Screening of medium composition for the free radical‐scavenging properties by Antrodia cinnamomea

The effects of nutritional conditions on the scavenging capacity on superoxide anion radical and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical of ethanolic extracts from filtrates of Antrodia cinnamomea were investigated in shake‐flask cultures. Culture medium significantly affected inhibition of superoxide anion generation and DPPH free radical scavenging activity. In contrast, both scavenging capabilities on superoxide anion radical and DPPH free radical were found to be greatly affected by varying the carbon source, the nitrogen source, the growth factors or the trace elements. The maximal inhibition of superoxide anion generation could be obtained when the culture medium compositions were: xylose, ammonium oxalate, nicotinic acid, NaH₂PO₄ and CuSO₄; while a maximal DPPH free radical scavenging activity could be achieved when the medium composition setting as: fructose, peptone, nicotinic acid, KH₂PO₄ and CaCl₂ (the scavenging effects on superoxide anion radical and DPPH free radical were increased to 96.3 ± 0.3% and 29.0 ± 1.0%, respectively). We proved that controlling the culturing conditions and modifying the composition of the medium can dramatically enhance the scavenging ability on superoxide anion radical and DPPH free radical of A. cinnamomea.     

Tribological characteristics of bisphenol S bis(diphenyl phosphate) as a high‐performance antiwear additive in lubricating greases at elevated temperature

Bisphenol S bis(diphenyl phosphate) (BSDP) was synthesised and characterised, and its tribological behaviours as additives in polyurea grease and lithium complex grease were evaluated for steel/steel contact at 200 °C. The results indicated that BSDP could dramatically reduce the friction and wear of sliding pairs in the base grease of polyurea, and the tribological performances of BSDP in polyurea grease were significantly superior to the normally used molybdenum disulfide‐based additive package. Furthermore, BSDP in polyurea grease has better tribological behaviour than that in lithium complex grease at a constant load of 100 N. X‐ray photoelectron spectroscopy analysis indicated that boundary lubrication films composed of Fe(OH)O, Fe₂O₃, Fe₃O₄ and FePO₄ compounds containing the P–O bonds and nitride compounds were formed on the worn surface, which resulted in excellent friction reduction and antiwear performance. Copyright © 2016 John Wiley & Sons, Ltd.     

碳酸二苯酯合成工艺的比较

碳酸二苯酯是一种用来合成许多有机化合物和高分子材料的重要的环境友好型的化工产品,本文对碳酸二苯酯合成的三种方法,即光气法、酯交换法和氧化羰基化法,进行了比较,介绍了氧化羰基化法的催化剂研究现状,论述了目前各种方法的研究现状及应用前景。     

1,2-二苯氧基乙烷的合成及工艺

采用水相体系直接合成得到高纯度的1,2-二苯氧基乙烷,在优化工艺条件下,以1,2-二溴乙烷和苯酚为基本原料,KOH为碱,1,2-二苯氧基乙烷摩尔收率达75%,产品气相色谱纯度达99%,且完成了10 kg/批的扩大合成实验评价,效果稳定。最优合成工艺为:反应时间25 h,w(KOH)=50%的水溶液,n(KOH)∶n(苯酚)∶n(1,2-二溴乙烷)=3.0∶3.0∶1.0,反应温度60℃。在该条件下,产物中杂质的生成量较少。     

Williamson反应合成取代二苯醚的清洁工艺

取代二苯醚(SDE)化合物是重要的精细化工中间体,它们可由Williamson反应合成。采用室温等离子液体(RIL)作为溶剂,可使Williamson反应的工艺清洁化。合成了一种RIL-1-丁基-3-甲基咪唑六氟磷酸盐(BMIMPF6),并以它为溶剂、K2CO3为催化剂,以取代硝基苯和苯酚为原料,通过Williamson反应合成了一系列SDE。研究了影响醚化反应的一些因素,如温度、时间、催化剂等,并在此研究基础上得出了较佳的醚反应条件为:物料/催化剂的摩尔比为1/1,温度为100℃,时间为1h。在此条件下所得SDE的收率为70%～93%,产品结构由1HNMR、13CNMR及MS所证实。另外,RIL至少可循环使用5次,而对SDE的收率及质量无明显影响,有利环保。     

