Surfactant properties and biodegradation of polyethoxylates from phenolic lipids

The surface tension of aqueous solutions of cardanol and cardol polyethoxylates derived from technical cashew nut-shell liquid were examined to determine their relative surfactancy. The compositions with the greatest surface tension reduction, or optimal surfactancy, were selected for biodegradation testing, in terms of total organic carbon, using a soil inoculum. The experimental surfactants in this study were compared with commercial t-nonyl polyethoxylate and glucose as reference materials. Over a period of 28 d, cardanol polyethoxylate and its saturated analog were degraded to 17 and 25%, respectively, and cardol polyethoxylate and its saturated analog were degraded approximately half that extent (37 and 46%). t-Nonylphenyl polyethoxylate remained substantially undegraded (77%), whereas glucose was almost completely degraded (5%).     

Synthesis and characterization of new cationic surfactants derived from lactic acid

A series of new cationic surfactants was prepared by condensation of lactic acid with N,N-dimethyl propylamine, followed successively by acetylation with acid chloride or ester and by quaternization with dimethylsulfate. Each surfactant and its precursors' structural assignments were based on infrared spectra and ¹H and ¹³C nuclear magnetic resonance spectra. Critical micelle concentrations, contact angles, kinetics of drop spreading, and foam capacities were determined.     

壬基酚衍生的季铵盐阳离子表面活性剂的合成及性能

利用环氧氯丙烷和三乙胺分别与壬基酚、壬基酚聚氧乙烯醚 (n =4)反应 ,合成了 (2 -羟基 -3 -壬苯基 )丙基三乙基氯化铵 (1)和 (2 -羟基 -3 -壬苯基聚氧乙烯基 )丙基三乙基氯化铵 (2 )新型阳离子表面活性剂。化合物 (1)和 (2 )的γcmc 分别为 3 1 2 0mN/m、 3 3 47mN/m ,cmc分别为3 16× 10 -4mol/dm3 和 2 0 3× 10 -4mol/dm3 ,具有良好的絮凝能力。     

Synthesis and characterization of cleavable surfactants derived from poly(ethylene glycol) monomethyl ether

A series of noncyclic acetal-linked cleavable surfactants were simply prepared by condensation of aldehydes with poly(ethylene glycol) monomethyl ethers. All of the products were characterized by¹H nuclear magnetic resonance. Their hydrophile-lipophile balance, surface tension, cloud point, critical micelle concentration, and foam height were determined. Hydrolysis kinetic studies, followed by gas chromatography, showed that they had higher hydrolytic reactivity in acidic solution than cyclic acetal-linked cleavable surfactants.     

Synthesis and surface measurements of surfactants derived from dehydroabietic acid

Dehydroabietates with poly(ethylene oxide) chains of average m=12, 17, and 45 units [DeHab(E) _m ] were synthesized. The adsorption at the liquid-vapor interface was measured, and the adsorbed amount and critical micelle concentrations (CMC) were determined. The foamability, the foam stability, wetting properties, and cloud points, with and without salt content, were studied. The results were compared with common linear alkyl ethoxylates, nonylphenol ethoxylates, and cholesterol ethoxylates. The dehydroabietic acid as hydrophobe was found to result in the same CMC as a linear dodecyl chain. DeHab(E)₄₅ was found to be insoluble above 400 mg/L, but the surface tensions at lower concentrations were similar to those of the C_11–13E_38–40 surfactants, which exhibit CMC in aqueous media. The foaming behavior of the DeHab(E)₁₂ and DeHab(E)₁₇ surfactants was about the same as for common linear C _n E _m surfactants. The foamability as well as the foam stability increased with ethylene oxide (EO) chain length. The cloud point was depressed by increased salt concentration and increased with the number of EO units in the head group. The cloud point was significantly lower than for the corresponding surfactant with a dodecyl chain with similar EO chain length. The wetting results, obtained by measuring the contact angle at similar surface tensions, indicate that surfactants of the DeHab(E) _m type are more efficient wetting agents than both disaccharide sugar surfactants and C _n E _m type surfactants.     

Synthesis and characterization of imidazolinium surfactants derived from tallow fatty acids and diethylenetriamine

This paper describes the synthesis of long‐chain dialkylamido imidazolines based on tallow fatty acids and diethylenetriamine, followed by their quaternization. Imidazolines were obtained by non‐solvent microwave synthesis using calcium oxide as support, which were then quaternized by using dimethyl sulfate as a quaternizing agent and iso‐propanol as a solvent, to produce cationic imidazolinium salts. The synthesized cationic imidazoline surfactants were evaluated for yield and cationic content. The instrumental techniques, viz. FT‐IR and ¹H‐NMR, verified the formation of imidazolines and their subsequent quaternization. The surface‐active and performance properties of the cationic imidazolines in terms of critical micelle concentration, surface tension, dispersibility, emulsion stability, softening, rewettability and antistatic properties were also reported.     

