异丙苯在Cu-HMS分子筛上的催化氧化

以含Cu的中孔分子筛(Cu-HMS)为催化剂,研究异丙苯的催化氧化。研究发现,Cu-HMS催化剂的加入使异丙苯氧化的诱导期显著缩短。在75℃下,以Cu-HMS为催化剂,O2为氧化剂的纯异丙苯氧化反应,苯乙酮为主要副产物,反应的选择性和转化率都很高。当催化剂用量为1 5×10-4mol/ml时,反应8h后,异丙苯转化率为32 7%,目的产物的累积浓度(质量分数)为37 7%,选择性为99%;反应12h后,异丙苯转化率为42 4%,目的产物的累积浓度为46 3%,选择性为95 6%。     

Decreasing miscibility with greater heterogeneity in ternary polymer blend: poly(cyclohexyl methacrylate), poly(α‐methyl styrene) and poly(4‐methyl styrene)

A ternary blend system comprising poly(cyclohexyl methacrylate) (PCHMA), poly(α‐methyl styrene) (PαMS) and poly(4‐methyl styrene) (P4MS) was investigated by thermal analysis, optical and scanning electron microscopy. Ternary phase behaviour was compared with the behaviour for the three constituent binary pairs. This study showed that the ternary blends of PCHMA/PαMS/P4MS in most compositions were miscible, with an apparent glass transition temperature (T_g) and distinct cloud‐point transitions, which were located at lower temperatures than their binary counterparts. However, in a closed‐loop range of compositions roughly near the centre of the triangular phase diagram, some ternary blends displayed phase separation with heterogeneity domains of about 1 µm. Therefore, it is properly concluded that ternary PCHMA/PαMS/P4M is partially miscible with a small closed‐loop immisciblity range, even though all the constituent binary pairs are fully miscible. Thermodynamic backgrounds leading to decreased miscibility and greater heterogeneity in a ternary polymer system in comparison with the binary counterparts are discussed. © 2003 Society of Chemical Industry     

二苯基环己基甲醇的合成

以环己基苯甲酮和溴苯为原料,合成了二苯基环己基甲醇。探讨了影响反应的各种因素,并找到了较好的合成条件。     

Effect of natural antioxidants in virgin olive oil on oxidative stability of refined,bleached, and deodorized olive oil

The factors influencing the oxidative stability of different commercial olive oils were evaluated. Comparisons were made of (i) the oxidative stability of commercial olive oils with that of a refined, bleached, and deodorized (RBD) olive oil, and (ii) the antioxidant activity of a mixture of phenolic compounds extracted from virgin olive oil with that of pure compounds andα-tocopherol added to RBD olive oil. The progress of oxidation at 60°C was followed by measuring both the formation (peroxide value, PV) and the decomposition (hexanal and volatiles) of hydroperoxides. The trends in antioxidant activity were different according to whether PV or hexanal were measured. Although the virgin olive oils contained higher levels of phenolic compounds than did the refined and RBD oils, their oxidative stability was significantly decreased by their high initial PV. Phenolic compounds extracted from virgin olive oils increased the oxidative stability of RBD olive oil. On the basis of PV, the phenol extract had the best antioxidant activity at 50 ppm, as gallic acid equivalents, but on the basis of hexanal formation, better antioxidant activity was observed at 100 and 200 ppm.α-Tocopherol behaved as a prooxidant at high concentrations (>250 ppm) on the basis of PV, but was more effective than the other antioxidants in inhibiting hexanal formation in RBD olive oil.o-Diphenols (caffeic acid) and, to a lesser extent, substitutedo-diphenols (ferulic and vanillic acids), showed better antioxidant activity than monophenols (p- ando-coumaric), based on both PV and hexanal formation. This study emphasizes the need to measure at least two oxidation parameters to better evaluate antioxidants and the oxidative stability of olive oils. The antioxidant effectiveness of phenolic compounds in virgin olive oils can be significantly diminished in oils if their initial PV are too high.     

