-DVB、DVB混合物、m-DVB;当温度为50℃时,聚合产物的偶联效率最高;偶联效率随偶联剂用量的增加而提高;单臂数均分子量的增大会使偶联效率降低;采用3种不同单体进行负离子聚合时,偶联效率按丁二烯、异戊二烯、丁二烯-苯乙烯的顺序依次降低。     

氢化苯乙烯-异戊二烯共聚物黏度指数改性剂的合成和性能

采用阴离子聚合法合成了三种氢化苯乙烯-异戊二烯共聚物,包括线形氢化苯乙烯-异戊二烯两嵌段共聚物(HSI)、氢化不对称长链高度支化型苯乙烯-异戊二烯嵌段共聚物[H S_m-I/Y_n]和核心多臂短直链型苯乙烯-异戊二烯嵌段共聚物[H(SI)_mY_n],并与三元乙丙橡胶(EPDM4045M)和壳牌公司聚苯乙烯-异戊二烯氢化物(SV-260)黏度指数改进剂(Ⅶ)的性能进行了对比,研究了其作为Ⅶ的增稠能力、剪切稳定性和黏温性能与聚合物结构和相对分子质量分布之间的对应关系。结果表明,H S_m-I/Y_n可与SV-260相媲美。     

星型SIBR合成中偶联反应的研究

以n-BuLi为引发剂,环乙烷为溶剂,SnCI4为偶联剂,在不同极性添加剂存在下合成了苯乙烯、异戊二烯和丁二烯的偶联星型无规共聚物SIBR。研究了聚合阶段不同极性添加剂（THF、THF－2G和2G)、偶联温度、偶联剂用量及偶联方式对偶联效果的影响。 研究结果表明适宜的工艺条件为：极性添加剂THF或THF－2G;偶联温度70℃;偶联剂用量n(SnCI4)/n(Li)=0.40-0.45(THF作极性添加剂）或0．35（THF－2G作极性添加剂）;二次偶联、偶联前加入适量极性添加剂及丁二烯戴帽,都可以提高偶联效果。     

星形异戊二烯-苯乙烯嵌段共聚物合成方法

中国石油大连润滑油研究开发中心采用阴离子聚合法,以正丁基锂为引发剂,先合成了线形异戊二烯-苯乙烯嵌段活性链;再以二乙烯基苯（DVB）为偶联剂,采用分次滴加法合成了星形异戊二烯-苯乙烯嵌段共聚物。     

锡偶联型集成橡胶S-SIBR的合成表征与性能的研究

以正丁基锂为引发剂、四氯化锡为偶联剂合成出了锡偶联型S－SIBR（溶液苯乙烯－异戊二烯－丁二烯共聚物）,用^1H-NMR,GPC及DSC等方法对共聚物微观结构、序列分布及相对分子质量分布等进行了表征分析,证明了聚合产物具有锡偶联结构,苯乙烯单元在聚合物链上呈无规分布。物理性能、疲劳性能及动态力学性能测试结果表明,S－SIBR物理性能满足胎面胶的基本要求,并且疲劳性能良好、滚动阻力低、抗湿滑性好。     

沥青改性用星线共混丁苯嵌段共聚物的合成研究

以环己烷、正己烷混合物为溶剂,四氢呋喃为结构调节剂,正丁基锂为引发剂,丁二烯、苯乙烯为单体,采用双官能团线型偶联剂及四臂星型偶联剂,以阴离子两步法偶联工艺合成了沥青改性用苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）。结果表明：采用星线化学共混偶联所合成的样品GPC谱图呈三峰分布特征,可获得理想的沥青改性效果,尤其是可以实现改性沥青2个重要指标的平衡统一。     

环氧化液体丁二烯-苯乙烯共聚物的制备

采用阴离子聚合制备了线型和星型液体丁二烯-苯乙烯嵌段共聚物(LBSC)、含渐变段共聚物和无规共聚物。采用甲酸-H_2O_2原位法对上述LBSC进行了环氧化反应。考察了H_2O_2用量、环氧化反应时间和温度、相对分子质量、苯乙烯含量和序列结构等对LBSC环氧化反应的影响;研究了环氧化液体丁苯共聚物(ELBSC)偶联剂对聚丁二烯活性链末端偶联反应的影响。结果表明:控制H_2O_2用量可以得到环氧值可控的ELBSC,当H_2O_2与丁苯共聚物中聚丁二烯双键的摩尔比为0.6,反应时间在120 min,温度在50℃时可达到最大环氧值;随着ELBSC用量的增加,偶联效率逐渐增大,相对臂数逐渐减小,在环氧基团与锂的摩尔比为1.0时偶联效率最大。     

