共轭二烯烃对催化裂化汽油安定性的影响

通过对茂名石化公司炼油厂 3套装置的催化裂化汽油组成及其诱导期、实际胶质的研究 ,发现共轭二烯烃对催化裂化汽油安定性产生重大影响。共轭二烯烃含量的多少可以用二烯值来表示。结果表明 ,催化裂化汽油的诱导期随二烯值的增大而减少 ,实际胶质随二烯值的增大而增加。烯烃含量大小与催化裂化汽油诱导期长短没有明显的对应关系。共轭二烯烃是影响催化裂化汽油诱导期和抗氧防胶性能的主要原因     

盾构隧道密封垫长期防水性能预测的试验研究

为了建立盾构隧道弹性密封垫橡胶的老化系数模型,开展热氧加速老化试验. 该模型采用伸长率与应力的比值作为性能劣化指标,可以预测橡胶在不同温度和时间状态下的性能,对密封垫的长期服役状态进行预测. 通过一系列水密性试验,研究密封垫防水能力受服役时间和张开量的影响规律. 研究结果表明,橡胶的拉伸强度在老化前期受拉断伸长率变化的影响迅速下降,后期主导因素转变为拉伸模量;老化系数随着时间的增加而持续下降,但下降速度逐渐减小,最终服役百年后的老化系数为0.364;密封垫耐水压折减系数随着张开量的减小而降低,总体上小于老化系数. 基于试验结果,建立以服役时间和张开量为自变量的耐水压折减系数的预测公式.     

New polymerization of dienes and related monomers catalyzed by late transition metal complexes

This article reviews recent studies on the polymerization of 1,6-heptadienes and 2-aryl- and 2-alkoxy-1-methylenecyclopropanes catalyzed by Co, Fe, and Pd complexes. Co and Fe complexes with bis(imino)pyridine ligands catalyze the cyclopolymerization of 1,6-heptadiene in the presence of MMAO to produce the polymer, which contains five-membered rings in the monomer units. The polymers with cis- or trans-five-membered rings are obtained selectively, depending on the complex used in the polymerization. The catalyst, prepared from the Co complex having a bis(imino)pyridine ligand and MMAO, promotes the polymerization of 2-aryl-1-methylenecyclopropanes without ring-opening. The reaction under ethylene atmosphere produces alternating copolymer of the two monomers to yield the polymers composed of the C4 repeating unit with a 1,1-cyclopropanediyl group. The alternating copolymer of ethylene and 7-methylenebicyclo[4.1.0]heptane undergoes thermal rearrangement to afford the polymer with CC double bond in main chain. A radical pathway is proposed. Dinuclear π-allylpalladium complexes with bridging Cl ligands initiate living polymerization of 2-alkoxy-1-methylenecyclopropanes, which accompanies ring-opening of the monomer, to afford the polymers composed of the C₃ repeating units having alkoxy and vinylidene groups. A cyclic dinuclear π-allylpalladium complex reacts with 2-alkoxy-1-methylenecyclopropane in the presence of pyridine to produce the living polymer with macrocyclic structures. Block copolymerization of the two monomers that contain OR or O(CH₂CH₂O)R as the substituents on the three-membered ring, results in the polymers with hydrophobic and hydrophilic segments.     

共轭二烯烃溶液聚合连续搅拌塔式反应器的研究—流动模型

针对可用于共轭二烯烃溶液聚合的连续搅拌塔式反应器的宏观流动过程进行了研究，提出了“多级、级际有限混和、伴有死区和级际旁路”的流动模型，证明并得到了模型参数与停留时间分布的矩之间的函数关系，给出了确定模型参数的过程和实例。研究结果表明，提出的多参数流动模型和模型参数的确定方法对研究连续搅拌塔式反应器的流动模式具有指导意义。     

催化裂化轻汽油选择性加氢除二烯烃工艺研究

主要进行了催化裂化轻汽油选择性加氢除二烯烃工艺条件优化研究,从反应温度、氢/油体积比和反应压力等3个方面考察了其对选择性加氢和3-甲基-1-丁烯异构为2-甲基-1-丁烯的异构化率的影响,确定选择性加氢的较优工艺条件为反应温度60℃、氢/油体积比30、反应压力1.5 MPa。在此基础上进行了选择性加氢催化剂1500 h寿命试验。试验数据表明,在1500 h的考察期内,催化剂表现出良好的活性稳定性。     

