过渡金属氮化物催化性能研究进展

过渡金属氮化物具有类似于Pt族贵金属的催化性能得到了广泛的研究.综述了过渡金属氮化钼及助剂促进的氮化钼在加氢脱硫与脱氮、氨合成与分解、芳烃加氢和其他涉氢反应(如炔烃、烯烃加氢、丙酮缩合、肼的分解)中的应用,并介绍了其他金属氮化物(如氮化钒、氮化钴)在催化反应中的应用.     

水中致癌芳香胺的固相萃取-气质分析方法研究

采用固相萃取-气相色谱质谱法分析了水中24种致癌芳香胺的含量,结果表明,该方法的检出限低于0.36 μg/L。固相萃取的优化条件为：选用Envi-chromp固相萃取小柱,水样pH 8~10,二氯甲烷洗脱2次。绝大多数芳香胺的空白水样加标回收率在88.8%~111.8%之间,标准偏差为6.8%~9.9%。对浙江省13个饮用水源地的地表水进行检测,均未检出24种致癌芳香胺。降解实验表明,大多数芳香胺化合物在水中能稳定存在14 d以上。     

Effect of different aromatic amines on the crosslinking behavior and thermal properties of phthalonitrile oligomer containing biphenyl ethernitrile

To find a proper amine to promote the processability of phthalonitrile‐based composites, three different aromatic amines: 4‐aminophenoxyphthalonitrile (APN), 2,6‐bis (4‐diaminobenzoxy) benzonitrile (BDB) and 4,4′‐diaminediphenyl sulfone (DDS) were used as curing agents to investigate the crosslinking behavior and thermal decomposition behavior of phthalonitrile oligomer containing biphenyl ethernitrile (2PEN‐BPh). Differential scanning calorimeter (DSC) and dynamic rheological analysis were employed to study the curing reaction behavior of the phthalonitrile/amine blends and prepolymers. The studies revealed that BDB was the preferred curing agent and the preferred concentration of BDB was 3 wt %. The thermal properties of the 2PEN‐BPh polymers were monitored by TGA, and the results indicated that all the completely cured 2PEN‐BPh polymers maintained good structure integrity upon heating to elevated temperatures and these polymers could thermal stabilize up to over 550°C in both air and nitrogen atmospheres. Dynamic mechanical analysis (DMA) showed the glass transition temperature (T_g) exceeded 450°C when the 2PEN‐BPh polymer post cured at 375°C for 8 h. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

An efficient method for nitration of aromatic compounds over solid acid and polymer‐supported sodium nitrite

A variety of aromatic compounds are nitrated under heterogeneous conditions using a polymer‐supported hydrochloric acid, [P₄‐(VP)]HCl, with a polymer‐supported sodium nitrite, [P₄‐VP]NO₂, or sodium nitrite in ethanol at room temperature with high yields. This methodology is useful for nitration of activated aromatic compounds. In this procedure, the work‐up is very easy, and the spent polymeric reagent can be regenerated and reused. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Regioselective and green synthesis of nitro aromatic compounds using polymer‐supported sodium nitrite/KHSO4

Polymer supported reagents have become the subject of considerable and increasing interest as insoluble materials in the organic synthesis. Use of polymeric reagents simplifies routine nitration of aromatic compounds because it eliminates traditional purification. In this article, the use of readily available cross‐linked poly(4‐vinylpyridine) supported sodium nitrite, [P₄‐Me] NO₂, as an efficient polymeric nitrating agent in the presence of KHSO₄ is described. A good range of available aromatic compounds were also subjected to nitration in the presence of [P₄‐Me] NO₂/KHSO₄. This reagent is regioselective and chemoselective nitrating polymeric reagent for activated aromatic rings. In this procedure, the work‐up is easy, and the spent polymeric reagent is easily regenerated and reused. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

偏最小二乘光度法同时测定白油中单环及多环芳烃含量

白油中存在着单环芳烃和多环芳烃物质,其吸收光谱相互重叠,在测定波长260～300 nm范围内,采用偏最小二乘回归(PLS)法同时测定白油中单环芳烃和多环芳烃的含量,当残差平方和PRESS达到最小值时,确定PLS回归中二组分的主成分数均为4,分析结果表明,样品中单环芳烃和多环芳烃的回收率在93.73%～101.31%,线...     

超声波辅助萃取天然植物香料研究进展

超声波辅助萃取技术近年已经在天然植物香料萃取方面得到越来越广泛的应用。对超声波（溶剂法）萃取、超声强化超临界CO2萃取和超声-微波协同萃取在天然植物香料提取方面的最新应用及研究进展进行了总结,同时对超声波辅助萃取天然植物香料前景进行了展望。     

芳香族聚酯酰胺的合成方法研究

简述了聚芳酯和聚芳酰胺的优异特点,然而由于二者单独使用时存在某些不足,因此将二者进行共缩聚改性得到芳香族聚酯酰胺,它作为聚芳酯和聚芳酰胺的一种改性聚合物,兼有两者的优异性能;在多篇文献的基础上,综述了芳香族聚酯酰胺的几种比较常见的合成方法,低温溶液缩聚,界面缩聚,酯交换,混合法,还分别简要的剖析了几种合成方法的特点.由...     

一种纤维用新型聚乙二醇固-固相变储能材料

根据固-固相变材料的性质与结构特点,通过分子设计合成出了一种新型的芳香族四羟基化合物——4,4'-二苯基甲烷二异氰酸甘油酯(MTE),同时以4,4'-二苯基甲烷二异氰酸酯(MDI)-MTE为硬段,以聚乙二醇为相变单元和软段,通过原位聚合法制备出了一种聚乙二醇固-固相变储能材料(P-PCM)。利用红外光谱、核磁共振光谱、差示扫描量热法、动态热机械分析法研究了P-PCM的结构、相变行为及热稳定性,表明了P-PCM是一种新型的性能优异的相变材料。由于材料的刚性、可熔融和可溶解性,适合于纤维与织物的加工使用。     

工艺参数对水性聚氨酯分散体性能的影响

以甲苯二异氰酸酯(TDI)、自制聚酯二元醇为主要原料合成了水性聚氨酯分散体(WPUD),研究了投料方式、反应温度和反应时间、中和方式、乳化温度等工艺参数对NCO含量及WPUD性能的影响.结果表明,采用两步投料法,第一步温度控制在65～70 ℃、反应1 h,第二步温度控制在70～75℃、反应3 h;采用前中和工艺、乳化时...