二氧化硅负载硅钨钼酸催化合成乙酰水杨酸

以水杨酸和乙酸酐为原料,以二氧化硅负载硅钨钼酸H4SiW6Mo6O40/SiO2为催化剂。探讨H4SiW6Mo6O40/SiO2对合成反应的催化活性,系统地研究了水杨酸和乙酸酐的物质的量比、催化剂用量、反应时间等因素对产物收率的影响。实验表明:H4SiW6Mo6O40/SiO2是合成乙酰水杨酸的良好催化剂,固定水杨酸用量为0.015 mol,在n(水杨酸)∶n(乙酸酐)=1∶2.0,催化剂用量为0.3g,反应时间15min的最佳条件下,乙酰水杨酸的收率可达75.1%。     

硅钨钼酸掺杂聚苯胺催化合成丁酮乙二醇缩酮

以H4SiW6Mo6O40（硅钨钼酸）/PAn（聚苯胺）为催化剂,通过丁酮和乙二醇反应合成了丁酮乙二醇缩酮。探讨了H4SiW6Mo6O40/PAn对缩酮反应的催化活性,较系统地研究了酮醇物质的量比、催化剂用量和反应时间诸因素对产品收率的影响。实验表明：在n（丁酮）∶n（乙二醇）=1∶1.9、催化剂用量为反应物料总质量的0.8%、带水剂环己烷的用量为6mL和反应时间1.0h的优化条件下,丁酮乙二醇缩酮的收率可达61.5%.     

硅钨钼酸掺杂聚苯胺催化合成丁醛乙二醇缩醛

以硅钨钼酸（H4SiW6Mo6O40）掺杂聚苯胺（PAn）的H4SiW6Mo6O40／PAn为催化剂．对丁醛和乙二醇合成丁醛乙二醇缩醛进行了研究。考察了原料量比、催化剂用量、反应时间、带水剂用量等对丁醛乙二醇缩醛产品收率的影响。实验表明：硅钨钼酸掺杂聚苯胺是合成丁醛乙二醇缩醛的良好催化剂。在n（丁醛）;n（乙二醇）为1：1.25,催化剂用量为反应物料总质量0．8％．环己烷为带水剂,反应时间1．0h的条件下,丁醛乙二醇缩醛产品收率为70．3％。     

硅钨钼酸掺杂聚苯胺催化合成丁醛1，2-丙二醇缩醛

自制了硅钨钼酸（H4SiW6Mo6O40）／PAn（聚苯胺）催化剂。通过丁醛和1，2-丙二醇为原料合成丁醛1，2-丙二醇缩醛，探讨了H4SiW6Mo6O40／PAn催化剂对缩醛反应的催化活性，较系统地研究了原料量比，催化剂用量，反应时间诸因素对产品收率的影响。实验表明：H4SiW6Mo6O40／PAn是合成丁醛1，2-丙二醇缩醛的良好催化剂，在n（丁醛）：n（1，2．丙二醇）=1：1．7，催化剂用量为反应物料总质量的1．0％，环己烷为带水剂，反应时间40min的优化条件下，丁醛1，2-丙二醇缩醛的收率可达78．5％     

二氧化硅负载硅钨酸催化合成丁醛1,2-丙二醇缩醛

以H4SiW12O40/SiO2为催化剂,丁醛和1,2-丙二醇为原料合成了丁醛1,2-丙二醇缩醛,用正交实验法研究了反应物料配比、催化剂用量、带水剂用量、反应时间等因素对反应的影响.结果表明,在n(丁醛)∶n(1,2-丙二醇)=1∶1.5,催化剂用量为反应物料总质量的0.6％,带水剂环己烷10mL,反应时间45min的...     

H3PW6Mo6O40/SiO2催化合成苹果酯

以自制二氧化硅负载磷钨钼酸作催化剂,以乙酰乙酸乙酯和乙二醇为原料合成苹果酯,探讨二氧化硅负载磷钨钼酸对该反应的催化活性,较系统地研究了酯醇物质的量比、催化剂用量、反应时间等因素对产物收率的影响.实验表明:H3PW6Mo6O40/SiO2是合成苹果酯的良好催化剂,在n(乙酰乙酸乙酯)∶n(乙二醇)=1∶1.4,催化剂用量...     