有机碳酸酯清洁生产技术的研究进展

综述了近年来有机碳酸酯清洁生产技术及其所用催化剂体系的研究进展,重点对氧化羰基化法、酯交换法、尿素醇解法和CO2直接合成法等4种主要技术路线进行了介绍,同时对不同路线的工业化现状进行了总结,并对其工业化前景进行了展望。酯交换法和尿素醇解法将是今后有机碳酸酯清洁生产技术工业化发展的主流方向。     

双十四直链烷基二苯甲烷双磺酸盐的合成及性能

实验以二苯甲烷和酰氯为原料,在催化剂作用下,合成双酰基二苯甲烷,经克莱门森还原成双烷基二苯甲烷,以氯磺酸磺化得到双烷基二苯甲烷双磺酸,再以NaOH溶液中和,制成双直链烷基二苯甲烷双磺酸钠Gemini表面活性剂。在酰基化反应中,n(二苯甲烷):n(酰氯):n(无水氯化铝):n(硝基甲烷)=1:2.5:3.2:6.5,首先在常温下反应24 h,然后在70℃反应6 h,收率93.4%;在克莱门森还原反应中,n(酰基二苯甲烷):n(锌粉):n(浓盐酸)=1:10:50,反应温度105℃,反应时间8 h,收率91%;在磺化反应中,n(烷基二苯甲烷):n(氯磺酸):n(氯仿)=1:2:14,反应时间6 h,收率90%。对中间体进行了红外光谱、核磁共振氢谱分析,对最终产物进行了红外光谱、质谱分析.同时还测定了其水溶液的油水界面张力、表面张力及临界胶束浓度、泡沫性和乳化力。结果表明,产物具有7.22×10~(-3)mN/m的超低界面张力。     

二苯甲烷二异氰酸酯的绿色催化合成

研究了二苯甲烷二氨基甲酸甲酯（MDC）催化热分解生成二苯甲烷二异氰酸酯（MDI）的工艺过程。结果表明：在真空度保持O．097MPa下,适宜的反应温度为250℃,催化剂用量占MDC用量的6％,此条件下热分解约40min,二苯甲烷二氨基甲酸甲酯（MDC）的转化率可达到99．8％,二苯甲烷二异氰酸醣（MDI）的收率为70．3％。     

Antioxidant capacity and total phenolic content of selected plants from Turkey

A total of 28 different plants from different regions of Çanakkale, Turkey, were investigated for their antioxidant capacity and total phenol contents to find new potential sources of natural antioxidants. The antioxidant capacity of methanolic extracts prepared from various parts of plants was evaluated by both trolox equivalent antioxidant capacity (TEAC) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) assays, while the total phenolics were determined using the Folin‐Ciocalteu method. The TEAC values of plant extracts ranged in a large scale from 1472.36 to 17.61 μmol of trolox equivalents per g dry weight (dw), and EC₅₀ values (concentration at which 50% radical scavenging occurred) varied from 0.174 to 42.475 mg dw of plant, while the total phenol content of plant extracts ranged between 117.20 and 1.27 mg of gallic acid equivalents per g dw. There was a positive linear correlation between the TEAC and total phenols of plant materials (r = 0.916). The extracts of Hypericum perforatum, Arbutus andrachne and Paliurus spina‐christii showed higher antioxidant activities (both TEAC and DPPH assays). However, there was no clear relationship between TEAC and EC₅₀ values (r = 0.477) of plant extracts.     

聚醚醚酮后处理工艺的研究(Ⅰ)——红外光谱法监测二苯砜

本文提出以红外光谱法测定聚醚醚酮(PEEK)的丙酮和甲醇抽提液中二苯矾含量,监测PEEK的后处理工艺是否达到标准.实验表明,该法快速准确.