BDP阻燃PC/ABS及其纳米复合材料的阻燃性和热降解动力学

采用双螺杆挤出机挤出造粒制备了苯基双酚A二磷酸酯(BDP)阻燃的聚碳酸酯(PC)/丙烯腈-丁二烯-苯乙烯(ABS)、PC/ABS有机蒙脱土(OMMT)和PC/ABS有机改性纳米二氧化(SiO2)3种复合材料,采用热重分析探讨了PC/ABS/BDP , PC /ABS/BDP/OMMTPC/ABS/BDP/SiO2复合材料的热降解动力学行为,以此分析其阻燃性能与热降解行为的关系。结果表明,加入纳米材料后,在质量损失8%以前,PC/ABS/BDP/OMMT和PC/ABS/BDP/SiO2纳米复合材料的活化能均低于PC/ABS/BDP的活化能,但质量损失8%以后,PC/ABS/BDP/OMMT和PC/ABS/BDP/SiO2复合材料的活化能均高于阻燃PC/ABS。在质量损失5%-75%范围内,PC/ABS/BDP/OMMT和PC/ABS/BDP/SiO2平均活化能分别为139.39KJ/mol和144.17KJ/mol,均高于PC/ABS/BDP的平均活化能(104.87 kJ /mol),说明添加纳米材料后,由于BDP与OMMT或SiO2的协同阻燃作用,降低了材料的热降解速率,增大了材料的热稳定性,这与氧指数测试、UL94V阻燃性能及热重分析得出的结沦一致。     

GC/MS法分析苯硫代膦酰二氯样品中的杂质

采用美国Finnigan公司最新型号的色质联用仪GC/DSQ,定性分析了苯硫代膦酰二氯合成产品。确定了其中杂质的主要成分二苯硫代膦酰氯,并用简单的面积归一化法算出了产品和杂质的大致含量,为下一步的研究工作指明了方向。     

丙二醇苯醚的工业合成

阐述丙二醇苯醚的工业合成工艺路线和设备的选择。     

Fate of fertilizer nitrogen applied to wheat under simulated mediterranean environmental conditions

Triticum aestivumThe fate of fertilizer nitrogen applied to dryland wheat was studied in the greenhouse under simulated Mediterranian-type climatic conditions. Wheat, L., was grown in 76-cm-deep pots, each containing 50–70 kg of soil, and subjected to different watering regimes. Two calcareous clay soils were used in the experiments, Uvalde clay (Aridic Calciustoll) and Vernon clay (Typic Ustochrept). Fertilizer nitrogen balance studies were conducted using various¹⁵N-labeled nitrogen sources, including ammonium nitrate, urea, and urea amended with urea phosphate, phenyl phosphorodiamidate (a urease inhibitor), and dicyandiamide (a nitrification inhibitor). Wheat yields were most significantly affected by available water. With additional water during the growing period, the recovery of fertilizer nitrogen by wheat increased and the fraction of fertilizer nitrogen remaining in the soil decreased. In the driest regimes, from 40 to 65% of the fertilizer nitrogen remained in the soils. In most experiments the gaseous loss of fertilizer nitrogen, as estimated from unaccounted for¹⁵N, was not significantly affected by water regime. The¹⁵N not accounted for in the plant and the soil at harvest ranged from 12 to 25% for ammonium nitrate and from 12 to 38% for regular urea. Direct measurement of labeled ammonia loss from soil indicated that ammonia volatilization probably was the main N loss mechanism. Low unaccounted-for¹⁵N from nitrate-labeled ammonium nitrate, 4 to 10%, indicated that N losses due to denitrification, gaseous loss from plants, or shedding of anthers and pollen were small or negligible. Amendment of urea with urea phosphate to form a 36% N and 7.3% P product was ineffective in reducing N loss. Dicyandiamide did not reduce N loss from urea presumably because N was not leached from the sealed pots and denitrification was insignificant. Amendment of urea with 2% phenyl phosphorodiamidate reduced N loss significantly. However, band placement of urea at as 2-cm soil depth was more effective in reducing N loss than was amendment of broadcast urea with phenyl phosphorodiamidate.     

Preference for novel flavors in adult Norway Rats ( Rattus norvegicus).

