Molecular Dynamic Simulation on the Absorbing Process of Isolating and Coating of α-olefin Drag Reducing Polymer

The absorbing process in isolating and coating process of α-olefin drag reducing polymer was studied by molecular dynamic simulation method, on basis of coating theory of α-olefin drag reducing polymer particles with polyurethane as coating material. The distributions of sodium laurate, sodium dodecyl sulfate, and sodium dodecyl benzene sulfonate on the surface of α-olefin drag reducing polymer particles were almost the same, but the bending degrees of them were obviously different. The bending degree of SLA molecules was greater than those of the other two surfactant molecules. Simulation results of absorbing and accu-mulating structure showed that, though hydrophobic properties of surfactant molecules were almost the same, water density around long chain sulfonate sodium was bigger than that around alkyl sulfate sodium. This property goes against useful absorbing and accumulating on the surface of α-olefin drag reducing polymer particles; simulation results of interactions of different surfactant and multiple hydroxyl compounds on surface of particles showed that, interactions of different surfactant and one kind of multiple hydroxyl compound were similar to those of one kind of surfactant and different multiple hydroxyl compounds. These two contrast types of interactions also exhibited the differences of absorbing distribution and closing degrees to surface of particles. The sequence of closing degrees was derived from sim-ulation; control step of addition polymerization interaction in coating process was absorbing mass transfer process, so the more closed to surface of particle the multiple hydroxyl com-pounds were, the easier interactions with isocyanate were. Simulation results represented the compatibility relationship between surfactant and multiple hydroxyl compounds. The isolating and coating processes of α-olefin drag reducing polymer were further understood on molecule and atom level through above simulation research, and based on the simulation, a referenced theoretical basis was provided for practical optimal selection and experimental preparation of α-olefin drag reducing polymer particles suspension isolation agent.     

6-O-磺丁基-β-环糊精的合成及在非水毛细管电泳拆分碱性手性药物中的应用

合成了新型环糊精衍生物6-O-磺丁基-β-环糊精(SB-β-CD),并以其作为手性选择剂,对扑尔敏、多西拉敏、美克洛嗪和米安舍林4种碱性手性药物进行非水毛细管电泳拆分。考察了有机溶剂、电解质、手性选择剂浓度以及pH对分离度的影响。研究结果表明:扑尔敏、多西拉敏、美克洛嗪和米安舍林4种碱性手性药物全部达到基线分离。可见SB-β-CD在碱性药物拆分方面具有特殊能力,为碱性手性药物的拆分提供了一种准确、简便的分析方法。     

Polymerization Mechanism of α-Linear Olefin

利用密度泛函理论在B3LYP方法6-31G水平上对α-直链烯烃在TiCl₃/AlEt₂Cl催化体系的链增长规律进行了相应的计算．对反应物、产物以及各种可能的中间体和过渡态进行了全参数优化,在同一理论水平上对势能面上的全部驻点进行了振动频率分析,并从过渡态分别向反应物和产物方向进行了内禀反应坐标计算．计算结果表明,在TiCl₃/AlEt₂Cl催化剂优化的构型上首先形成配位化合物,进而形成过渡态,过渡态与配位化合物的能量差为40.687 kJ/mol,最后是双键打开和Ti-C(4)断裂,从而完成整个聚合反应历程．计算结果也初步表明随着α-直链烯烃碳原子数的增加,链增长机理未发生本质变化．由聚合反应活化能与α-直链烯烃碳原子数的关系可以看出,碳原子数为6～10时反应活化能较低,是聚合反应合成减阻剂的最佳选择．