星形杂臂异戊二烯-丁二烯-苯乙烯橡胶的结构与性能

采用负离子溶液聚合法,以正丁基锂为引发剂、环己烷为溶剂、十二烷基苯磺酸钠/四甲基乙二胺为复合结构调节剂、二乙烯基苯为偶联剂制备了具有高抗湿滑性和低滚动阻力的星形杂臂异戊二烯-丁二烯-苯乙烯橡胶,考察了聚合温度及结构调节剂和偶联剂用量对聚合物微观结构、动态力学性能及力学性能的影响.结果表明,聚合物中非1,4-结构链节的含...     

星形杂臂橡胶S-(PB)_n-(PSB)_n的合成与性能研究

采用溶液聚合法,以环己烷为溶剂、以THF为结构调节剂、以DVB为偶联剂,制备了星形杂臂橡胶S-(PB)n-(PSB)n。主要研究了苯乙烯含量、偶联效率等对物理机械性能及加工性能的影响。结果表明,随着苯乙烯含量的增加,抗湿滑性能得到提高。随着偶联效率的增加,断裂伸长率\拉伸强度和门尼粘度都增加,撕裂强度基本不变,而硬度有降低的趋势。星形杂臂橡胶S-(PB)n-(PSB)n的门尼粘度(ML1+4100℃)可达到70,断裂伸长率>470%,拉伸强度>21 MPa,0℃的tanδ值达到0.27,60℃的tanδ值可达到0.09,是一种兼具良好的抗湿滑性能和低的滚动阻力的新型胎面胶材料。     

Polymeric additives for improving the flow properties and viscosity index of lubricating oils

Four sets of copolymeric additives were synthesized via copolymerization of dialkyl fumarates and dialkyl maleates with vinyl acetate (VAc) and vinylpyrrolidone (VP) monomers. The dialkyl esters were prepared by the esterification of maleic and fumaric acids with a series of n-alkanol having an increasing number of carbon atoms to produce two groups of diesters. The completion of the esterification reaction was confirmed by spectroscopic analysis. The molecular weights of the prepared esters and copolymers were determined and the influences of different parameters on the molecular weight of the produced copolymers were discussed. The efficiency of the prepared copolymers as viscosity index and flow improvers (pour point depressants) was investigated. It has been found that the dialkyl ester/VP copolymers are more efficient as viscosity index improvers than the dialkyl ester/VAc copolymers. On the other hand, it has been found that the copolymers based on didodecyl fumarate/VAc are the most effective pour point depressants.     

Emulsion-based pressure sensitive adhesives from conjugated linoleic acid/styrene/butyl acrylate terpolymers

Free radical emulsion terpolymerizations of conjugated linoleic acid (CLA), styrene (Sty), and butyl acrylate (BA) were performed at 80 °C. Terpolymers were characterized for composition, conversion, molecular weight and glass transition temperature, latexes were characterized for viscosity and particle size while adhesives were characterized for tack, peel strength, shear strength, storage modulus, loss modulus and tan delta. One impurity commonly found in CLA, oleic acid, was shown to influence the reaction kinetics significantly. Adhesive performance was tuned using divinylbenzene (DVB) crosslinker to keep the terpolymer molecular weight in a desired range. By using a constrained mixture design, the influence of terpolymer composition, chain transfer agent (CTA) concentration, DVB concentration, molecular weights, viscosity and particle size on tack, peel strength and shear strength was investigated. The final forms of the resulting empirical models allowed the creation of 3D response surfaces for pressure sensitive adhesive (PSA) performance optimization.     