环氧乙烷/四氢呋喃共聚醚的合成与表征

用杂多酸(HPA)引发环氧乙烷(EO)与四氢呋喃(THF)发生共聚反应,从而制得了EO-THF共聚醚[P(EO-THF)]。用红外光谱(FT-IR)、核磁共振(1H NMR)、凝胶渗透色谱-多角度激光散射仪(SEC/MALLS)和差示扫描量热仪(DSC)等仪器对P(EO-THF)的结构进行了表征,并对其聚合机理进行了分析。实验结果表明,HPA作为引发剂可用来制备相对分子质量分布指数小于1.4、平均官能度为2的P(EO-THF);P(EO-THF)的熔点受单体投料比影响较大,当n(EO)∶n(THF)=1∶1时,产物的熔点最低(为-14.28℃);在共聚反应过程中,THF的浓度对共聚反应速率及P(EO-THF)的相对分子质量影响显著,当THF的浓度小于1.39 mol/L时,共聚反应速率较低。     

聚天冬氨酸的合成与表征

介绍了以L -天冬氨酸为原料 ,热缩合成聚天冬氨酸酐 ,水解得到聚天冬氨酸的合成工艺。采用凝胶色谱法测定了聚天冬氨酸的分子量 ,并用核磁共振对其进行了表征。     

Synthesis and characterization of thiol‐terminated poly(ethylene oxide) for chemisorption to gold surface

Thiol‐terminated poly(ethylene oxide) (PEO) was synthesized using two different approaches: esterification of terminal hydroxyl groups with mercaptoacetic acid and amidation using N‐hydroxysuccinimidyl PEO (NHS–PEO) and cysteine. The reaction of hydroxyl‐terminated PEO with mercaptoacetic acid was carried out in boiling toluene. Different thiolated PEOs, including linear PEOs of varying molecular weights and end‐group types, and star‐type PEOs were synthesized. Nuclear magnetic resonance and infrared spectroscopy were used to characterize the products. The reaction kinetics were also briefly investigated. Gel permeation chromatography was used to investigate the relative amounts of the mono‐ and disubstituted products in the α,ω‐dihydroxy PEOs. NHS–PEO was used both to attach terminal thiol groups via reaction with cysteine and to conjugate other amino acids (and potentially any amino‐containing molecule) to PEO. Reactions using NHS–PEO were carried out at room temperature in water. The chemisorption of these thiolated PEOs to gold was expected to yield surfaces resistant to biofouling, in particular to unwanted protein adsorption. Chemisorption of amino acid–, peptide‐, or protein‐terminated PEOs in addition may yield surfaces having specific biological activity. Work on these aspects will be reported elsewhere. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 594–607, 2003     

Antioxidant activity of lipid-soluble phenolic diterpenes from rosemary

A high-performance liquid chromatography method for analyzing the phenolic diterpenes present in rosemary (Rosmarinus officinalis L.) and commercial rosemary extracts is reported. Carnosic acid was the major phenolic diterpene present in rosemary leaves, with lesser amounts of 12-methoxycarnosic acid and carnosol. Several commercial rosemary extracts also were analyzed by this method, and in addition to these three compounds other phenolic diterpenes, such as 7-methoxyrosmanol, 7-methoxy-epirosmanol, and rosmanol, were found in some samples. These latter three compounds seem to be artifacts, produced from carnosic acid by oxidation and cyclization. The major phenolic diterpenes were isolated, and their relative antioxidatn activities in soybean oil were measured by the Rancimat. The potency of carnosic acid was more than twice that of any other compound. The antioxidant activity of pure carnosic acid was compared to butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and tertiary butylhydroquinone (TBHQ) and was several times greater than BHT and BHA but less than TBHQ. Nuclear magnetic resonance data for several of the compounds that were incompletely characterized in previous literature are reported.     