对甲苯磺酸催化合成丁酸正戊酯

以对甲苯磺酸为催化剂,正丁酸与正戊醇为原料催化合成丁酸正戊酯。较系统地研究了酸醇量比、催化剂用量、带水剂用量及反应时间等条件对收率的影响。结果表明：在固定正丁醇用量为0.2mol的情况下,在n（正丁酸）：n（正戊醇）=1：1.4,催化剂占反应物料总量2.5%,带水剂环己烷的用量为6mL,反应时间2.5h的优化条件下,产品收率可达83.3%。     

H4SiW12O40/ZrO2-Al2O3催化合成环己酮1,2-丙二醇缩酮

采用浸渍法制备ZrO2-Al2O3复合载体负载硅钨酸催化剂,并通过FT-IR、XRD对其进行了表征.以H4SiW12O40/ZrO2-Al2O3为催化剂,通过环己酮与1,2-丙二醇反应合成了环己酮1,2-丙二醇缩酮.较系统地研究了醇酮物质的量比、催化剂用量、带水剂用量及反应时间等条件对收率的影响.结果表明:H4SiW12O40/ZrO2-Al2O3催化剂是合成环己酮1,2-丙二醇缩酮的良好催化剂,固定环己酮用量为0.20mol,在n(环己酮)∶n(1,2-丙二醇)=1∶1.3,催化剂的用量占反应物量总质量的2.0％,带水剂环己烷的用量为8mL,反应时间75min的优化条件下,环己酮1,2-丙二醇缩酮的收率可达84.6％.     

分子筛MCM-48负载硅钨酸催化合成丁酮-1,2-丙二醇缩酮

报道了以分子筛MCM-48负载硅钨酸H4SiW12O40/MCM-48为催化剂,通过丁酮和1,2-丙二醇反应合成了丁酮-1,2-丙二醇缩酮。探讨了H4SiW12O40/MCM-48对缩酮反应的催化活性,较系统地研究了酮醇物质的量比、催化剂用量、反应时间诸因素对产品收率的影响。实验表明:H4SiW12O40/MCM-48是合成丁酮-1,2-丙二醇缩酮的良好催化剂,在n(丁酮)∶n(1,2-丙二醇)=1∶1.6,催化剂用量为反应物料总质量的0.6%,环己烷为带水剂,反应时间45 min的优化条件下,丁酮-1,2-丙二醇缩酮的收率可达91.9%。     

H3PW6Mo6O40/SiO2催化合成丁醛1,2-丙二醇缩醛

以H 3PW6Mo6O40/SiO2为催化剂,用丁醛和1,2-丙二醇为原料催化合成了丁醛1.2-丙二醇缩醛,正交实验法探讨得出的适宜反应条件为:固定丁醛用量0.2mol,丁醛与1,2-丙二醇的物质的量之比为1.0∶1.5,催化剂H3PW6Mo6O40/SiO2用量占反应物料总质量的0.8％,反应时间30min,带水剂环己烷的用量12mL.在该反应条件下,丁醛1.2-丙二醇缩醛的收率可达83.42％.     

6-氯和6-甲氧基嘌呤核苷的合成

以四乙酰呋喃核糖(Ⅰ)和6 氯嘌呤(Ⅱ)为原料,在对甲苯磺酸(TsOH)存在下,运用微波固态反应得到中间体2′,3′,5′ 三乙酰基 6 氯嘌呤核苷(Ⅲ),收率为80 1%。该中间体再用NH3/CH3OH和Na2CO3/CH3OH处理,分别合成了6 氯 9 β D 嘌呤核苷(Ⅳ)和6 甲氧基 9 β D 嘌呤核苷(Ⅴ),收率分别为78 8%和76 9%。Ⅳ和Ⅴ的总收率分别为63 1%和61 6%,结构经1HNMR和元素分析证实。最佳的缩合条件是n(Ⅰ)∶n(Ⅱ)=1∶1,m(TsOH)/m(6 氯嘌呤)=0 03,595W微波辐射4 5min,462W微波辐射1min和119W微波辐射0 5min;生成Ⅳ的氨解条件为室温反应2h,生成Ⅴ的碱解条件为回流5h。     

6-Trifluoromethylindole

6-Trifluoromethylindole was prepared by reductive cyclization of 2-nitro-4-trifluoromethylbenzyl cyanide. The indole was converted into the corresponding 3-aldehyde and 3-carboxylic acid.     

