新癸酸钕-三辛基铝-叔丁基氯催化体系合成高顺式聚异戊二烯

以新癸酸钕(简称Nd)-三辛基铝(简称Al)-叔丁基氯(简称Cl)为催化剂合成了聚异戊二烯(IR),考察了催化剂的配制顺序、陈化温度和时间、陈化方式、组分比、聚合温度对聚合活性和IR微观结构的影响,并与传统催化剂Nd-三异丁基铝-倍半乙基氯化铝合成的IR结构与性能进行了比较.结果表明,催化剂采用Nd和Al先混合30 m...     

异戊橡胶稀土催化剂用量与转化率之间的关系

选用新癸酸钕-三异丁基铝-倍半乙基氯化铝络合体系的稀土催化剂,配制不同活性的催化剂,在实验室进行瓶聚合后,投入生产参加聚合反应,得到催化剂用量和聚合转化率之间的函数关系。实验和生产得到的结论相互校正。摸索在门尼调整过程中维持高转化率状态。     

钒系催化体系提高三元乙丙橡胶ENB转化率

通过用现装置上在用的钒催化剂对乙烯、丙烯、乙叉降冰片烯(ENB)三元共聚合条件的实验,确定了聚合温度及压力的改变对ENB的转化率没有影响;适当降低聚合单体的体积流量可以提高ENB的转化率;以大配体的二(磷酸二异辛酯基)氧钒络合物为主催化剂,以乙基倍半氯化铝(AQ)为助催化剂,乙烯、丙烯为聚合单体,ENB为第三单体,己烷为聚合溶剂,通过溶液聚合合成了乙烯、丙烯、ENB三元共聚物,其中ENB的转化率明显高于装置上现用的小配体的钒催化剂。     

聚丁二烯/烯丙基异丁基多面体低聚倍半硅氧烷纳米杂化材料的形貌及性能

对采用活性负离子聚合法制得的聚丁二烯( PB)/烯丙基异丁基多面体低聚倍半硅氧烷(A - POSS)纳米杂化材料进行硫化,采用X射线衍射仪、扫描电子显微镜、差示扫描量热法、热重分析、动态力学性能分析等手段,研究了A - POSS含量对硫化PB/A -POSS纳米杂化材料的微观形貌、耐热性能和动态力学性能的影响.结果表明...     

双环戊二烯聚合初始动力学的研究

对双环戊二烯聚合生成聚双环戊二烯的前期动力学进行了研究。采用的催化体系由五氯化钼和二乙基氯化铝组成,溶剂为正己烷。根据金属-碳烯活性中心引发的链式开环聚合机理确定了双环戊二烯开环聚合的动力学方程,采用多元非线性回归（Pow-ell法）拟合,得到有关参数。     

用钛酸丁酯复合钛催化体系引发异戊二烯聚合 Ⅰ.聚合条件的影响

以钛酸丁酯和负载钛(TiCl4/MgCl2)为主催化剂、三乙基铝为助催化剂催化异戊二烯聚合,研究了主催化剂用量、三乙基铝与钛酸丁酯的摩尔比、负载钛催化剂加入时间及温度等对单体转化率和催化效率的影响,并对聚合物的汽油不溶部分和可溶部分的结构进行了核磁共振氢谱表征,用差示扫描量热法测试了汽油不溶部分的结晶度.结果表明,所得聚合产物为1,4-结构摩尔分数67.4%、3,4-结构摩尔分数32.6%的复合异戊橡胶;聚合体系的单体转化率随钛酸丁酯/异戊二烯(摩尔比,下同)的增大而升高,而催化效率则先升高后降低;二者均随三乙基铝/钛酸丁酯的增大先升高后降低,最佳值为9～10;二者均随加入二种催化剂时间间隔的延长先升高后降低,随聚合温度的升高先升高后降低,且在30～35 ℃时达到最高值.     

异丁烯-对甲基苯乙烯无规共聚物的合成与表征

以二枯基氯/四氯化钛/2,6 -二叔丁基吡啶为引发体系,在-80℃条件下采用正离子聚合法合成了异丁烯-对甲基苯乙烯无规共聚物(IB -co -p - MeSt),研究了不同单体投料比(摩尔比)下聚合反应的特征,并通过示差折光指数仪/多角激光光散射仪/紫外检测器、核磁共振氢谱、差示扫描量热法和热重分析对无规共聚物进行了表...     

