1,2-丁二烯在连续聚合SSBR中的抑凝机理及应用

中国石油大学以正丁基锂为引发剂,环己烷/己烷为溶剂,采用间歇聚合工艺模拟溶聚丁苯橡胶(SSBR)聚合过程的凝胶生成实验,考察了1,2-丁二烯的抑凝机理。结果表明,1,2-丁二烯具有明显抑凝作用,加入质量分数为(1～5)×10-5时,产品的凝胶质量分数在0.010%以内;加入质量分数高于5×10-5时,产品的凝胶质量分数低于0.001%;加入质量分数超过1×10-4时,对聚合反应速率和单体转化率有影响。1,2-丁二烯作为     

结构改性钼系1,2-聚丁二烯橡胶的研究

钼系催化丁二烯1,2聚合,催化体系中n(Mo)/n(Bd)=2.0×10-4,n(Al)n(Mo)=30,结构改性剂用量为单体质量的1%～5%(质量分数),聚合温度为60℃,反应时间为4 h时,转化率超过85%,聚合物的1,2结构含量超过85%(质量分数),数均分子量在2×105～3×105,分子量分布在3～4之间.通过结构改性剂的加入,聚合物存在支化结构,聚合胶液粘度明显降低,与镍系顺丁橡胶的胶液粘度相近,可以进行工业化生产.     

白炭黑补强不同结构溶聚丁苯橡胶的性能研究

研究白炭黑补强不同结构溶聚丁苯橡胶(SSBR)的性能。结果表明:1,2-丁二烯质量分数越大,相对分子质量分布越窄,胶料的加工性能越差;顺式1,4-丁二烯质量分数越大,胶料的交联密度越大,硫化速度越快;SSBR2466的1,2-丁二烯质量分数最大,胶料抗湿滑性能最好;SSBR5260H的苯乙烯和1,2-丁二烯质量分数较大,改性基团使其与白炭黑的相互作用强,胶料物理性能和抗湿滑性能好,滚动阻力低。     

SBS生产工艺控制及质量影响因素分析

对苯乙烯-丁二烯-苯乙烯嵌段聚合物(SBS)生产过程中,聚合原材料杂质含量、聚合活性剂、引发剂、偶联剂用量等工艺条件进行了总结,通过产品相关理化数据分析及产品凝胶色谱图(GPC)的对比,探讨和分析了产品内在质量差异及影响因素,提出了稳定控制和提高产品质量所应采取的工艺措施:聚合反应引发温度控制在42℃左右,聚合最高温度为105℃左右;控制系统中四氢呋喃(THF)的质量分数为5×10~(-5)～1×10~(-4);控制溶剂中水的质量分数不大于1×10~(-5);在转产或停工检修后开车时,根据产品GPC的变化分析,及时调整引发剂、偶联剂的工艺条件,实现了SBS产品的工业化平稳生产。     

磷酸三丁酯对钼催化体系聚合丁二烯的影响

以磷酸三丁酯(TBP)改性MOCl5(简称MoTBP)为主催化剂,Al(OPhCH3)(i-Bu)2(简称Al)为助催化剂催化聚合丁二烯(Bd),通过紫外可见光谱对MoTBP的催化行为进行了表征,探讨了TBP用量对Bd聚合反应的影响,研究了适宜的聚合条件,并与辛醇取代MoCl5,[MoCl3,(OC8H17)2]催化体系进行了比较.结果表明,经TBP改性MoCl5,催化活性明显提高,TBP与MoCl5最佳摩尔比为2.0;最佳聚合条件:AL/MoTBP(摩尔比)为20,MoTBP/Bd(摩尔比)为(1.0～3.0)×10-4,Bd质量浓度为0.14 g/mL,聚合温度为60℃,聚合时间为6 h;与MOCl3(OC8H17)2体系相比,MoTBP体系催化聚合所得1,2-聚丁二烯的相对分子质量减小,相对分子质量分布加宽,1,2-结构摩尔分数为85.7%左右,其中以全同立构体(摩尔分数为53.25%)为主,且含有质量分数小于0.32%的凝胶.     