微波辐射对甲苯磺酸催化合成乙酸环己酯

以冰醋酸和环己醇为原料 ,环已烷为带水剂 ,对甲苯磺酸作催化剂 ,采用微波辐射技术 ,在常压下直接合成乙酸环己酯。最适宜反应条件为 :n(环己醇 )∶n(乙酸 ) =1 5∶1 0 ,对甲苯磺酸用量 0 2 0 g ,带水剂用量 5mL ,微波功率 5 95W ,辐射时间 15min ,产率达 97%以上     

Solid-state NMR studies on phase behavior and motional mobility in binary blends of polystyrene and poly(cyclohexyl methacrylate)

The phase behavior and motional mobility in binary blends of polystyrene (PS) and poly(cyclohexyl methacrylate) (PCHMA) have been investigated by solid state ¹³C NMR techniques. The blend miscibility has been studied by examining the ¹H spin-relaxation times in the laboratory frame (T₁^H) and in the rotating frame (T_1ρ^H) for the PCHMA/PS blends with various compositions and pure components. The T_1ρ^H results show that PCHMA and PS are intimately mixed at the molecular level within the blends at all compositions. In addition, according to the results of carbon T_1ρ relaxation time measurements, we conclude that mixing is intimate enough to cause a reduction in local chain mobility for PS, but an increase in side chain mobility for PCHMA.     

二苯胺甲烷磺酸盐催化合成乙酸环己酯

以二苯胺甲烷磺酸盐为催化剂，对乙酸与环己醇间的酯化反应进行了研究。考察了反应时间、催化剂用量、醇酸摩尔比和带水剂用量等对乙酸环己酯收率的影响。结果表明反应的较佳条件：当乙酸用量为0．1mol时，醇酸摩尔比为1．3，二苯胺甲烷磺酸盐用量为0．5g（约2mmol），带水剂环己烷用量8mL，反应30mi。后酯收率达96．4％，催化剂重复使用5次仍保持较高活性。产品经折射率、IR光谱进行了表征。     

格列喹酮合成工艺研究

以4-[(4,4-二甲基-7-甲氧基-1,3-二氧代-异喹啉基)乙基]苯磺酰胺和环己异氰酸酯为原料经一步反应合成目标产物格列喹酮,通过单因素和正交试验分别研究了反应中各个影响因素的较佳反应条件,最终确定了一条合成格列喹酮的较佳工艺路线,反应的总收率平均为85.52%.     

双核中性镍催化剂的合成及催化乙烯聚合研究

经烷基化、甲酰化、Schiff碱缩合反应，制得两种水杨醛亚胺配体(7)和(8)，并与 trans［NiCl(Ph)(PPh₃)₂］ 反应合成了两种中性镍配合物：(9){［［O-(3-Cyclohexanyl)(5-CH₃)C₆H₂-ortho-C(H)=N-2,6-C₆H₃(i-Pr)₂］Ni(Ph₃P)(Ph)］₂CH₂}和(10){［［O-(3-Cyclohexanyl)(5-Cl)C₆H₂-ortho-C(H)=N-2,6-C₆H₃(i-Pr)₂］Ni(Ph₃P)(Ph)-2-CH₂}，以GC-MS,1H NMR对中间产物及配合物进行了表征.在Ni(COD)₂的助催化作用下，配合物(9)和(10)能有效催化乙烯聚合.在8.0×105　Pa的压力下，配合物(9)的最高活性可达5.34×105 g /(mol·h)，聚乙烯相对分子质量和相对分子质量分布分别为5.26×104和 2.39.配合物(10)的最高活性可达5.74×105g /(mol·h)，聚乙烯相对分子质量和相对分子质量分布分别为8.61×104和2.81.     

氧化石墨烯在萘氧化中的作用研究

石墨烯在催化领域的应用越来越受到人们的重视。本文构建了萘—叔丁基过氧化氢（TBHP）—氧化石墨烯的催化氧化体系,研究氧化石墨烯在萘氧化过程中的作用。考察了氧化石墨烯种类、溶剂种类、氧化剂含量、石墨烯用量、反应温度、反应时间等因素对萘氧化反应的影响。实验结果表明氧化石墨烯的引入可以提高萘的转化率和1,4-萘醌收率; 当萘用量为100mg,氧化剂（TBHP）2.4mL,氧化石墨烯RGO（10wt%）20mg,反应溶剂为乙酸（1.2mL）,反应温度100℃,反应时间22h 时,得到了较优的反应结果。在此基础上,初步探讨了氧化石墨烯对萘氧化的作用机理。