N-12-羟基硬脂酰氨基酸型表面活性剂的合成与表征

以12-羟基硬脂酸和3种不同类型的天然氨基酸为原料,采用N,N′-二环己基碳酰亚胺(DCC)和N-羟基丁二酰亚胺(NHS)作为偶合剂,合成了3种具有代表性的N-12-羟基硬脂酰氨基酸(酸性、中性和碱性)表面活性剂。首先,12-羟基硬脂酸和N-羟基丁二酰亚胺反应制得N-羟基琥珀酰亚胺12-羟基硬脂酸酯(产率85%以上),然后将后者与氨基酸进行缩合反应得到了N-12-羟基硬脂酰氨基酸表面活性剂。其较佳合成工艺条件为:N-羟基琥珀酰亚胺12-羟基硬脂酸酯与氨基酸摩尔比为1∶1,室温反应,反应时间不少于4 h,以丙酮与水体积比1∶1为混合溶剂,产率达到80%。利用IR、元素分析和1HNMR对所得产物进行表征,确定了产物结构。     

Physico-chemical properties of heavy crude oil-in-water emulsions stabilized by mixtures of ionic and non-ionic ethoxylated nonylphenol surfactants and medium chain alcohols

This work describes the formulation and evaluation of concentrated, heavy oil-in-water emulsions stabilized by mixtures of ethoxylated surfactants and normal alcohols. The rheology, stability and droplet size of these emulsions were investigated as functions of the emulsification process parameters. The parameters investigated for this study include emulsifier agent composition, presence of additives, pH and salinity of the continuous aqueous phase, emulsification temperature, oil content and emulsion aging. The produced emulsions had viscosities ranging from 30 to 150 mPa s and represent a 30-fold reduction of the crude oil viscosity. Sauter mean diameters of the droplets ranged from 10 to 50 μm. The emulsions were produced by mixing the oil with an aqueous solution containing medium normal-chain alcohols and small quantities of a mixture of ethoxylated nonylphenol and ethoxylated amine surfactants. The presence of these alcohols led to a sharp decrease in the droplet size of the emulsion. This size decrease had a direct impact on the emulsions’ stability and apparent viscosity. The rheological parameters of the aged emulsions were also essentially constant over a 42-day period.     

酒石酸衍生手性荧光聚合物的合成及表征

以对映纯酒石酸为碳源,在油酸介质中通过溶剂热法一步合成了荧光聚合物。制备的荧光聚合物水溶性好、发光稳定,未经钝化处理荧光量子产率可达4.02%。圆二色光谱分析表明,荧光聚合物具有手性特征。利用元素分析、光电子能谱、质谱等对手性荧光聚合物进行了表征。荧光聚合物的合成方法简单方便,易放大,产率高。     

糠醛缩邻氨基苯甲酸Schiff碱稀土配合物的合成与表征

合成了糠醛缩邻氨基苯甲酸Schiff碱及其4种稀土配合物,并通过元素分析、IR、UV、1H NMR和热失重分析对其组成和结构进行表征,结果表明,配体是以四齿的形式参与配位,配位数为8,配合物的组成为Re(L)2.2.5H2O(Re=Eu、Sm、La、Y)。     

Synthesis, purification, and characterization of structured lipids produced from chicken fat

A structured lipid (SL) was synthesized enzymatically from chicken fat by incorporating a medium-chain length fatty acid (caprylic acid) into chicken fat triacylglycerols. Carica papaya latex was used as the biocatalyst. The optimal substrate mole ratio found was 1∶2 (chicken fat fatty acids/caprylic acid). At this ratio of reactants, the incorporation of caprylic acid (C_8∶0) at 65°C was 23.4 mol%, whereas at 55°C the incorporation of caprylic acid was 17.6 mol%. A packed-bed column bioreactor was designed for the synthesis of SL from chicken fat. In using ground crude C. papaya latex (a _w <0.1), 7.1 mol% of caprylic acid was incorporated into the chicken fat triacylglycerols after 117 min of reactor residence time. After purification of the SL, the acyl positional distribution of fatty acids on the glycerol backbone was determined by ¹³C nuclear magnetic resonance (NMR) spectroscopy. From the NMR spectrum of the SL, it was determined that saturated fatty acyl residues at the 1,3-positions of the SL triacylglycerols increased to 62% over that of the starting chicken fat triacylglycerols, suggesting that caprylic acid was preferentially incorporated at the 1,3-positions. In addition, differential scanning calorimetry thermograms were obtained to compare the crystallization characteristics of the starting chicken fat with the SL prepared from it. This work was presented at the Biocatalysis Symposium in April 2000, held at the 91st Annual Meeting and Expo of the American Oil Chemists Society, San Diego, CA.     

