End-capped polystyrene with 8-hydroxyquinoline group by ATRP method

8-Hydroxyqunioline end-capped polystyrene was prepared through atom transfer free radical polymerization (ATRP) with 8-(5-chloromethyl) quinolyl acetate as initiator. The results indicated that this polymerization is a first order reaction with respect to monomer conversion. The molecular weight increased linearly with monomer consumption and very narrow distribution of molecular weight was obtained (polydispersity index less than 1.2). The FT-IR and NMR results show that the 8-hydroxyquinloine group was chemically bonded to the polymer end and there is nearly one 8-hydroxyquinoline group in per polymer chain. All those data show that polymerization of styrene at such conditions displayed living characters. The polymer with 8-hydroxyqquinoline end group reacted with triethylaluminum to form polymeric light-emitting complex and single layer LED was prepared by common spin-coating method. The peak wavelength of LED based on synthesized polymeric complex was around 570 nm.     

Studies on the semirigid chain polyamide—poly(1,4-phenyleneterephthalamide)

In this article, the polycondensation of terephthaloyl chloride and p-phenylenediamine was systematically studied, including the liquid–crystalline state of the solution and the spinning of poly(1,4-phenyleneterephthalamide) (PPTA). High-molecular-weight PPTA with ε_inh = 5–7 was prepared and the main factors influencing the solution polycondensation of 1,4-phenylenediamine with terephthaloyl chloride were studied in detail. Experimental results showed that the water content of the reaction system, reactant concentration, and volume ratio of mix solvents have a great influence on the inherent viscosity of the poly(1,4-phenyleneterephthalamide) obtained. The highest ε_inh was obtained at 0.3M/liter reactant concentration in a mixed solvent ratio HMPA/DMAC of 4/1 (by volume), at 0.35M/liter reactant concentration in a mixed solvent of HMPA/NMP = 7/3, and at 0.5M/liter of reactant concentration in a mixed solvent of HMPA/THF = 9/1. The water content must be controlled to less than 100 ppm in the polymerization system. In the early stage of the polycondensation process, the ε_inh of the polymer obtained increased rapidly with time. The system gelled within 2 or 3 min, while the monomer conversion reached about 100%. However, the reaction of polycondensation continued after gelation and the ε_inh of the polymer increased appreciably. We have studied the viscosity behavior at 20–155°C for the anisotropic solution of PPTA in 100% sulfuric acid (ε_inh of PPTA 2.5–4.9). Experimental results showed that, at low concentrations the viscosity of isotropic solution increases with the increase of polymer concentration to reach a maxium near the critical polymer concentration, beyond which the solution changes to an anisotropic liquid–crystalline solution. The appropriate spinning region was obtained as shown in the phase diagram determined by viscosity, degree of depolarization anisotropy, and region of thermal depolymerization. Fibers of PPTA with high modulus and high tenacity were obtained by dry-jet wet spinning. The fibers obtained have a tenacity of ～22 g/denier, a modulus of ～600 g/denier, and elongation at break ～3.5%.     

甲苯稀释对AlCl3-EMIC型离子液体电镀铝工艺氢脆性的影响

采用甲苯作为AlCl3-EMIC(1-乙基-3-甲基咪唑)型离子液体的稀释剂,其中纯态离子液体由物质的量比为2∶1的无水AlCl3和EMIC组成。对比了纯态和按稀释剂与离子液体体积比为1∶1稀释后电镀铝的外观、微观形貌和氢脆性。结果表明,采用甲苯稀释离子液体虽然可以降低镀液的黏度,改善镀层外观和微观形貌,但对离子液体电镀铝工艺的氢脆性有负面影响。     

化学微交联聚氯乙烯的结构和性能

通过氯乙烯/邻苯二甲酸二烯丙酯(VC/DAP)悬浮共聚,合成了含部分凝胶结构的化学微交联PVC树脂,对微交联PVC的玻璃化转变行为、加工性能、消光性能、加热-形变行为和力学性能进行了研究。当DAP用量在0.25%mol以下时,PVC的玻璃化温度变动不大。凝胶含量的增加将导致交联PVC_d~T的光泽度下降,消光性能提高;塑化时间和加工扭矩均增加,加工性能急剧变差;加热变形值下降,最高使用温度提高。凝胶对PVC拉伸性能的影响较为复杂,但压缩永久变形则随凝胶含量的增加而下降,材料的弹性性能逐渐提高。     

提高等离子体裂解煤制乙炔收率的方案研究

将反应体系的温度升高到升华点以上 ,是提高等离子体裂解煤制乙炔收率的必由之路 .采用最小自由能方法研究了煤的 C- H- O热力学平衡体系 ,在此基础上提出了一种以煤层气甲烷为冷却剂的等离子体裂解煤制乙炔方案 ,初始反应体系的温度在 40 0 0 K以上 .理论的计算和分析结果表明 ,这种方案可获得较高的乙炔收率 ,而单位质量乙炔的比能耗很低 ,具有很好的经济效益和环境效益 .     

湿法腈纶生产的含腈废水处理实验研究

采用不同方法对湿法腈纶废水进行预处理，比较了它们的处理效果和特点。研究中使用的菌种预处理方法达到了理想的效果，废水中大分子有机污染物被迅速、高效地分解为挥发性脂肪酸和氨氮等，为后续的接触氧化以及反硝化创造了良好的条件，COD和TKN的总去除率分别为92％和85％，最终出水达到或优于行业二级排放标准。     

高聚合度聚氯乙烯的加工性能

本文对高聚合度聚氯乙烯(H-PVC)的发展及其优异的物理机械性能作了简要介绍;着重分析了H-PVC的加工性能和表征方法,并讨论了分子特性和颗料特性及加工组成、加工条件对加工性能的影响,提出了改进H-PVC加工性能的方法。     

不饱和酸结构对不饱和聚酯树脂固化行为的影响

通过IR分析了用顺酐和反酸与聚酯合成不饱和聚酯树脂的反应机理,讨论了二种树脂体系固化放热曲线不同的原因。     

On the nature of the active state of silver during catalytic oxidation of methanol

Under the applied high reaction temperatures (900 K) the Ag surface is restructured and a tightly held oxygen species is formed on the surface (O) apart from O atoms dissolved in the bulk (O). Methanol oxidation to formaldehyde proceeds through this O species as demonstrated by application of a variety of spectroscopic techniques.     

Oxidative coupling of methane on silver catalysts

Bulk silver catalysts were found to be active for the oxidative coupling of methane to ethane and ethylene if operated under oxygen-limited conditions at atmospheric pressure and at temperatures above 1020 K. The addition of small amounts of sodium phosphate as promoter increases markedly the C₂ selectivity (to values above 90%) and yield (>10%) by efficient suppression of reaction steps leading to total oxidation. Further improvement of the yields might be achieved by more appropriate reactor design.