丙酮作为引发体系的第3组分对溶液法合成丁基橡胶的影响

以丙酮作为引发体系的第3组分,采用溶液法合成丁基橡胶,研究了丙酮对聚合的影响。结果表明,丙酮对正离子活性中心具有一定的抑制作用,并能在反应后期减少副反应的发生,进而提高聚合产物的相对分子质量。当乙基倍半铝氯化物、水及丙酮的摩尔比为14.1/1/0.90时,可在较高的温度下制得相对分子质量较高且分子量分布较窄的聚合物。     

烯丙基异丁基多面体低聚倍半硅氧烷/聚丁二烯遥爪型纳米杂化材料的制备及表征

采用负离子聚合法,以单官能团笼型烯丙基异丁基多面体低聚倍半硅氧烷(POSS)和丁二烯为单体、正丁基锂为引发剂、环己烷为溶剂及乙基四氢糠基醚为调节剂,制备了烯丙基异丁基POSS/聚丁二烯遥爪型纳米杂化材料,对其结构进行了表征.结果表明,POSS与丁二烯发生了共聚合,实现了活性负离子引发聚合制备POSS/聚丁二烯遥爪型纳米...     

环氧树脂/倍半硅氧烷共混材料的性能研究

通过三烷氧基硅烷水解缩聚反应制备了甲基倍半硅氧烷(MSSQ)单体和乙基倍半硅氧烷(ESSQ)单体,采用红外光谱、核磁共振、元素分析对其进行表征,证实了倍半硅氧烷(SSQ)的立体结构。采用共混法制备了环氧树脂(EP)/SSQ和EP/纳米SiO2共混材料,性能测试结果表明,相对于纯EP及EP/纳米SiO2共混材料,EP/SSQ共混材料具有较高的玻璃化转变温度、热变形温度、热稳定性及力学性能。     

Cationic polymerization in rotating packed bed reactor: Experimental and modeling

On the basis of analysis of key engineering factors predominating in cationic polymerization, butyl rubber (IIR) as an example was synthesized by cationic polymerization in the high‐gravity environment generated by a rotating packed bed (RPB) reactor. The influence of the rotating speed, packing thickness, and polymerization temperature on the number average molecular weight (M_n) of IIR was studied. The optimum experimental conditions were determined as rotating speed of 1200 r min^?1, packing thickness of 40 mm and polymerization temperature of 173 K, where IIR with M_n of 289,000 and unimodal molecular weight distribution of 1.99 was obtained. According to the experimental results and elementary reactions, a model for the prediction of M_n was developed, and the validity of the model was confirmed by the fact that most of the predicted M_ns agreed well with the experimental data with a deviation within 10%. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

Grafting of butyl acrylate and methyl methacrylate on butyl rubber using electron beam radiation

Being nonpolar in nature, butyl rubber (IIR) has poor compatibility toward polar polymers and fillers. It can be improved by grafting polar substrates on the butyl elastomer. Radiation‐induced polymer processing is getting increasing interest, as it leads to new and improved polymers with desirable and interesting properties. In this investigation, electron beam radiation has been used to graft methyl methacrylate (MMA) and butyl acrylate (BA) on IIR. This process has several advantages over conventional grafting processes such as cationic polymerization (which needs very low temperature and stringent reaction conditions) and solution radical polymerization (which often needs solvent removal and recycling). The grafted polymers were characterized by using ¹H NMR, IR, TGA, and SEM analysis. The degree of grafting increases with a decrease in irradiation dose as well as with an increase in monomer concentration. It was observed that there was a decrease in intrinsic viscosity in irradiated IIR samples, indicating the chain scission. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1340–1346, 2006     

高性能丁基橡胶/有机黏土纳米复合材料的新型制备方法

采用一种新型制备方法--预膨胀有机黏土与机械共混的方法制备丁基橡胶（IIR）/有机黏土纳米复合材料。实验结果表明,当有机黏土为10 phr时,采用预膨胀有机黏土（S-OC）与机械共混的方法制备的IIR/有机黏土纳米复合材料（IIR/S-OCNs）的拉伸强度和撕裂强度,明显优于采用熔体法制备的IIR/有机黏土（OC）纳米复合材料（IIR/OCNs）的相应性能,较纯丁基橡胶分别提高了4.96倍、0.22倍;当有机黏土为5 phr时,采用预膨胀有机黏土与机械共混的方法制备的IIR/S-OC纳米复合材料的气体渗透率,分别较纯IIR、熔体法制备的IIR/OC纳米复合材料下降了21.88%和12.50%。这种新型制备方法是将溶液制备方法的优点与熔体制备方法的优点有机地统一在了一起。该材料有可能在高级无内胎轮胎气密层以及其他要求高性能弹性体材料的领域获得应用。     

国内外丁基橡胶制备技术进展

介绍了国内外丁基橡胶的制备技术进展及新产品，近十年来，丁基橡胶（IIR）生产技术主要朝着改进淤浆及溶液聚合工艺，使用茂金属等新型催化剂，使用管束式新型聚合反应釜，使含卤单体参与共聚合直接制 备卤化IIR，用于蒸气清洗分子筛，在抗氧剂存在下聚合，在线预测IIR的不饱和度，用碘指数法和环氧滴定法测定IIR产品的不饱和度以及对IIR进行接枝和离子化化学改性等方向发展，出现了聚氧化乙烯接枝改性卤化IIR，星形支化型IIR，异丁烯／对甲基苯乙烯共聚物及其丙烯酸酯改性或卤化品种和高粘度IIR等新产品。     

