壳聚糖与MAA接枝共聚反应及产物热性能研究

用硝酸铈铵引发壳聚糖(Cs)与甲基丙烯酸(MAA)接枝共聚，研究了接枝共聚反应产物组成与单体及引发剂浓度的关系，以及Cs接枝前后的热性能。结果表明，接枝共聚物的接枝率、接枝效率、均聚物含量，以及总转化率随单体及引发剂浓度的增加而呈现先增加后下降的趋势。同时，由于接枝聚合，使Cs大分子原来的结晶结构受到破坏，导致热稳定性有所下降。     

Preparation and photocatalytic activity of nano-sized nickel molybdate (NiMoO4) doped bismuth titanate (Bi2Ti4O11) (NMBT) composite

Various compositions of nano-sized (NiMoO₄)_x-doped Bi₂Ti₄O₁₁ (x = 0.01, 0.05, 0.1) composites have been prepared by chemical solution decomposition (CSD) method using triethanolamine (TEA) as complexing agent. Ni(II) is one of reactive species on the catalyst surface and Mo(VI) ion helps to compensate the charge of the lattice. The photocatalysts based on the above compositions have been tested for photobleaching of methyl orange (MO) solution under Hg-lamp. The prepared nanopowders are characterized by XRD, EDAX, UV–vis spectra, specific surface area (BET), zeta potential, ESR and HRTEM analyses. The average particle size of nickel molybdate-doped bismuth titanate lies around 30 ± 2 nm measured from TEM. Result shows nickel molybdate-doped bismuth titanate (NiMoO₄)_x(Bi₂Ti₄O₁₁)_1−x (NM_xBT_1−x; x = 0.01) composite is found to be more photoactive compared all the compositions studied except degussa P25 titania.     

氧化镁辐射接枝甲基丙烯酸甲酯的后效应和金属离子效应的研究

用共辐照电子束辐射接枝方法，研究了轻质氧化镁接枝甲基丙烯酸甲酯（ＭＭＡ）体系的辐照后效应和金属离子效应。通过对接校率、平均分子量的研究结果表明，后效应是接枝链上长寿命的自由基或离子在脱离辐照场后继续聚合的结果。ＣＵ２＋在非水体系户对均聚物具有较好的阻聚效果。     

明胶与甲基丙烯酸甲酯辐射接技共聚反应的研究

本工作采用~(60)Coγ射线辐照法,研究了明胶与甲基丙烯酸甲酯在水溶液中接枝共聚反应。实验结果表明:接枝率和接枝效率起先随着反应时间的增加而增加。但当反应温度和反应时间超过某值时接枝率和接枝效率反而下降。接枝侧链聚甲基丙烯酸甲酯具有较高的分子量(～10~5)。     

SnO2掺杂TiO2催化超声降解甲基橙溶液的研究

采用实验室合成的SnO2 掺杂TiO2 作为催化剂 ,研究了各种因素对甲基橙超声降解反应的影响。结果表明在SnO2 掺杂TiO2 催化剂作用下超声降解甲基橙的效果明显优于纯的TiO2 。 1.5 %掺杂量的催化剂 ,用量在 1.0～ 1.5g/L之间 ,超声波频率 2 5kHz,输出功率 1.0w/cm2 ,pH为 1.0时 ,甲基橙水溶液初始浓度 2 0mg/L的条件下 ,10 0min左右基本可全部降解 ,COD的去除率也可达到了 99.0 %。因此 ,SnO2 掺杂TiO2 催化超声降解有机污染物的方法具有很好的应用前景。     

A continuous photocatalysis system in the degradation of herbicide

The performance of both batch and continuous photo-catalytic reactors was studied to evaluate their capabilities in removing the sulfonyl urea herbicide of metsulfuron methyl (MM). It was found in a batch reactor that the addition of a small amount of powder activated carbon (PAC) significantly increased the rate of degradation of MM. The continuous photo-catalytic system resulted in 57% of MM removal. When a small dose of activated carbon was added in the photo-catalytic system, MM removal increased to 78–86% MM removal for retention times between of 5.25–21 min (corresponding to withdrawal rates of 10–40 mLmin⁻¹). In this study, the pseudo first order rate constants of a continuous photo-catalytic system revealed that shorter retention times were associated with lower rate constants. Solid phase micro extraction/gas chromatography (SPME/GC) results showed that high concentrations of MM were broken down to small volatile organic compounds (VOCs) by photo-catalytic oxidation. PAC adsorbed the photo-products and increased the degradation of MM.     

丙烯腈水解酯化法制丙烯酸甲酯过程中的气相色谱分析

报道了用总长2.1m,内径2mm的玻璃柱,内装填80cm Porapark P(50～80目)及130cm15％1,2-丙二醇己二酸聚酯+4％H_3PO_4(85％)/Chromosorb W AW DMCS(60～80目)的色谱柱,分离了合成过程中产生的二甲醚、甲醇、丙烯腈、丙烯酸甲酯、丙烯酸及β-甲氧基丙酸甲酯的全部组分,所需时间为12min,并以二氧六环为内标定量各组分,其相对标准偏差和相对误差均<2％,适合生产过程中控分析及成品分析。     

异丁醛异构为甲乙酮的研究(Ⅲ)

首次考察了在SAPO-5、SAPO-11、SAPO-34等磷酸硅铝分子筛及经磷改性的BZSM-5分子筛上异丁醛异构化的性能。在SAPO-11上,目的产物甲乙酮的选择性,与在BZSM-5上相近,可大于70％;BZSM-5经磷改性,异丁醛转化率无明显改变,而甲乙酮的选择性有较大提高,收率可达70％,SAPO-5及SAPO-34由于其孔道大小与反应物及目的产物分子大小不匹配,异丁醛转化率和甲乙酮选择性均甚低。     

甲醇脱水制二甲醚宏观反应速率的计算和测定

甲醇脱水制二甲醚宏观反应速率的计算和测定陈银飞，孙勤，葛忠华（浙江工业大学，杭州３１００１４）关键词：甲醇，二甲醚，宏观动力学１前言二甲醚作为一种甲基化剂，在制药、染料、农药等工业中有许多独特的用途。最近，有人提出并开发用二甲醚作为城市煤气或液化燃料...     

超声酶促合成维生素A棕榈酸酯

研究了超声辐照下,在有机溶剂中以固定化脂肪酶Novozym435催化合成维生素A棕榈酸酯。考察了影响合成维生素A棕榈酸酯反应的诸因素(溶剂、底物摩尔比、底物浓度、反应时间、酶量和超声功率),并优化了反应条件:在10mL的正己烷溶剂中,0.164g维生素A醋酸酯和0.32g棕榈酸,在酶与维生素A醋酸酯的质量比为1∶4的固定化脂肪酶Novozym435催化下,超声功率为90W,反应6h,酯化率可达82%。