TiSiW_(12)O_(40)/TiO_2催化合成辛酸乙酯

以正辛酸和乙醇为原料,用自制的环境友好固载杂多酸盐TiSiW12O40/TiO2为催化剂,催化合成辛酸乙酯。探讨TiSiW12O40/TiO2对酯化反应的催化活性,较系统地研究了醇酸量比,催化剂用量,反应时间诸因素对产率的影响。实验表明:TiSiW12O40/TiO2是合成辛酸乙酯的良好催化剂,在醇酸物质的量为1.3:1,催化剂用量为反应物料总量的2.0%,反应时间为1.5h,产率可达68.64%。     

Rheological Properties of Wormlike Micelles Formed in Aqueous Systems of 3‐Alkoxy‐2‐hydroxypropyl Trimethyl Ammonium Bromides in the Presence of Sodium Octanoate

The rheological properties of aqueous systems composed of each of the four homologous cationic surfactants (3‐alkoxy‐2‐hydroxypropyl trimethyl ammonium bromides, C_nHTAB, n = 12, 14, 16 and 18) in the presence of an anionic surfactant, sodium octanoate (SO), have been studied by using steady state and frequency sweep rheological measurements. The effects of surfactant concentration, hydrophobic chain length and temperature were investigated. In C₁₄HTAB solution, the viscosity shows shear thinning in the concentration range of C_C14HTAB >320 mmol/kg. Addition of SO promotes the micellar growth and results in the generation of wormlike micelles. Zero‐shear viscosity (η₀) of the binary surfactant system exhibits a maximum point in the investigated concentration range, suggesting the interaction between C₁₄HTAB and SO molecules is strongest at the optimal ratio of C₁₄HTAB with SO. The decrease in viscosity was attributed to be the transition from entangled wormlike micelles to branching micelles after the maximum point, cryo‐TEM images revealed the changes in the structure of the wormlike micelles.     

电感耦合等离子体原子发射光谱法测定辛酸铑催化剂中铂钯铅铁铜铝镍

准确测定辛酸铑催化剂中杂质元素含量,是判定产品是否合格的重要指标之一。以往常采用直流电弧发射光谱法(摄谱法)进行检测,但测定周期长,且重复性较差。用电感耦合等离子体原子发射光谱法(ICP-AES)测定辛酸铑催化剂中微量杂质元素时,辛酸铑催化剂样品中含有的大量有机组分和铑基体会对测定有严重干扰。实验采用反复滴加硝酸消解样品中有机组分,再用王水溶解盐类,选用合适背景点扣除的方式消除铑基体的干扰,建立了使用ICP-AES测定辛酸铑催化剂中0.001%~0.1%(质量分数)Pt、Pd、Pb、Fe、Cu、Al、Ni等7种微量杂质元素的方法。各元素在0.10~10.00μg/mL范围内与其发射强度呈线性关系,相关系数均大于0.9999;方法检出限(μg/mL)为0.075(Pt)、0.0033(Pd)、0.015(Pb)、0.0036(Fe)、0.010(Cu)、0.001(Al)、0.012(Ni)。实验方法用于测定辛酸铑催化剂样品中Pt、Pd、Pb、Fe、Cu、Al、Ni,结果的相对标准偏差为(RSD,n=7)为1.4%~9.6%。按照实验方法测定辛酸铑催化剂中Pt、Pd、Pb、Fe、Cu、Al、Ni,并与直流电弧发射光谱法的测定结果进行比对,结果相一致。     

Interpolymer radical coupling: A toolbox complementary to controlled radical polymerization

The current review focuses on the relevance and practical benefit of interpolymer radical coupling methods. The latter are developing rapidly and constitute a perfectly complementary macromolecular engineering toolbox to the controlled radical polymerization techniques (CRP). Indeed, all structures formed by CRP are likely to be prone to radical coupling reactions, which multiply the available synthetic possibilities. Basically, the coupling systems can be divided in two main categories. The first one, including the atom transfer radical coupling (ATRC), silane radical atom abstraction (SRAA) and cobalt-mediated radical coupling (CMRC), relies on the recombination of macroradicals produced from a dormant species. The second one, including atom transfer nitroxide radical coupling (ATNRC), single electron transfer nitroxide radical coupling (SETNRC), enhanced spin capturing polymerization (ESCP) and nitrone/nitroso mediated radical coupling (NMRC), makes use of a radical scavenger in order to promote the conjugation of the polymer chains. More than a compilation of macromolecular engineering achievements, the present review additionally aims to emphasize the particularities, synthetic potential and present limitations of each system.     