6-Trifluoromethyltryptamines

A series of 6-trifluoromethyltryptamines has been prepared from 6-trifluoromethylindole as the starting material. Conversion of the CF₃ group to CH₃ was observed during the reduction of some of these compounds with lithium aluminum hydride.     

Thermal and mechanical behavior of polyamide 6/polyamide 6I/6T blends

The thermal and mechanical properties of blends, obtained by mixing polyamide 6 (PA6) and an amorphous aromatic copolyamide G21 (ISO nomenclature PA 6I/6T), were investigated by differential scanning calorimetry, dynamic mechanical analysis, and mechanical tensile tests. Quenched blends show a single glass transition temperature; the T_g-composition trend was interpreted by means of the Gordon–Taylor equation. The half-time of crystal-lization decreases by increasing the G21 content and this indicates a depression of the overall crystallization rate. A small decrease in the equilibrium melting temperature of PA6 in the blends was observed; this finding suggests that the interaction parameter in PA6/G21 blends is probably very small. The dynamic mechanical analysis of crystallized blends suggests the presence of a homogeneous amorphous phase even if the crystallization of PA6 occurred. The tensile mechanical properties reveal that G21 acts as stiffener of PA6. The collected experimental data suggest that PA6 and G21 are miscible in the composition range investigated. © 1996 John Wiley & Sons, Inc.     

Pure component recovery from polyamide 6/6 6 mixtures by selective dissolution and reprecipitation

A selective dissolution/reprecipitation technique was applied for the effective recovery of Polyamide 6 (PA 6) and Polyamide 6 6 (PA 6 6) from their mixtures. The proposed process comprises mainly selective polyamide dissolution in an appropriate solvent at a specific temperature, reprecipitation of the polymer from the solution by addition of a nonsolvent, washing, and drying. A model mixture of virgin PA 6 and PA 6 6 pellets was initially tried, whereas in a following stage the selective dissolution technique was applied for the recovery of a PA‐copolymer layer from a three‐layered bottle end product also containing HDPE and EVA. End‐group analysis, dilute solution viscometry, and differential scanning calorimetry were used to assess the molecular weight preservation and crystallizability of the recycled polyamides. The recycled materials demonstrated excellent retention of the properties studied, although in the copolymer case, due to hydrolysis, a molecular weight decrease was detected, accompanied with a slight compositional shift, favoring the PA6 6 presence in the final product. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1924–1930, 2002     

Ölbindevermögen von Mineralozokeriten

Oil-bindung Capacity of Mineral Ozocerites It was attempted, by determining the slip point of the pastes obtained from different oils and mineral waxes, to find out and measure the influence of the quantity, viscosity of the oil, recrystallization tendency and homogenity as well as to characterise the oil-binding capacity of different hydrocarbon waxes. In view of the considerable rise in purity demands, the oil-binding capacity of highly refined microwaxes or mineral ozocerites was also investigated.     

Palmöl und Palmkernöl

Palm Oil and Palm Kernel Oil Adulteration of palm oil with palm stearin can be recognized by examining the ration of the triglycerides PPP to MOP, which lies in pure palm oil between 3.5 and 4.5 and is elevated in the case of adulteration. The content of palmitic acid and the solid fat content are additional indications. Adulteration of coconut and palm kernal oils with palm kernel olein is best recognized by measuring the iodine number (which is max. 11 for coconut oil and 19 for palm kernel oil) and also by the content of stearic, oleic and linoleic acids, the sum of which should not exceed 11.5% for coconut oil and 22% for palm kernel oil respectively. The content of triglycerides with carbon number 46 to 54 may additionally be used.