生物燃料生产和技术发展趋势(下)

人们在积极探寻清洁汽、柴油燃料生产新工艺的同时,也在努力开发和利用矿物替代燃料,其中经挤性好、对大气污染小的乙醇和生物柴油备受青睐。燃料级乙醇和生物柴油生产正在向低成本方向发展。重点阐述车用燃料乙醇和生物柴油的国内外生产和应用现状以及技术发展趋势。     

红花注射液质量稳定性的生产工艺控制

通过对红花的提取工艺、醇沉实验、注射液的pH值选取、灭菌温度的控制、杂质的检查、增溶性试验、抗氧化测试、超滤试验等多方面的条件进行选择测试,探讨了红花注射液质量控制稳定性的方法。     

复杂山区水平绳索取心定向钻进聚合醇绿色防塌冲洗液研究

在西部艰险山区相关隧道及地下工程的勘察施工中,与传统垂直孔相比,水平定向绳索取心钻进勘察效率更高。在地质条件复杂、生态环境脆弱区,钻进过程中易出现塌孔、漏失等问题,要求所用冲洗液在保证流变性能的同时需具备抑制性强、无毒无害、绿色环保等特点。针对绳索取心水平定向钻进冲洗液性能问题,选择环保易降解、抑制性强的聚合物多元醇为主要研究对象,选择环保纤维素及纳米SiO₂,以提升其自身流变性能。所研制的聚合醇防塌冲洗液体系：2%PVA+0.5‰甲基纤维素MC-9+0.5‰纤维素羟烷基醚LE-5+0.1%SiO₂+0.3‰淀粉类降滤失剂DD-1+0.2%有机硅消泡剂DS-957+0.8%KCl,由环保型材料构成,流变性能良好,防塌抑制能力也可达到定向取心钻进工程要求,为解决水平绳索取心定向钻进中的冲洗液工艺技术难题提供了新思路,对类似工程具有借鉴意义与参考价值。     

洋葱抑菌基质抑菌包装纸的制备及其性能研究

针对馒头在储藏过程中容易发霉腐败的问题,以聚乙烯醇(PVA)为树脂基体,用洋葱汁作为主要抗菌基质制备洋葱基质母液,涂布到牛皮纸上制成抑菌包装纸,通过对被包装的馒头的霉变状况进行观察,从而判断洋葱基质对馒头所产生的抗菌作用。实验研究了涂布抗菌液后对抑菌纸的拉伸强度、水蒸气透过系数、氧气透过量的影响。研究结果表明:在相同的条件下,使用洋葱基质抑菌包装纸的试样霉变时间晚于空白试样,同时随着洋葱基质质量分数的增加,抗菌效果呈现出上升的态势;而当洋葱基质质量分数达到一定程度后,洋葱基质质量分数的增加对抗菌作用的加强效果趋于饱和;涂布包装纸的水蒸气透过系数和氧气透过量较牛皮纸有所降低,拉伸强度有所增强。     

PVA影响海藻酸钠复合水凝胶力学韧性和溶胀性能的研究

以醚化海藻酸钠(ESA)、丙烯酸(AA)、聚乙烯醇(PVA)为单体,N,N-亚甲基双丙烯酰胺为交联剂,过硫酸铵-亚硫酸氢钠为引发剂,水溶液法制备了醚化海藻酸钠-丙烯酸钠-聚乙烯醇复合高吸水性树脂(ESA/NaAA/PVA);采用红外光谱对产物进行了表征,观察了产物的微观相态结构,并测定了树脂的力学性能和溶胀性能.结果表明,体系组分的相容性和相区尺寸的大小与相区的组成有关,当ESA、AA的组成一定时,以w(ESA/NaAA):w(PVA)=88:12比例合成的树脂界面呈分布均匀状态;ESA/NaAA/PVA凝胶的韧性随PVA含量的增加而增大,PVA含量分别占总单体质量的3%、7%、10%、12%时,凝胶分别形变9%、14%、15%、15%时样品被破坏;当w(PVA)＜3.1%时,ESA/AA/PVA树脂在纯水和w(NaCl)=0.9%生理盐水中有较理想的溶胀能力.     