1，4-双（2，3-环氧丙氧基）丁烷端基极性改性溶聚丁苯橡胶的制备及性能研究

以正丁基锂为引发剂、环己烷为溶剂,采用醚类结构调节剂,以阴离子聚合法制备溶聚丁苯橡胶（SSBR）,然后用1,4-双（2,3-环氧丙氧基）丁烷封端极性改性SSBR,考察SSBR的优化合成条件和优化改性条件。结果表明：当单体苯乙烯/丁二烯质量比为25/75、单体质量分数为9.3%、每千克溶剂中四氢呋喃用量为300 mg和醚类结构调节剂用量为135 mg、反应温度为60～65 ℃时,制得适用于轮胎胎面胶的分子中1,2-丁二烯结构质量分数为62%～67%的SSBR;1,4-双（2,3-环氧丙氧基）丁烷/正丁基锂物质的量比为0.5/1～0.7/1、改性温度为56.0～65.0 ℃时,SSBR的改性效果较好。1,4-双（2,3-环氧丙氧基）丁烷端基改性SSBR胶料各项性能达到国外同类SSBR胶料水平,与未改性SSBR胶料比,其抗湿滑性能提升,滚动阻力降低。     

耐低温溶聚丁苯橡胶的合成与性能

以2-（乙氧甲基）四氢呋喃为结构调节剂,采用负离子聚合法合成了耐低温溶聚丁苯橡胶（SSBR）,考察了2-（乙氧甲基）四氢呋喃用量和反应温度对SSBR微观结构的影响,研究了SSBR的物理机械性能和动态力学性能,并与市售SSBR产品进行了对比。结果表明,该调节剂具有温度不敏感性,当反应温度为60℃、2-（乙氧甲基）四氢呋喃质量分数为140×10^-6时,所制得SSBR的结合苯乙烯与1,2-结构质量分数分别为15%和50%,苯乙烯在分子链上的无规度达到100%,玻璃化转变温度为-47℃;与市售SSBR产品相比,所制得SSBR的回弹性较好,永久变形小,耐磨性能良好,耐老化性能略优,滚动阻力较低。     

用混合偶联剂合成三峰分布高乙烯基溶聚丁苯橡胶

以环己烷/己烷为溶剂、正丁基锂为引发剂、乙基四氢糠基醚(ETE)为结构调节剂、二甲基二氯硅烷与四氯化硅为混合偶联剂,采用间歇聚合工艺合成了高乙烯基溶聚丁苯橡胶(SSBR),对ETE调节体系、混合偶联体系以及聚合工艺条件等进行了探讨,并与国外同类产品进行了性能比较。结果表明,在聚合引发温度为35℃、单体质量分数为13%、丁二烯与苯乙烯质量比为74/26、ETE质量分数为(200~250)×10-6及四氯化硅与二甲基二氯硅烷的摩尔比为0.34~0.36的条件下,可以合成具有三峰分布的高乙烯基SSBR。模试和中试结果均表明所合成产物的性能已达到国外同类产品的水平。白炭黑更适合作为开发该牌号硅改性产品的填料。     

乙二醇二乙氨基乙基丁基醚存在下的丁二烯负离子聚合

研究了以乙二醇二乙氨基乙基丁基醚(GABE)为调节剂,正丁基锂为引发剂的丁二烯负离子聚合的聚合动力学及聚合物的微观结构。结果表明,随着GABE用量的增加,丁二烯的聚合速率增加,聚丁二烯中1,2-结构质量分数增加,聚合温度升高,聚合速率增加,但聚丁二烯中1,2-结构质量分数有所降低。     

钼系催化体系制备高乙烯基含量丁苯共聚物的研究

以磷酸三丁酯(TBP)为配体改性的五氯化钼(MoCl5)为主催化剂、二丁基镁[Mg(Bu)2]为助催化剂组成二元催化体系,在丁二烯(Bd)物质的量浓度为2.6×103 mol·L-1和Bd/苯乙烯(St)质量比为3的条件下进行丁苯共聚物的配位聚合,研究催化体系和聚合条件对聚合反应的影响,并采用凝胶渗透色谱、傅里叶变换红外光谱、核磁共振氢谱、差示扫描量热法等对共聚物的微观结构进行分析。试验得出的最佳反应条件为:TBP/MoCl5物质的量比2,MoCl5/单体物质的量比1×10-3,Mg(Bu)2/MoCl5物质的量比3,聚合温度70℃,聚合时间12 h。在该条件下,Bd和St聚合活性较高,共聚物的数均相对分子质量为1.24×105,相对分子质量分布较宽,Bd单元中1,2-结构物质的量分数大于0.85,聚合产物为高乙烯基含量无规丁苯共聚物。     

