Comparison of antimicrobial activities of polyacrylonitrile fibers modified with quaternary phosphonium salts having different alkyl chain lengths

A series of polyacrylonitrile fibers (PANF) modified with quaternary phosphonium salts having various alkyl chain lengths (C₁, C₂, C₆, C₈, C₁₂) were synthesized and compared for their antimicrobial activities by the improved shake flask method. The as‐prepared fibers were named MTPB‐PANF, ETPB‐PANF, HTPB‐PANF, OTPB‐PANF, and DTPB‐PANF, respectively. The representative microorganisms employed were Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa), and Candida albicans (C. albicans). Results from the current study showed that the alkyl chain length of quaternary phosphonium salts not only affected the synthesis of the fibers, but also impacted their antimicrobial activities. There was a rule that the longer the alkyl chain length, the more easily the quaternary phosphonium salts modify the fibers and the better the antimicrobial activities of the modified fibers. All the modified fibers exhibited good broad‐spectrum antimicrobial activities. Specifically, DTPB‐PANF exhibited an outstandingly high antimicrobial activity, which was nearly unaffected by the environmental pH (3–10). It can kill all the four pathogens in 15 min and had an excellent wash‐resistant property. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43689.     

我国洗涤用品原料LAS健康风险评估

通过对合成洗涤剂的重要原料LAS毒性资料进行全面的检索及整理,从毒代动力学、急性毒性、重复染毒毒性等9个方面综述了LAS毒性危害及相关毒性参数。在调查了中国家庭消费者洗涤用品使用方法与习惯及中国人群洗涤用品基本暴露参数的基础上,评估了LAS的人体暴露量。在危害评估及暴露评估的基础上,通过计算暴露限值(MOE)对LAS进行了风险表征描述。结果表明,LAS的MOE为497,家庭消费者通过洗涤用品暴露于LAS是安全的。     

微通道反应器中工业混合直链烷基苯磺酸盐的连续合成工艺研究

直链烷基苯磺酸是一种重要的阴离子表面活性剂,由其合成的直链烷基苯磺酸盐是价格低廉的表面活性剂之一,广泛应用于洗涤和三次采油等领域。以某煤制油企业的工业混合烯烃生产的直链烷基苯为原料,在微通道反应器中连续合成直链烷基苯磺酸,考察磺化温度、原料摩尔比以及磺化剂浓度等工艺条件对磺酸产物的影响规律,并与纯十六烷基苯磺化规律进行对比。研究发现混合直链烷基苯磺化过程中各个工艺条件对产品收率的影响较大。在反应温度为50℃,SO₃与LAB摩尔比为1.0∶1,停留时间为5.09 s条件下,最终产品中活性物含量可达到94.5%(质量)。同时,设计并搭建了微反应器小试平台,实现连续合成混合烷基苯磺酸盐,磺酸盐产品收率在90%以上,可为该工艺的工业应用提供技术支持。     

不同方法测定两种表面活性剂的临界胶束浓度

采用电导法及表面张力法分别测定了十二烷基硫酸钠(阴离子表面活性剂)和十二烷基三甲基氯化铵(阳离子表面活性剂)的临界胶束浓度,两种实验方法测得十二烷基硫酸钠的临界胶束浓度约为7.0×10-3mol·dm-3,十二烷基三甲基氯化铵的临界胶束浓度约为1.60×10-2mol·dm-3,两种方法所得结果一致。     

有机相酶促合成阿魏酸糖酯

利用酶促方法合成阿魏酸葡糖酯,对酶和有机溶剂进行了比较和筛选,并对影响阿魏酸葡糖酯产率的因素(酶量、反应时间、反应温度、底物比)进行了研究。结果表明,葡萄糖和阿魏酸乙烯酯(摩尔比4∶1)分别加入到体积比2∶1的无水吡啶和叔丁醇中,20 g/L Novozym 435脂肪酶,在220 r/min的空气振荡器中50℃反应72 h,产率能达到80.9%。     

