丁腈橡胶的催化加氢反应

以三(三苯基磷)氯化铑(简称Rh)为催化剂、氯苯为溶剂,在高压釜中对丁腈橡胶(NBR)进行加氢反应,制得了氢化丁腈橡胶(HNBR),考察了Rh/NBR(质量比)、胶液质量分数、氢气压力、反应温度和反应时间对加氢度的影响.结果表明,在Rh/NBR为150×10-6～200×10-6、胶液质量分数为4％ ～6％、氢气压力为...     

丁腈橡胶非均相催化加氢研究进展

丁腈橡胶（NBR）选择性催化加氢是制备高附加值、高性能氢化丁腈橡胶（HNBR）的一个重要过程。将链段中C==C双键加氢饱和而保留氰基基团,不仅可保持其原有的耐油性和耐磨性,而且可极大地改善其耐侯性、耐臭氧性等。本文介绍了NBR加氢的几种工艺,着重综述了NBR非均相催化加氢的研究进展及发展方向,探讨了负载型催化剂的载体孔道结构和表面性质及活性组分组成对NBR加氢性能的影响。本文还对非均相催化加氢过程中的溶剂效应、催化剂的回收和循环再生进行了阐述,提出溶剂对催化加氢速率和加氢度都有重要影响,溶剂的受氢能力（β值）是影响加氢过程的关键参数。催化剂失活的主要原因是表面活性位点被聚合物覆盖,而利用有效的溶剂洗涤或者采用催化剂表面功能化的方式,可促使活性位再次暴露,恢复其加氢活性。最后,对非均相加氢制备高附加值HNBR体系中的催化剂设计、溶剂效应和催化剂再生等发展方向进行了展望。     

丁腈橡胶的烯烃复分解及其产物的非均相加氢

采用烯烃复分解方式制备低相对分子质量的丁腈橡胶并对其进行非均相加氢,考察了烯烃复分解催化剂加入量、反应温度及反应时间对丁腈橡胶相对分子质量及其分布的影响。结果表明,在10 m L三氯甲烷中溶解1 g丁腈橡胶、催化剂用量0.001 g、反应温度30℃及反应时间3 h的条件下,所制备丁腈橡胶的数均分子量为(1.5~5.5)×104,重均分子量为(3.0~12.0)×104。采用非均相催化剂对低相对分子质量丁腈橡胶进行加氢的氢化度可达99%以上。     

氢化丁腈橡胶的制备

对国内外丁腈橡胶加氢方法作了较为详尽的评述,指出了各方法的优点,并对制备氢化丁腈橡胶的研究方向作了展望。     

Homogeneous catalytic hydrogenation of hydroxyl‐terminated liquid nitrile rubber

It was difficult to obtain high degree of hydrogenation of hydroxyl‐terminated liquid nitrile rubber (HTBN) by using homogeneous noble metal catalyst because the hydroxyl (? OH) in HTBN was likely to cause catalyst poisoning. In this study, with hexamethyl disilylamine protecting ? OH, a good yields of hydrogenated HTBN was synthesized through the use of homogeneous metal catalyst. The effects of catalyst concentration, reaction time, hydrogen pressure, and temperature on the hydrogenation of HTBN were investigated and obtained the following optimum process parameter values: catalyst mass fraction of 0.8%, reaction time of 8 h, pressure of 1.6 MPa, and temperature of 100°C. Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy were used to characterize the hydrogenation product of the protected HTBN, indicating that under certain conditions a high degree of hydrogenation of HTBN can be achieved. Only the carbon–carbon double bonds (C?C), not the ? CN bonds, are subject to hydrogenation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

铑-钌双金属配位催化剂氢化丁腈橡胶的流变性能

研究了铑-钌双金属配位催化剂体系制备的氢化丁腈橡胶(HNBR)的相对分子质量及其分布、剪切应力与剪切速率的关系、表观黏度与剪切速率的关系、表观黏度与温度的关系以及口型膨胀情况。结果表明,制备的HNBR的加工流变行为具有较高的剪切速率敏感性和很低的加工温度敏感性,且其加工流变行为与已工业化生产的国外同类产品相当。     

Hydrogenation of epoxidized natural rubber in the presence of palladium acetate catalyst

Expoxidized natural rubber has been selectively hydrogenated in the presence of a homogeneous palladium acetate catalyst. The hydrogenated product has been characterized by infra-red and nuclear magnetic resonance spectroscopies. No change is noted in the epoxy content of the polymer after the reaction. The catalyst is highly selective in reducing carbon-carbon double bonds in the presence of epoxy groups. Natural rubber has also been hydrogenated for a comparative study. The rate constant of hydrogenation is decreased with increase in epoxy content of the polymer.     

