Characteristic properties of cutting fluid additives derived from half esters of dimer acids

A number of half esters were prepared from the reaction of alcohols with dimer acids and screened for anti-rust properties and antimicrobial activity in spent coolants of water-based cutting fluids. Aqueous solutions of triethanolamine salts with lower-alcohol half esters of dimer acid showed good anti-rust properties for water-based cutting fluids.     

Characteristic properties of cutting fluid additives derived from the derivatives of ricinoleic acid polymers

A number of esters were prepared from the reaction of acid chlorides with ricinoleic acid polymers and screened for anti-rust properties and antimicrobial activity in spent coolants of water-based cutting fluids. Aqueous solutions of triethanolamine salts with decanoic acid, undecanoic acid and oleic acid esters of ricinoleic acid dimer, trimer, tetramer and hexamer showed good anti-rust properties for water-based cutting fluids. Dehydrates of ricinoleic acid polymers also showed good anti-rust properties for water-based cutting fluids.     

Characteristic properties of cutting fluid additives derived from the adducts of diamines and acid chlorides

A number of N,N′-diacylalkyldiamines were prepared from the reaction of acid chlorides with 1,8-diaminooctane and 1,12-diaminododecane and screened for anti-rust properties and antimicrobial activity in spent coolants of water-based cutting fluids. Aqueous solutions of N,N′-dihexanoyl-1,8-diaminooctane and N,N′-isobutyroyl-1,12-diaminododecane showed good anti-rust properties for water-based cutting fluids. Aqueous emulsions of N,N′-dibutyroyl-, dipentanoyl-, dihexanoyl- and dioctanoyl-1,12-diaminododecane showed good lubricities and antimicrobial activity for water-based cutting fluids.     

N-acyl-L-leucines of biologically active uncommon fatty acids: Synthesis and antibacterial activity

The effect of structural variation in the fatty acid chain on the antibacterial activity ofN-acyl-L-leucines was investigated. PureN-acyl leucines of some structurally different and biologically active uncommon fatty acids were synthesized for the first time and tested for antimicrobial activity.N-Stearoyl-,N-oleoyl- andN-ricinoleoyl leucines were also evaluated for comparison. TheN-acyl leucines exhibited greater activity in acid form than the methyl ester form and against gram positive bacteria than gram-negative bacteria. The presence of a cyclopropane or a hydroxy group or unsaturation in the acyl chain increased the antibacterial activity. Shifting the hydroxyl group toward the amide linkage resulted in a diminished effect on the antibacterial activity.     

Synthesis,characterization and antibacterial activity of quaternized <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">O</Emphasis>-(2-carboxyethyl) chitosan

N,O-(2-carboxyethyl)chitosan (N,O-2-CEC) was prepared from chitosan with 3-chloropropionic acid as modifying agent and NaOH as catalyst. Different quaternary ammonium groups were introduced into N,O-2-CEC by the reaction between N,O-2-CEC and different 2,3-epoxypropyl trialkyl ammonium chlorides in the presence of 25% NaOH aqueous solution, and obtained different quaternized N,O-2-carboxyethyl chitosans (QCECs). Structures of QCECs were characterized by FT-IR, ¹HNMR and gel permeation chromatography (GPC). Antimicrobial activity of QCECs was evaluated against a gram-negative bacterium Escherichia coli and a gram-positive bacterium Staphylococcus aureus. Compared with N,O-2-CEC and quaternized chitosans, the QCECs had much stronger antimicrobial activity, which increased with increasing chain length of the alkyl in the quaternary ammonium groups. The presence of benzyl in quaternary ammonium groups could endow QCECs with much better antimicrobial activity.     

水溶性防锈添加剂的合成

以三乙醇胺、硼酸、十二烯基丁二酸为原料合成高性能防锈剂硼酸三乙醇胺酯十二烯基丁二酸酰胺,产品具有很好的防锈能力。     

汽车车架涂装前处理工艺研究

介绍了车架电泳涂装前处理的工艺:即钢板酸洗、工序防锈、脱脂、表面调整、磷化。并分析了不同前处理工艺对涂装效果的影响,总结了车架电泳涂装前处理的优缺点。     

Environmentally acceptable drag-reducing surfactants for district heating and cooling