异丁醇/辛酸甲酯混合燃料预混层流火焰速度的研究

针对生物柴油与醇类混合燃料燃烧机理研究的需求,采用高速纹影光学诊断方法和定容燃烧弹系统试验研究了异丁醇/辛酸甲酯混合燃料的预混层流燃烧特性。测量了不同当量比和初始压力条件下的不同配比混合燃料—空气预混合气的层流燃烧火焰速度,火焰拉伸率以及马克斯坦长度。分析了燃烧初始条件及异丁醇掺混比例对混合燃料的无拉伸层流燃烧速度及火焰不稳定性的影响规律。结果表明:异丁醇/辛酸甲酯混合燃料的拉伸层流火焰传播速度和层流火焰燃烧速度随着当量比的增加先增加后减少,随着初始压力的增加而减小;马克斯坦长度随着当量比和初始压力的增加而减小;异丁醇掺混比例的增加加快了层流火焰燃烧速度,但使得火焰的不稳定性倾向增加。     

辛酸铑催化剂的消解及其铑含量的测定

提出了新的辛酸铑催化剂消解方法,重点研究了消解法的条件,比较了几种分解法及其铑含量测定的方法。结果表明：使用聚四氟乙烯消解罐,于160℃,12 mL HNO3-3 mL H2O2消解4 h,能完全消解0.1~0.2 g 样品。所用消解方法操作简便,Rh 不损失。采用硝酸六氨合钴重量法测定26.30%的铑含量,相对标准偏差0.099%。方法测定结果准确、精密。     

50%辛酰溴苯腈·二甲四氯异辛酯乳油的液相色谱分析

采用液相色谱法测定50%辛酰溴苯腈·二甲四氯异辛酯乳油,以C18柱为固定相,乙腈+水=85+15(v/v)为流动相,流速为1.0/min,检测波长为230nm。该方法的平均回收率分别为99.99%和100.03%,变异系数分别为0.12%和0.04%,标准偏差分别为0.03和0.01,相关线性系数分别为0.9998和0.9999。     

辛酰溴苯腈与2，4—D丁酯混用后对鸭跖草联合作用的研究

在温室盆栽条件下,林用等效线法评价辛酰溴苯腈与2,4－D丁酯用后的联合作用类型。结果表明,二者混用对3－4叶斯鸭跖草（Commelina communis L.)具有明显的增效作用。     

Chiral esters: Sex pheromone of the bagworm,Oiketicus kirbyi (Lepidoptera: Psychidae)

Gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone extract of female bagworms,Oiketicus kirbyi (Guilding), revealed five EAD-active compounds. Retention index calculations, GC-mass spectrometry in both full-scan and selected-ion monitoring modes and GC-EAD analyses of authentic standards identified the compounds as 1-methylbutyl octanoate (MBO), 1-methylbutyl nonanoate (MBN), 1-methylbutyl decanoate (MBD), 1-methylpentyl decanoate (MPD), and 1-methylbutyl dodecanoate (MBDD). Of these five chiral esters, MBD was most abundant in extracts and elicited the strongest antennal response. In field experiments in Costa Rica, (R)-MBD attractedO. kirbyi males, whereas (S)-MBD in combination with (R)-MBD inhibited response.R but notS enantiomers of MBO, MBN, and MBDD strongly synergized attraction to (R)-MBD. (S)-MBO and (S)-MBDD were inactive, whereas (S)-MBN was inhibitory. (R)-, (S)- and racemic MPD were inactive. Blends of (R)-MBD in ternary combination with either (R)-MBO and (R)-MBN or (R)-MBN and (R)-MBDD were as attractive as the five-ester blend. Five- and four-ester blends were equally attractive, suggesting redundancy of pheromone components for attraction of males. The multiple sex pheromone component blend of chiral esters inO. kirbyi may have evolved to maintain species-specific communication in bagworm communities of tropical Americas.     

32.7%溴苯腈辛酸酯乳油的研究与应用

溴苯腈间辛酰氯直接反应制备本腈辛酸酯，配制３２．７％溴苯腈辛酸酯乳油，并进行了毒性试验和田间应用试验。