Catalytic hydrogenation of nitrile–butadiene copolymer emulsion

Two processes have been developed for the selective hydrogenation of the CC bonds in nitrile–butadiene rubber emulsions (NBR emulsions) in the presence of a number of RuCl₂(PPh₃)₃ complex catalysts. One of the processes is carried out in a homogeneous system, in which an organic solvent, which can dissolve the NBR polymer and catalyst and which is compatible with the emulsion, is used. The other process is carried out in a heterogeneous system, in which an organic solvent which is capable of dissolving the catalyst and swelling the polymer particle but is not miscible with the aqueous emulsion phase, is used. In both processes, quantitative hydrogenation of the CC bonds of the NBR emulsion is achieved in the presence of RuCl₂(PPh₃)₃. It is also found that the addition of certain types of additives can improve the activities of the Ru-based catalysts. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 667-675, 1997     

丁腈橡胶非均相加氢催化剂失活原因及再生性能研究

对丁腈橡胶非均相催化加氢制备高附加值氢化丁腈橡胶过程中催化剂失活的原因进行了探究,发现造成催化剂活性下降的原因并不是贵金属纳米颗粒的流失、团聚或中毒,而是催化剂表面的活性位被聚合物覆盖而无法与反应物接触,因此将覆盖在活性位上的聚合物进行脱除才是催化剂再生和重复利用的关键。根据相似相容原理选择单溶剂或者混合溶剂对反应后催化剂进行处理,结果表明经过乙酸乙酯、丁酮、N,N-二甲基甲酰胺以及N-甲基吡咯烷酮这四种有机溶剂处理后,其催化加氢活性可以恢复至新鲜催化剂活性的90%;当用混合溶剂处理后,其催化活性可以提高至新鲜催化剂活性的95%,且循环利用4次其催化活性仍能保持不变。     

大孔离子交换树脂吸附氢化丁腈橡胶胶液中的铑和钌

研究了大孔离子交换树脂对氢化丁腈橡胶(HNBR)氯苯胶液中铑和钌贵金属的吸附能力,考察了温度对树脂吸附率的影响,并采用焚烧法回收了树脂上的金属铑和钌。结果表明,R 02、A 40、R 01树脂对铑和钌具有很好的吸附能力;当吸附温度为90℃时,A 40树脂的饱和工作吸附量(以干树脂计)为铑7.86 mg/g和钌1.09 mg/g;升高温度有助于提高树脂对铑和钌的吸附率,而且对铑的吸附效果更明显;高温焚烧回收树脂上的铑和钌,回收率可超过98.0%。     

饱和丁腈橡胶的制备

综述了用共聚合法、乳液加氢法和溶液加氢法制备饱和丁腈橡胶的技术,介绍了工艺条件、加氢设备及残留催化剂铑的脱除。     

丁腈橡胶催化加氢反应研究

氢化丁腈橡胶具有良好的耐油性和耐氧性,广泛应用于汽车和石油行业,通过丁腈橡胶溶液均相催化加氢制得,采用铑类和钯类均相催化剂。考察不同溶剂、催化剂及m(Ru)∶m(丁腈橡胶)对丁腈橡胶加氢的影响。采用红外光谱法和核磁法对氢化丁腈橡胶的结构进行分析,筛选出价廉、活性高和选择性高的催化剂。结果表明,在丁腈橡胶加氢反应中,丁酮可作为溶剂,Ru(PPh3)3Cl2催化剂具有高活性和高选择性。在丁酮200 m L、丁腈橡胶5 g、Ru(PPh3)3Cl2催化剂、m(Ru)∶m(丁腈橡胶)=0.000 20∶1、反应温度140℃、氢压8.0 MPa和反应时间4 h条件下,加氢度和选择性均达到100%,具有与Rh(PPh3)3Cl相当的催化性能。     

HNBR补强填充体系的研究

研究了白炭黑及改性酚醛树脂（SP6701）对氢化丁腈橡胶（HNBR）补强效果的影响。结果表明,在N550用量不变的情况下,白炭黑的加入能显著提高HNBR硫化胶的定伸应力和硬度,改善HNBR的耐热空气老化性能;加入SP6701后,胶料的拉伸强度逐渐降低,拉断伸长率先降低后升高,硬度和定伸应力则显著增大,混炼胶的Payne效应则是随着SP6701含量的增加而增强。综合而言,SP6701能够明显提高硫化胶的硬度和定伸应力,但对于其它性能的影响很微弱,甚至会产生相反的影响。     

钌催化剂上苯加氢制环己烯的影响因素

综述了钌催化剂上苯选择性加氢的反应机理、催化剂制备过程中前躯体、制备方法、载体、添加剂(水,有机添加剂,无机添加剂)对催化剂催化性能的影响和反应过程中温度、压力、搅拌速率、催化剂用量及反应时间等对苯转化率、环己烯选择性和环己烯收率的影响。     

丁腈橡胶生产及市场分析

丁腈橡胶(NBR)具有优异的耐油性、卓越的耐磨性、耐溶剂性和耐热性,已被广泛用于汽车、石油开采与炼制、航空、纺织、印刷等领域.本文综述了近年来国内外NBR的生产及市场情况,对国内NBR的市场发展趋势进行了分析及预测.此外,本文还对国内NBR行业的发展提出了几点建议.     