Ni-La／Al2O3催化剂上催化裂化轻汽油的选择性加氢

以γ-Al_2O_3为载体,制备了Ni-La/Al_2O_3双金属选择性加氢催化剂,并用于催化裂化轻汽油的选择性加氢反应。考察了工艺条件对选择性加氢反应的影响。结果表明,二烯烃转化率和单烯选择性随着反应温度的升高而增加,但超过75℃二烯烃转化率已无明显增加,且单烯选择性下降;随着反应压力的升高,二烯转化率提高,但单烯损失较大;二烯烃转化率和单烯选择性随着空速的提高分别呈现下降和上升的趋势;氢气量应该严格控制,否则不仅造成浪费,还会使单烯损失增大。最佳的反应条件:温度75℃、压力1.0MPa、空速10h~(-1)、氢油比为8。在该条件下,催化裂化轻汽油中二烯烃转化率可达到97.8％,单烯烃损失小于2％。表明该催化剂具有良好的加氢活性和选择性,有很好的研究开发前景。     

Regioselective Arylboration of 1,3-Butadiene

A method for the regioselective 1,2-arylboration of 1,3-butadiene, a feedstock chemical, is reported. The reactions result in the formation of products that can be easily elaborated to other structures. The mechanistic details of this process are also discussed.     

三元乙丙橡胶硫化胶粉改性聚丙烯的研究

采用三元乙丙橡胶（EPDM）与EPDM硫化胶粉复合作为聚丙烯（PP）抗冲改性剂,研究了EPDM硫化胶粉和交联剂DCP用量对PP复合材料性能的影响。结果表明,PP复合材料的拉伸强度和弯曲强度随着硫化胶粉含量的增加而提高,冲击强度明显改善;而DCP用量增加对PP复合材料的拉伸强度和弯曲强度产生不利影响,少量DCP有助于提高PP复合材料的冲击强度;由DSC分析可知,硫化胶粉使PP熔体的结晶温度明显提高。     

Effects of virgin Ethylene–Propylene–Diene–Monomer and its preheating time on the properties of natural rubber/recycled Ethylene–Propylene–Diene–Monomer blends

Blending of natural rubber/recycled Ethylene–Propylene–Diene–Monomer (NR/R-EPDM) blends was carried out. A fixed amount of carbon black and virgin Ethylene–Propylene–Diene–Monomer (EPDM) were also introduced into the blends. Applications of two different processing methods were carried out to improve the cure compatibility, crosslink distribution, and hence mechanical properties of the blends. Simple processing method was done by mixing the entire additives and rubbers on a laboratory-sized two-roll-mill at ambient temperature. Whereas, reactive processing method was conducted by mixing virgin EPDM, recycled EPDM and other compounding ingredients using an internal mixer, the compound was later preheated according to designated time before blending with natural rubber and carbon black. Results revealed that the enhancement of the physical and mechanical properties was significantly achieved towards preheating time of EPDM/R-EPDM blends. The improved properties in the blends suggested that the reactive processing method had led to more homogeneous blends due to a better crosslink distribution and more homogeneous carbon black distribution.     

二烯烃对轻汽油醚化过程的影响

研究了催化裂化轻汽油中共轭二烯烃在醚化条件下的反应。随着反应温度的提高 ,二烯烃聚合反应转化率增大。随着醇烯摩尔比和空速的增大 ,二烯烃聚合转化率下降 ,说明适当提高空速和醇烯比有利于抑制二烯烃的聚合。在反应物料中加入阻聚剂对二烯烃聚合反应影响不大 ,证明二烯烃的聚合不是按照自由基机理进行 ,而是在酸催化剂作用下进行的。二烯烃聚合产物影响催化剂的活性 ,原料中二烯烃含量越高 ,催化剂活性下降速率越大。醚化反应过程中二烯烃的聚合产品还对醚化产品的颜色和实际胶质有较大影响。