The aim of this work was to find drag-reducing surfactants for both district heating and cooling that are environmentally more acceptable than the organic salts of quaternary ammonium compounds that so far have dominated this application. Vortex inhibition of test solutions in glass beakers has been used to screen a large number of surfactant mixtures, various electrolytes, and temperatures. For the most interesting products, the pressure drop in a test loop was measured at various flow rates and temperatures.N-cetyl sarcosinate andN-stearyl betaine, the latter together with Na-dodecylbenzene sulfonate, give good drag reduction (DR) properties at 65–100 and 45–85°C, respectively. The sarcosinate is sensitive to pH changes, whereas the betaine-sulfonate complex is more robust. Ethoxylates of oleic acid monoethanolamide show good DR properties at 0–25°C. At an increased salt concentration, a mixture of this surfactant with an ethoxylated oleyl alcohol worked well. At a still higher salt concentration, e.g., sea water, a combination ofN-cetyl betaine and alkylbenzene sulfonate showed DR.     

Water-soluble metalworking fluid additives derived from the derivatives of 3-mercaptopropionic acid

A number of derivatives of thiocarboxylic acid were prepared from the reaction of 3-mercaptopropionic acid and alkyl halides, and screened for anti-rust properties in water-soluble metalworking fluids. Aqueous metalworking fluids containing octylthiopropionic acid or hexylthioacetic acid showed excellent anti-rust properties for water-soluble metalworking fluids.     

Surface Properties and Biological Activity of Select Cationic Surfactants

A series of cationic surfactants, N-(decyl N-tri-ethanol ammonium Bromide) (C₁₀), N-(dodecyl N-triethanol ammonium Bromide) (C₁₂), N-(hexadecyl N-triethanol ammonium Bromide) (C₁₆) were synthesized. These compounds have been evaluated by studying their surface properties, surface parameters, biodegradability and antimicrobial and antifungal activities.

Preparation and surface-active properties of telomer-type anionic surfactants from maleic anhydride

Maleic acid alkyl ester and N-alkyl maleamic acid monomers (R_nMa and R_nMaAm; n is alkyl chain length; n=6, 8, 10, 12, 14) were synthesized by the reaction of maleic anhydride with alkyl alcohol or alkylamine. The telomerization of R_nMa or R_nMaAm in the presence of alkanethiol as a chain transfer agent gave telomer-type anionic surfactants (xR_nMa, xR_nMaAm; x is total average number of alkyl chains; x=2.8–3.3) having multialkyl chains and multicarboxylate groups. Their surface-active properties were investigated by several techniques such as surface tension, foaming property, and emulsification power measurements. Critical micelle concentrations (CMC) of xR_nMa were 1/110–1/14 of those of R_nMa with the same alkyl chain length. xR_nMa and xR_nMaAm gave higher efficiencies in lowering the surface tension than R_nMa and R_nMaAm in aqueous solutions. In particular, the surface tension of 3.2R₁₂MaAm was 24.4 mN m⁻¹ at the CMC. Foaming abilities and foam stabilities of xR_nMa and xR_nMaAm were higher than those of R_nMa and R_nMaAm. The addition of 300 ppm of Ca²⁺ to the aqueous solutions rendered the telomers less surface active. Shaking the aqueous solutions of telomers with toluene emulsified them. The highly stable oil-in-water type emulsion was formed by using 3.0R₁₀MaAm and 3.2R₁₂MaAm, and the degree of emulsification was kept at a level of about 80% after 60 min of standing. Thus, telomer-type surfactants showed excellent surface activities that were superior to the corresponding monomers as well as to conventional surfactants. The relationship between alkyl chain length of the telomers and the properties of surface tension, foaming, and emulsification was unclear.     

整机产品防锈工艺研究

为提高整机产品的耐腐蚀性能,三一港机工艺院会同集团精益质量总部进行了防锈材料筛选试验,旨在通过对多种防锈材料的防锈性能试验对比,优选出性价比最佳的防锈材料,并在产品上进行使用,以提高产品整体耐蚀性能.     

水性纳米改性苯丙防锈底漆的研制

本试验选用无皂聚合工艺制备的水性苯丙防锈乳液为基料,氧化铁红与三聚磷酸铝组成防锈体系,添加纳米SiO_2浆料,制备的水性纳米改性苯丙防锈底漆性能达到溶剂型醇酸防锈涂料的水平,并分析了乳液、防锈颜料、纳米SiO_2对水性苯丙防锈底漆性能的影响。     

Surface activities,biodegradability and antimicrobial properties of glucosamine derivatives containing alkyl chains