Synthesis and characterization of polymers derived from selenophene

The synthesis of poly(2,5‐selenophen‐oxo‐1,4‐phenylen‐selenide‐1,4‐phenylene‐oxo) (I) and poly(2,5‐selenophen‐oxo‐1,4‐phenylen‐diselenide‐1,4‐phenylen‐oxo) (II) by reaction of 2,5‐bis(1,4‐bromo‐phenylen‐oxo‐)‐selenophene with sodium selenide or diselenide, respectively, using dimethylformamide as solvent, is described. Both monomers and polymers were characterized by elemental analysis, melting point, and FTIR spectroscopy. Polymers I and II were doped with iodine and SbF₅ and characterized by SEM and XPS. Also, the conductivity and the T_g values were determined. For both polymers the best doping agent was iodine, although polymer II always presented higher conductivity, reaching values of about 6 · 10^?9 S · cm^?1. The T_g values suggest a likely crosslinking of the chains in polymer II when doped with SbF₅. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2019–2026, 2001     

Synthesis,characterization, and surface properties of phenylalanine-glycerol ether surfactants

A novel homologous series of 1-N-l-phenylalanine-glycerol ether surfactants was synthesized in satisfactory yields via reaction of epichlorohydrin with aliphatic alcohols with alkyl chains of 10–15 carbon atoms. Structural assignment of the new compounds was made on the basis of elemental analysis and spectroscopic data. Critical micelle concentration (CMC), surface tension at the CMC (γ_CMC), surfactant concentration required to reduce the surface tension of the solvent by 20 mN/m (pC₂₀), and the interfacial area occupied by the surfactant molecules (A_min) were determined from aqueous surface tension measurements using the Wilhelmy plate technique.     

Synthesis and characterization of poly(esteramide‐urethane) from linseed oil as anticorrosive coatings

Ethylene diamine polyesteramide (Ed‐PEA) was synthesized from N, N‐bis (2‐hydroxy ethyl) linseed oil fattyamide and ethylene diamine tetra acetic acid through condensation polymerization. It was further treated with toluylene 2,4‐diisocyanate (TDI) in different weight percentage to obtain urethane‐modified polyesteramide (Ed‐UPEA). The structural elucidation of Ed‐PEA and Ed‐UPEA were carried out by FTIR, ¹H‐NMR, and ¹³C‐NMR spectroscopic techniques. Thermal studies of these resins were carried by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The coatings of urethane‐modified polyesteramide were prepared on mild steel strips and their anticorrosive behavior of in acid, alkali, water, and xylene were investigated. Thermal stability performance suggests that the system could be safely used upto 200°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of lactobionic acid grafted pegylated chitosan and nanoparticle complex application

A series of chemical modifications of chitosan were conducted by grafting a hydrophilic methoxy poly(ethylene glycol) (MPEG) and a target sugar molecule lactobionic acid (LA). The MPEG was grafted onto C6-OH position of chitosan, and the grafting degree was reduced for chitosan with high degree of depolymerization. The lactobionic acid was proposed to graft onto C2-NH₂ position of chitosan. The LA grafting ratio was dependent on pegylation degree of chitosan, where the flexibility and shielding effect of MPEG hindered LA grafting onto chitosan. The lactobionic acid grafted pegylated chitosan, DADP-CS-(O-MPEG)-(N-LA), successfully provoked DNA condensation into nanoparticle complexes due to electrostatic compaction. The presence of MPEG on DADP-CS-(O-MPEG)-(N-LA) played an important role on preventing nanoparticle aggregation.     

Synthesis and characterization of block-copolymer surfactants with specific interactions with associative thickeners

It has been theorized that, in order to get some positive interaction with the associative thickeners, the surfactants should have, at the end of the hydrophilic sequence, a short hydrophobic group. On the other hand, in order to control the hydrophilic lipophilic balance (HLB), it is wise to use well controlled polymerization procedures to build the block-copolymer. Then, the safer and simplest way to reach such goal is to use the ring-opening living anionic polymerization of butylene oxide (hydrophobic sequence) and then ethylene oxide (hydrophilic sequence); this living block-copolymer is then killed using an alkyl or aryl chloride (or bromide). However, because such surfactants include at the end of the hydrophilic sequence a hydrophobic group, they tend to adopt, when adsorbed onto hydrophobic latex particles, a back-folded conformation. In order to get for them an extended conformation, the hydrophilic sequence should have charges able to repel each other. This was achieved upon preparing block-copolymers of acrylic acid and butylacrylate, using a controlled radical polymerization with reversible addition fragmentation transfer (RAFT) agents, starting with the poly(acrylic acid) (PAA) sequence. Then, the radical fragment coming from the RAFT agent is at the end of the PAA sequence. A few rheological data actually confirm the interest of the concept.