溶聚丁苯橡胶2557A与5025-2结构和性能的对比研究

采用傅里叶变换红外光谱分析仪、凝胶渗透色谱-激光光散射-自动黏度在线检测仪、动态力学性能分析等手段,对国产溶聚丁苯橡胶(SSBR 2557A)的微观结构及基本性能进行了分析与表征,并与国外丁苯橡胶(SSBR 5025-2)产品作了对比,同时对其在轿车子午线轮胎中的应用性能进行了分析。结果表明,SSBR 2557A顺式含量和反式1,4结构含量几乎相同,而SSBR 5025-2的顺式1,4含量明显大于反式1,4结构含量,两种胶都为高乙烯基含量结构。与SSBR 5025-2相比,SSBR 2557A支化度较低。SSBR 2557A在0℃时的tanδ高达0.779,表明其降低滚动阻力的同时,显著提高了轮胎的抗湿滑性。     

无规溶聚丁苯橡胶生产技术探讨

对生产无规溶聚丁苯橡胶的引发体系，１，２－结构含量，聚合反应，锡偶联前补加丁二烯封端等技术进行了探讨，并对国外生产无规ＳＳＢＲＳ工艺和国内新建ＳＳＢＲ装置的建议流程作了简介。     

Polymerization of conjugated dienes initiated by soluble organosodium compounds in hydrocarbon solvents

Polymerization of butadiene and isoprene in hydrocarbon solvents initiated by unsolvated organosodium compounds was studied. It was found that the polymer molecular weight and the MWD are determined mainly by chain transfer to solvent and polymer, and no chain transfer to monomer was observed even in the case of isoprene. The overall polymerization rate is proportional to the concentrations of the monomer and the initiator. Apparent chain propagation rate constants were found to be 0.11 litre mol^?1 s^?1 for butadiene and 0.065 litre mol^?1 s^?1 for isoprene polymerization in heptane at 30°C. It is suggested that associated (dimeric) forms of polydienylsodium active centres play an important role in chain propagation, being responsible for a stronger chain transfer and a greater 1,2-butadiene, or 3,4-isoprene, unit content than in polymerization with other alkali metals.     

CPP裂解气脱氧净化工业实验

50万t/a催化热裂解(CPP)制乙烯装置产生的裂解气中氧气含量较大,其会形成氧自由基并会引起重二烯烃的聚合反应而堵塞设备,同时裂解气中的氧气含量较高会影响聚合级乙烯和丙烯的产品质量。另外,氧加氢后生成水,水对后续的深冷工序有很大影响。某公司提供的脱氧脱氮催化剂,实际运行中结焦严重,再生频繁,最终被切除。后对裂解气除杂工艺进行更换,并与大连凯特利催化工程技术有限公司开展脱氧催化剂实验研究。目前氧含量由5×10-6降至1×10-6以下,达到预想除氧效果,具备实际工业应用条件。     

α-二亚胺镍溴化物/凹凸棒黏土负载催化剂催化乙烯聚合研究

A nickel-diimine catalyst [N, N'-bis(2,6-diisopropylphenyl)-1,4-diaza-2,3-dimethyl-1, 3-butadiene nickel dibromide, DMN] was supported on palygorskite clay for ethylene slurry polymerization. The effect of supporting methods on the catalyst impregnation was studied and compared. Pretreatment of the support with methylalumi-noxane (MAO) followed by DMN impregnation gave higher catalyst loading and catalytic activity than the direct impregnation of DMN. Catalyst activity as high as 5.42×105g PE·molNi-1·h-1 was achieved at ethylene pressure of 6.87×105 Pa and polymerization temperature of 20℃. In particular, the morphological change of the support during MAO treatment was characterized and analyzed. It was found that nano-fiber clusters formed during the support pretreatment, which increased the surface area of the support and favored the impregnation of the catalyst. The investigation of polymerization behavior of supported catalyst revealed that the polymerization rate could be kept at a relatively h     

Structural reorganization of the PPy/DBS films caused by the reduction branch of potentiodynamic polymerization