Investigation on the mechanical properties and oil resistance of sulfur cured nitrile rubber/hydrogenated nitrile butadiene rubber blends

Nitrile rubber (NBR)/hydrogenated nitrile butadiene rubber (HNBR) blends with various ratios were compounded with internal mixer and two-roll open mill. Mechanical properties and low-temperature performance (TR10) of the NBR/HNBR blends after aging under different conditions were investigated. Furthermore, equilibrium swelling test and moving die rheometer (MDR) test were used to systematically investigate the effects of HNBR dosage on the crosslink densities and curing behaviors. Vulcanization torque and crosslink densities decreased with an increase in HNBR content. The crosslink density of pure HNBR is higher than that of pure NBR, which is related to the macromolecular structures of the rubber. Compression sets of the NBR/HNBR vulcanizates were correlated with HNBR dosage indicating a linear relationship. Low-temperature performance of the NBR/HNBR blends was improved after being aged in the synthetic hydrocarbon hydraulic oils (SH-1 and SH-2). This work shows that the low-temperature performance and oil resistance could be better balanced by blending NBR with HNBR, while the mechanical properties maintain relatively high level.     

Catalytic hydrogenation of carbon monoxide to alkenes over partially degraded iron-cobalt complexes

Complex-derived iron–cobalt alloy catalysts have been studied under conditions similar to those normally prevailing in industry. Despite reports in the literature indicating unusual selectivities with iron–cobalt alloy catalysts under atmospheric pressure conditions, no deviations from normal selectivity behaviour have been observed when studied under steady-state conditions and pressures of 2.0 MPa. However, when promoted with manganous oxide or supported on silica-alumina, substantial deviations from Anderson-Schulz-Flory statistics occur during the first few days on stream. These deviations gradually disappear with increasing time on stream leading to normal selectivity behaviour. The unsupported catalysts displayed remarkably high activity and selectivity maintenance, in contrast to supported catalysts, which show substantial oscillations in the catalytic behaviour.     

丁腈橡胶在反应加工设备中的催化环氧化

以叔丁基过氧化氢(TBHP)为氧化剂,MoO3为催化剂,在Haake转矩流变仪中对丁腈橡胶(NBR)进行环氧化改性,并用全反射傅里叶变换红外光谱对产物进行了表征,研究了反应条件对产物环氧度的影响。结果表明,在Haake转矩流变仪中,TBHP/MoO3构成的催化环氧化体系能够对NBR进行环氧化改性,得到环氧化NBR产物。反应时间、反应温度和催化剂用量等反应条件都会在不同程度上影响最终产物的环氧度;适宜的反应温度为70℃,反应时间为30～40 min,MoO3摩尔分数为NBR的1.5%,在此条件下,环氧化NBR的环氧度可达到3.6%。NBR的环氧化过程可视为准一级反应,随反应时间的延长,环氧化过程大致上经历快慢2个阶段;环氧化反应的表观活化能为36 kJ/mol。     

氢化丁腈橡胶的烯烃复分解反应

研究了丁腈橡胶经选择性催化加氢后得到的氢化丁腈橡胶(HNBR)在钌基催化剂Zhan 1 B作用下以及有无外加低分子烯烃条件下的烯烃复分解反应,并用尺寸排阻色谱-多角度激光光散射-黏度检测联用仪对HNBR的2种烯烃复分解反应产物的结构进行了表征。结果表明,钌基催化剂Zhan 1 B可以有效地催化HNBR的烯烃复分解反应,降低其相对分子质量;HNBR的烯烃自复分解反应(无外加烯烃)比交叉复分解反应(有外加烯烃)的效率低;相对分子质量相同时,自复分解反应产物的均方旋转半径及特性黏数值均低于相应的交叉复分解反应产物,由此推断HNBR的烯烃自复分解反应产物主要为环状结构,而交叉复分解反应产物主要为线型结构。     

国内丁腈橡胶生产情况及市场分析

综述了国内外丁腈橡胶的生产及市场情况，对国内丁腈橡胶的市场发展趋势进行了分析和预测。并针对入世后国内丁腈橡胶行业存在的不足提出了几点建议。