Preparation and properties of dynamically vulcanised blends of isobutylene–isoprene rubber and isotactic polypropylene

Abstract

Dynamic vulcanisation was employed to prepare blends of isobutylene–isoprene rubber (IIR) and isotactic polypropylene (iPP) with superior properties. The preparation technology, the effects of the presence of IIR on the crystallisation properties of iPP and the mechanical properties of the IIR/iPP thermoplastic vulcanisates (TPVs) were investigated. It was revealed that, under regular shearing at 180°C, dynamic vulcanisation for 10 min produced IIR/iPP TPVs of excellent properties; while degradation occurred when the duration of vulcanisation was extended to 15 min. Incorporation of IIR into iPP dramatically reduced the size of the iPP spherulites, and thus decreased the melting temperature and the degree of crystallinity of the iPP. When the IIR content was 50 wt-%, maximally balanced mechanical properties of IIR/iPP TPVs were obtained with a Charpy impact strength of 53·6 kJ m^?2 and a tensile strength of 31·3 MPa.     

Search for simulants of sulfur mustard through sorption studies in elastomers

With an aim to probe some of the safe and commercially available nonsulfur chemicals as simulants of sulfur mustard for testing of protective materials, the sorption of bis(2‐chloroethyl) ether (2‐CEE), 1,6‐dichlorohexane, bis(4‐chlorobutyl) ether, n‐octane (OCT), dimethyl methylphosphonate, and ethylene glycol through butyl rubber (IIR) and polyisoprene (PI) rubber was studied at 30 ± 2°C using gravimetric method. Among these compounds, sorption of OCT was maximum while bis(4‐chlorobutyl) ether was sorbed least. The sorption of dimethyl methylphosphonate was intermediate between 2‐CEE and 1,6‐dichlorohexane. With the exception of OCT/IIR, OCT/PI, and 2‐CEE/PI, all other simulant/elastomer systems showed non‐Fickian behavior, implying the potential of OCT as a model compound. The diffusivity of OCT was investigated in IIR and PI; the diffusion coefficient values for OCT/IIR and OCT/PI systems differed by one order of magnitude, being 6.95 × 10^?15 m²/s and 3.74 × 10^?14 m²/s, respectively, indicating the relative impermeability of IIR. The magnitude and dynamics of sorption in OCT/IIR as a function of its concentration and the amount of filler were further studied using the automated gravimetric analyzer. Incorporation of carbon black in IIR further reduced the extent of sorption, thereby implying an improvement in barrier performance. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1801–1806, 2007     

丁基橡胶/有机黏土纳米复合材料的结构和性能

采用溶液插层法制备了丁基橡胶／有机黏土纳米复合材料,并用透射电子显微镜和X射线衍射仪研究了该纳米复合材料的形态结构。结果表明,丁基橡胶／有机黏土纳米复合材料是插层型的纳米复合材料。与丁基橡胶相比,该纳米复合材料具有优异的力学性能和气体阻隔性能,并且这2种性能均随有机黏土用量的增加而增强。填料的形状会对该纳米复合材料的气体阻隔性能产生影响。     

OMMT/IIR纳米复合材料结构与性能的研究

采用熔体插层法制备有机蒙脱土(OMMT)／IIR纳米复合材料。试验结果表明，OMMT／IIR纳米复合材料是插层型纳米复合材料；与无机粘土／IIR微米复合材料及IIR相比，OMMT／HR纳米复合材料具有良好的物理性能，且其物理性能均随OMMT用量的增大而明显提高；与IIR相比，OMMT／HR纳米复合材料具有优异的气密性。     

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。     

不同金属盐破乳对丁基橡胶硫化行为的影响

为考察金属盐凝固剂对丁基橡胶(isobutylene isoprene rubber,IIR)硫化行为的影响,采用流变仪研究了搅拌破乳及11种金属盐破乳后IIR的硫化历程,并分析了其硫化动力学。研究发现金属盐的阳离子及阴离子种类对硫化过程均有显著影响。与传统Ca²⁺凝固剂相比,过渡金属离子Cu²⁺、Zn²⁺破乳会延长焦烧期及正硫化时间,降低硫化表观活化能,硫化膜储能模量较高。与搅拌破乳相比,主族金属离子Ca²、Mg²⁺、Al³⁺破乳对硫化过程影响较小。阴离子Cl^-及NO₃^-有显著的硫化抑制作用,降低硫化表观速率常数,延长正硫化时间;阴离子SO₄^2-和OAc^-对IIR的硫化历程影响较小,相应的IIR硫化胶具有更高的模量。