The authors fed rats 1 of 2 distinctively flavored, roughly equipalatable diets for 3 days then offered them an ad libitum choice between the 2 diets. For 3 days, subjects exhibited a reduced relative intake of whichever diet they had previously eaten (Experiment 1). Such reduction in relative intake was as effective as a toxicosis-induced conditioned aversion in determining subjects' food choices (Experiment 2). The strength of exposure-induced reduction in relative intake did not depend on similarity of the 2 diets offered for choice either to each other or to subjects' maintenance diet (Experiment 3) but did require continuous exposure to a diet (Experiment 4). These experiments provide the first evidence of a robust, exposure-induced decrease in food preference in rats lasting for days rather than minutes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

耐高温低磨耗聚苯酯改性聚四氟乙烯

本文介绍了特种工程塑料聚苯酯的性能、用途以及聚苯酯改性聚四氟乙烯(PTFE)塑料的加工、性能及应用情况     

Treatment performance of volatile organic sulfide compounds by the immobilized microorganisms of B350 group in a biotrickling filter

BACKGROUND: In this work, the feasibility of biodegradation and the removal performance of sole and mixed odorous vapors, such as dimethyl disulfide (DMDS), methyl phenyl sulfide (MPS), and ethanethiol (EtSH) in an EtSH‐acclimated biotrickling filter seeded with commercially available B350 microorganisms, were investigated. RESULTS: Removal efficiencies (REs) for DMDS as a sole substrate were evaluated under different inlet concentrations and empty bed residence times (EBRT), 100% RE was achieved at concentration below 0.4 g m^?3 at EBRT 110 s. In addition, 100% RE was obtained for binary EtSH and DMDS (3:2) at the same EBRT. According to the Michaelis–Menten type kinetic equation, the maximum removal rates (V_max) were calculated as 28.7 and 13.9 g m^?3 h^?1 for DMDS and MPS as sole substrate, respectively, while V_max was 22.1 and 10.1 g m^?3 h^?1 for DMDS and MPS in the presence of EtSH and EtSH‐DMDS mixture, respectively. After 5 and 20 days starvation, the re‐acclimation times were only 2 and 8 days, respectively, for the binary system. An EtSH:DMDS:MPS (3:2:1) ternary mixture was removed efficiently by the rebooted system after starvation. CONCLUSION: The proposed system can be applied to cost‐effectively decompose a mixture of volatile organic sulfide compounds at pilot scale. Copyright © 2011 Society of Chemical Industry     

Bromophenol Distribution in Salmon and Selected Seafoods of Fresh- and Saltwater Origin

Analysis of saltwater Pacific salmon (Onchorynchus sp.) showed that sufficient concentrations of bromophenols were present in saltwater salmon to provide sea-, brine-, or iodine- like flavor notes, but the compounds were virtually absent in spawning run ocean and prime condition Great Lakes freshwater salmon. Octanol/water partition coefficients revealed that bromophenols would be readily absorbed by fish from the diet. Analysis of marine fish, crustaceans, and molluscs also revealed notable concentrations of bromophenols in all samples. Only sporadic, low concentrations of bromophenols were found in freshwater fish. The data support the hypothesis that simple bromophenols are widely distributed in marine species via the food chain.     

肉香味香精的热反应制备

利用均匀设计安排有丝氨酸参与的热反应制备肉香味香精,通过用5个细化指标对样品评分后,多项式回归拟合该反应的回归方程,据此方程分析各因素及交互作用对反应体系产香的影响,结合回归方程和实际情况找出最佳的反应条件为:丝氨酸2.0g、丙氨酸1.2g、半胱氨酸3.2g、木糖10.526g、I+G 2.245g、谷氨酸2.547g、水含量为80%、系统pH值=5.32,在113℃下反应53min。     

对甲氧乙基苯基缩水甘油醚的合成研究

4-(2-甲氧乙基)苯酚与环氧氯丙烷在碱性催化剂中进行缩合反应得到对甲氧乙基苯基缩水甘油醚．结果表明，当用氢氧化钾为催化剂，n(环氧氯丙烷)：n(4-(2-甲氧乙基)苯酚)=2，反应时间为5h，水为溶剂，回流反应，产物产率为87．2％。