Solvent-Assisted Crystallization of Fatty Acid Alkyl Esters from Animal Fat

An easy and efficient method for the separation of saturated and unsaturated fatty acid mono alkyl esters, prepared from animal fat, was developed. The most efficient separation was achieved by the use of solvents such as methanol and acetone at low temperatures. The dilution of the alkyl esters with 10 times the amount of solvent (10:1 v/w) and storage of the mixture for 4 h at ?22 °C could be defined as optimum conditions. After filtration of the saturated fraction at the corresponding temperature very pure fractions were obtained. For fatty acid methyl esters deriving from tallow, with an initial content of saturated fatty acids of almost 50 %, a saturated ester fraction with only 5 % unsaturated fatty acids and an unsaturated ester fraction with about 9 % of saturated fatty acids could be obtained. The solvent easily could be recovered by distillation. In addition fatty acid ethyl, 1‐propyl, 2‐propyl, 1‐butyl, tert‐butyl and 3‐methyl‐1‐butyl esters were prepared and separated into saturated and unsaturated fractions. All fractions were analyzed according to the fatty acid compositions and showed similar or slightly worse results compared to the methyl esters. The cold filter plugging points of the unsaturated fractions were measured, showing the lowest value for the unsaturated methyl ester fraction at ?26 °C. The fractionation with the use of solvents is an easy tool in order to obtain fatty acid alkyl esters with excellent cold temperature behavior out of animal fat.     

Synthesis and polymerizations of novel bisphosphonate‐containing methacrylates derived from alkyl α‐hydroxymethacrylates

The synthesis and polymerizations of four novel bisphosphonate‐containing monomers are reported. The monomers were synthesized from reaction of ethyl and tert‐butyl α‐bromomethacrylates with 3,3‐bis(diethoxyphosphoryl)propanoic acid or with tetraethyl 4‐hydroxybutane‐1,1‐diyldiphosphonate. Their thermal bulk polymerizations, photopolymerizations and copolymerizations with poly(ethylene glycol) methyl ether methacrylate were investigated. The homopolymerizations resulted in polymers with values of 25 000–83 000 g mol^?1; the copolymerizations yielded soluble polymers with 22–34% incorporation of the new monomers; the photopolymerizations gave some structure–reactivity correlation; and one of the homopolymers, upon hydrolysis of its bisphosphonate groups, could interact with hydroxyapatite. © 2013 Society of Chemical Industry     

马铃薯淀粉基烷基糖苷的合成

以马铃薯淀粉、乙二醇、十二醇为原料,对甲苯磺酸和助剂P为复合催化剂,采用转糖苷化反应合成烷基糖苷表面活性剂,探讨了各主要影响因素对合成反应过程及结果的影响。通过正交实验法优选出最佳工艺条件：糖苷化温度115℃;n(经折合的淀粉中葡萄糖单元): n(乙二醇): n(十二醇) : n(催化剂)=1∶5∶3∶0.01。在此条件下总糖苷收率为122.53%。     

Liquid chromatography–electrospray ionisation mass spectrometry method for the rapid identification of citrus limonoid glucosides in citrus juices and extracts

A rapid and selective liquid chromatography–electrospray ionisation mass spectrometry (LC–ESI-MS) method to screen citrus samples for limonoid glucosides and estimate their relative concentrations has been developed. This method utilises a phenyl stationary phase, whereas previous methods have relied on C-18. Samples may be analysed directly without treatment other than dilution. Peak areas from the extracted deprotonated molecular ion mass signals for individual limonoid glucosides were normalised against the sum of the areas to establish their relative concentrations. The method was successfully applied to the analysis of various juice, extracts, and liquid samples of partially purified limonoid glucosides.     

微波和脱皮处理菜籽对油中活性成分的影响

以高、中、低芥酸和硫甙含量菜籽为原料,微波和脱皮预处理后分别冷榨制油。结果表明,不同处理方式对同一品种菜籽的基本品质并无影响,但油中植物甾醇和维生素E含量均存在明显差异,且含量大小依次为低芥酸低硫甙菜籽〉中芥酸中硫甙菜籽〉高芥酸高硫甙菜籽。利用SPSS（统计产品与服务解决方案,Statistical Productand Service Solutions）方差分析,探讨4种不同处理方式与3种不同原料对菜籽油中维生素E和植物甾醇的影响。结果表明,不同处理方式对双低菜籽油中α、γ维生素E和△5-燕麦甾醇影响差异显著,对菜籽甾醇、菜油甾醇和β-谷甾醇影响不显著;同一种处理方式下,不同原料对维生素E和植物甾醇都存在显著差异。微波处理后油中维生素E和植物甾醇含量最高,且低芥酸低硫甙菜籽更适宜通过微波处理提高油的品质。