Oxidation,Redox Disproportionation and Chain Termination Reactions Catalysed by the Pd‐561 Giant Cluster

Redox disproportionation of benzyl alcohol to benzaldehyde and toluene catalysed by the Pd₅₆₁phen₆₀(OAc)₁₈₀ (phen=1,10‐phenanthroline) giant cluster 1 under anaerobic conditions was found, whereas in an O₂ atmosphere cluster 1 catalyses the oxidation of benzyl alcohol to benzaldehyde and inhibits further oxidation of the latter. A study of the AIBN‐initiated and non‐initiated oxidation of benzyl alcohol, sec‐butyl alcohol and styrene in the presence of cluster 1 revealed that cluster 1 performs three functions in the oxidation reactions: 1) catalysis of polar oxidation of the substrates with O₂, 2) termination of the chains of radical oxidation, and 3) catalysis of redox disproportionation.     

Gasoline Permeation Resistance of Containers of Polyethylene,Polyethylene/Modified Polyamide and Polyethylene/Blends of Modified Polyamide and Ethylene Vinyl Alcohol

An investigation of the gasoline permeation resistance of polyethylene (PE), polyethylene/modified polyamide (MPA), and polyethylene/blends of modified polyamide and ethylene vinyl alcohol (MPAEVOH) bottles is reported. The gasoline permeation resistance improves slightly after blending EVOH barrier resins in PE matrices during blow‐molding, wherein only broken and less demarcated EVOH laminas were found on the fracture surfaces of the PE/EVOH bottle. In contrast, much better permeation resistance and more clearly defined MPA and MPAEVOH laminas were found for PE/MPA and PE/MPAEVOH bottles, respectively. The gasoline barrier properties and MPAEVOH laminar structures of PE/MPAEVOH bottles improve and become more demarcated, respectively, as the MPA contents present in MPAEVOH resins increase. In fact, by using the proper composition, the gasoline permeation rate of PE/MPAEVOH bottles is about 450 and 3 times slower than that of the PE and PE/MPA bottles, respectively. These interesting gasoline barrier and morphological properties of PE, PE/MPA and PE/MPAEVOH were investigated in terms of melt shear viscosities and thermal properties of the base resins, and the chemical and physical amorphous phase structure present in their corresponding bottles.     

The elastic property of polyvinyl alcohol gel with boric acid as a crosslinking agent

The elastomers of polyvinyl alcohol gel were made from the polyvinyl alcohol polymer, with boric acid added as a crosslinking agent, in the mixed solvent of dimethyl sulfoxide and water. From the experimental results, the viscosity of polyvinyl alcohol solution is found to increase not only with an increment of boric acid content, but also with the temperature in the range of 70°C ∼ 100°C, although the viscosity is decreased in the range of 30°C ∼ 70°C. Moreover, the molecular mass between junctions of polyvinyl alcohol gel is calculated from the rubber elastic theory and found to be decreased with the increment of boric acid content. We also evaluated the values of Young's modulus of polyvinyl alcohol gel, E, E*, and the elastic parameters C₁ and C₂ of the Mooney‐Rivlin equation, according to Hook's law and theory of rubber elasticity. Based on these, the polyvinyl alcohol gel behaves as a good rubberlike elastic property. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3046–3052, 1999     

Study on the spatial resolution of a furfuryl alcohol‐negative photoresist using a holographic system

A negative photoresist was obtained from furfury alcohol using methylene dichloride as a solvent and trifluoracetic acid as a catalyst. A holographic assembly with a blue laser failed to give interference patterns. However, a periodic interference pattern was printed on a film of furfuryl alcohol resin using an ultraviolet laser with a coherent beam at 360 nm. The period of the pattern was reproduced throughout the film and resulted about 0.46 μm. Thus, the resin obtained was able to reach a resolution about 0.23 m. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1749–1751, 1999