Three series of D-glucosamine derivatives containing an alkyl chain with 8 to 14 atoms, methyl 2-acylamino-2-deoxy-D-glucopyranosides,n-alkyl 2-acetylamino-2-deoxy-D-glucopyranosides andn-alkyl 2-amino-2-deoxy-D-glucopyranoside hydrochlorides, were synthesized, and their surface properties (such as surface tension, critical micelle concentration (CMC), dynamic surface tension and foaming properties), biodegradability and antimicrobial activities were evaluated.n-Alkyl 2-amino-2-deoxy-D-glucopyranoside hydrochlorides containing C8 to C12 carbon chains showed surface activities, a CMC and excellent foaming properties. The α-anomers showed a slightly lower CMC than the β-anomers, indicating less hydrophilicity of the α-anomers. On the other hand, glucosamine derivatives containing amide groups showed poor surface activities in water due to their lower solubilities in water. All glucosamine derivatives containing alkyl chains were biodegraded as well as conventional ethoxylated nonionics by activated sludge from the municipal sewage treatment plant. Methyl 2-acylamino-2-deoxy-D-glucopyranosides andn-alkyl 2-amino-2-deoxy-D-glucopyranoside hydrochlorides showed a broader spectrum of antimicrobial activity than the correspondingn-alkyl glucopyranosides. Among them the C12 derivatives showed the best results.     

The partial oxidation of C4–C6 alkanes to maleic anhydride, 2-methyl maleic anhydride, and acetic acid over MoVO catalysts

Alkanes such as iso-butane, n-pentane, and cyclohexane have been converted effectively to maleic anhydride, 2-methyl maleic anhydride, and acetic acid over MoVO catalysts below 330 °C. In order to explore the possible reaction pathways, the oxidation of iso-butene, cyclohexene, 2-methyl-1-propanol, tert-butanol, and 2-methylacrylic acid were examined over the catalysts. In iso-butene oxidation, acetic acid and 2-methyl maleic anhydride were detected but not maleic anhydride. In cyclohexene oxidation, benzene and phenol were detected as major products but it was not the case in cyclohexane oxidation. The results of our investigation indicate that the oxidation pathway of iso-butane is different from that of iso-butene, 2-methyl-1-propanol, tert-butanol, and 2-methylacrylic acid, whereas the oxidation pathway of cyclohexane is different from that of cyclohexene.     

防锈颜料的研究与应用展望

介绍了防锈颜料的基本分类和一些重要的新型低毒、无毒防锈颜料的防锈机理以及发展概况．讨论了各自应用和搭配使用问题及防锈颜料的发展趋势。     

船体防锈防污涂料体系配套与检测

船体防锈防污涂料体系是船舶涂料中最重要的体系之一。介绍了目前市场上几种防锈涂料及防污涂料,以及防锈防污涂料的主流产品及发展方向。阐述了与不同的防锈防污周期及应用对象相适应的配套产品,并介绍其主要的检测方法。     

水乳性防锈涂料的制备

介绍了一种水乳性防锈涂料的制备,以废弃的聚苯乙烯泡沫改性制得基料。再添加锈颜料,填料,乳化剂及助剂,并对该涂料的性能指标进行了测试。     

和谐机车膨胀水箱防锈工艺研究

介绍了和谐机车膨胀水箱防锈要求,采用乳化型水溶性防锈剂能够满足零件表面在有水和潮湿状态下的防锈要求,重点介绍了防锈工艺流程。     

Protected by Fumigants: Beetle Perfumes in Antimicrobial Defense

Beetles share with other eukaryotes an innate immune system that mediates endogenous defense against pathogens. In addition, larvae of some taxa produce fluid exocrine secretions that contain antimicrobial compounds. In this paper, we provide evidence that larvae of the brassy willow leaf beetle Phratora vitellinae constitutively release volatile glandular secretions that combat pathogens in their microenvironment. We identified salicylaldehyde as the major component of their enveloping perfume cloud, which is emitted by furrow-shaped openings of larval glandular reservoirs and which inhibits in vitro the growth of the bacterial entomopathogen Bacillus thuringiensis. The suggested role of salicylaldehyde as a fumigant in exogenous antimicrobial defense was confirmed in vivo by its removal from glandular reservoirs. This resulted in an enhanced susceptibility of the larvae to infection with the fungal entomopathogens Beauveria bassiana and Metarhizium anisopliae. Consequently, we established the hypothesis that antimicrobial defense in beetles can be expanded beyond innate immunity to include external disinfection of their microenvironment, and we report for the first time the contribution of fumigants to antimicrobial defense in animals.