Effect of wax inhibitors on pour point and rheological properties of Iranian waxy crude oil

A variety of techniques have been employed in order to reduce problems caused by the crystallization of paraffin during the production and/or transportation of waxy crude oil. Flow improvers are used extensively to increase the mobility of crude oil. In this study, the influence of the ethylene-vinyl acetate copolymer (EVA), as flow improver, with different ranges of molecular weight on the viscosity and pour point of five Iranian waxy crude oils was evaluated. Five types of Iranian waxy crude oil were selected based on their similar wax (> 10%) but different asphaltene contents. Also, the effect of asphaltene content on the performance of this flow improver was studied. The rheological behavior of these crude oils, with middle range API gravity, in the absence/presence of flow improver was studied. The rheological data cover the temperature range of 5 to 40 °C. The results indicated that the performance of flow improver was dependent on the molecular weight and the asphaltene content. For crude oil with low asphaltene, higher molecular weight flow improvers are the best additive and lower molecular weight flow improvers showed good efficiency for crude oil with high asphaltene content. Addition of small quantities of asphaltene solvents such as xylene (1 wt.%), alone or in combination with flow improver, can improve viscosity of crude oil with high asphaltene content.     

Molgewichtsverteilung und Langkettenverzweigung bei der anionischen Polymerisation von Butadien

The copolymerization of butadien with small amounts of divinyl benzene (DVB) has been investigated. The polymerization has been carried out with a lithiumamide as initiator in n-hexane as solvent under addition of tetrahydrofuran (THF) to govern the content of vinyl groups. By gel permeation chromatography coupled with a viscometer the molecular weight distribution (MWD) and long chain branching as a function of the conversion and of the molecular weight have been determined. Using a differential refractometer and a UV-photometer as detectors the distribution of the branching agent DVB vs. molecular weight has been studied. With our example long chain branching decreases with increasing conversion. The insertion of DVB occurs mainly in the first phase of the reaction. With increasing conversion the MWD becomes broader. At very high degrees of conversion the molecular weight increases considerably by coupling reactions.     

聚碳硅烷/二乙烯基苯粘度特性研究

通过粘度实验,研究了20～140℃温度范围内浸渍用聚碳硅烷(PCS)/二乙烯基苯(DVB)体系流变学性质。PCS在DVB中以溶解和熔融的方式分散,温度为影响体系粘度的关键因素。结果表明PCS/DVB体系在80～120℃的温度范围内,粘度低于300mPa·s,可满足浸渍要求。     

微波液化木材及聚醚多元醇的制备

以醇解的聚酯(PET)饮料瓶为液化剂,甘油作辅助液化剂,微波辅助加热,用2.5%H2SO4催化液化木材。分别讨论了微波功率、液固比/反应时间和温度对液化率的影响。结果表明,在微波功率500 W,反应时间15 m in,温度150℃,液固比为4的条件下,木材液化率99.16%。以此液化物为起始剂,选用双金属氰化物MMC催化环氧丙烷开环聚合,通过改变环氧丙烷的用量制备了不同聚醚多元醇,并采用傅里叶变换红外(FT-IR)、凝胶色谱(GPC)及热示差扫描(DSC)等分析手段对起始剂和不同聚醚多元醇的结构、分子质量分布和耐热性进行了对比表征。研究表明聚醚多元醇的羟值、酸值、黏度随环氧丙烷用量增加减小,分子质量分布随之变窄,热稳定性下降。     

High-viscosity index lubricating oils from EPR destruction products

Polyolefinic oils obtained from olefin oligomerization or copolymerization involve the most common synthetic hydrocarbon oils. Research and experimental results concerning high viscosity index synthetic polyolefinic oils and viscosity index improvers' production by ethylene–propylene copolymer (EPR) and thermal destruction of EPRs noted for various molecular weight and composition resulted in high viscosity index polyolefinic oils and thickeners. The effect of structure, composition, and molecular weight on the destruction process has been discussed for various EPRs. The resulting polyolefinic oils and viscosity index improvers were studied. © 1992 John Wiley & Sons, Inc.     

原子转移自由基偶联法合成星形聚合物

以卤端基聚合物为大分子引发剂,卤化亚铜／２,２‘＝二联二吡啶为催化剂,工业二乙烯基苯、纯间－二乙烯基苯、纯对－二乙烯基苯为偶联剂合成了一系列星形聚合物。研究了偶联反应的影响因素。结果表明,反应体系产生凝胶的趋势随着二乙烯基苯与预聚物配比的增加而增加;偶联反应速度随着反应物总浓度的增加而加大;提高反应温度有利于提高偶联效率;以低单体转化率下合成的预聚物为大分子引发剂时的偶联效率高于高单体转化率下合成