Polypyrrole/dodecylbenzenesulfonate (PPy/DBS) films were synthesized in aqueous solution by cyclic voltammetry. The polymerization carried out at slow scan rates produces two cathodic peaks on the reduction branch. A single reduction peak was obtained at scan rates higher than 50 mV s⁻¹. Two different polymeric structures have been proposed to explain the observed cathodic splitting. Structure I was associated with the organization reached by slow rate electropolymerization processes. Structure II was obtained when I was permanently modified by electrochemical reduction. Under electrogeneration by potential cycling a constant amount of I is generated on every cycle, providing a constant reduction peak A charge. However, the charge involved in peak B, where structure II is reduced, increases with the cycling. Structure I has a lower energetic content than structure II: it is reduced at lesser cathodic potentials than II. Voltammetric and EDX measurements indicated that a main cationic transport occurred during the redox process of the PPy/DBS. However, a certain amount of Na⁺ cations was not interchanged, since they were stabilized inside the polymer, forming ion pairs with an extra quantity of DBS⁻ anions trapped in the polymer matrix during the polymerization process.     

Living polymerization of 1,3-butadiene by a Ziegler-Natta type catalyst composed of iron(III) 2-ethylhexanoate, triisobutylaluminum and diethyl phosphite

Living characteristics of facilely prepared Ziegler-Natta type catalyst system consisting of iron(III) 2-ethylhexanoate, triisobutylaluminum and diethyl phosphite have been found in the polymerization of 1,3-butadiene in hexane at 40 °C. The characteristics have been well demonstrated by: a first-order kinetics with respect to monomer conversion, a narrow molecular weight distribution (M_w/M_n = 1.48-1.52) of polybutadiene in the entire range of polymerization conversion and a good linearity between M_n and the yield of polymer. Feasible post-polymerization of 1,3-butadiene and block co-polymerization of 1,3-butadiene and isoprene further support the living natures of the catalyst bestowed with. The current catalyst system is highly active (yield > 80%, 35 min), providing polybutadiene with 1,2, cis-1,4 and trans-1,4 units about 44.0%, 51.0% and 5.0%, respectively.     

星形苯乙烯-异戊二烯-丁二烯嵌段共聚物结构与性能的关系

以环己烷为溶剂,苯乙烯(St)、丁二烯(Bd)、异戊二烯(Ip)为单体,正丁基锂为引发剂,采用负离子聚合法合成了集成橡胶———星形苯乙烯-异戊二烯-丁二烯嵌段共聚物(SIBR),考察了星形SIBR的相对分子质量、侧基含量、嵌段比(即Ip的均聚物链段与St-Bd的无规共聚物链段的质量比)与其性能的关系。结果表明,在考察范围内,星形SIBR的拉伸强度和撕裂强度随着其相对分子质量的增加而增大。随着1,2-和3,4-结构含量之和的增加,0℃和60℃时的损耗因子均有所增大。固定St/Bd(质量比)为1/3,随着嵌段比的逐渐降低,所得星形SIBR的门尼黏度逐渐增大;嵌段比为20/80时所得星形SIBR具有较好的力学性能与动态力学性能,且与溶聚丁苯橡胶2300、2305以及天然橡胶相比,具有更好的抗湿滑性和滚动阻力的平衡。     

一种新型聚丁二烯

MoCI_4OR与适当烷基铝组成的催化体系,对丁二烯聚合有很高的催化活性.在聚合温度为70℃、催化剂用量Mo/Bd比为5×10~(-5)时,转化率可达80%以上.聚合温度为30—70℃范围内所得聚合物分子量分布宽度指数为1.5—2.0.烯丙基卤等极性添加剂可以调节聚合物分子量和链结构,以烯丙基碘效果最好;随着烯丙基碘用量的增加,聚合物分子量降低,1,2-链节增多,链结构规整性增加.聚合物基本性能是:1,2-链节含量,88-97%;特性粘数,1.8—6.2(dl/g)玻璃化温度,-10—-27℃;屈服强度,6.5—8.5(kg/cm~2);断裂强度,12—25(kg/cm~2)断裂伸长,1700—2900%.     

20世纪SSBR合成技术进展：Ⅱ.聚合工艺及工程设备的开发

评述了溶聚丁苯橡胶连续聚合工艺中如何防止大分子凝胶的形成以及各种聚合设备体系的特点,并对开发我国溶聚丁苯橡胶的生产技术提出了建议。