Super acid catalyzed dimerization of fatty acids derived from safflower oil and dehydrated castor oil

Dimerization of fatty acids derived from dehydrated castor oil and safflower oil was carried out on the recently described sulphate-treated zirconia catalyst and trifluoromethane sulphonic acid (triflic acid) under autogeneous pressure in the temperature range of 160–240 C. Triflic acid was observed to be highly active; however, the product obtained was deeply colored. Zirconia exhibited high activity for the reaction. The important features of this catalyst were the high selectivity for dimer (low yields of trimer) and no significant coloration of the products. The zirconia catalyst shows promise for industrial use.     

蓖麻油硫酸氢钾催化脱水研究

考察了若干种酸性催化剂对蓖麻油脱水的影响。重点以硫酸氢钾为催化剂,在0.083 MPa真空度下对蓖麻油催化脱水进行了研究。利用正交实验考察了反应温度、反应时间、催化剂用量对脱水反应的影响。得出的最佳工艺条件为:反应温度250℃、反应时间70 m in、催化剂用量1.0%。在该工艺条件下制得的脱水蓖麻油平均碘值可达136,且粘度较小色泽较浅。     

Benzyl ester of dehydrated castor oil fatty acid as plasticizer for poly(vinyl chloride)

The poly(vinyl chloride) (PVC) industry plays an important role in today's total plastics industry. The major volume of PVC is used as soft and plasticized PVC. PVC applications consume approximately 80% of the total production of plasticizers. Most of the common plasticizers are aromatic esters of phthalic acid. In the majority of countries, phthalate plasticizers are banned due to their carcinogenic properties. The concern raised about toxicity led to a large demand for bio‐based non‐toxic plasticizers. Hence, there is an increasing interest in replacing the phthalate plasticizers with those produced from simple bio‐based materials. Dehydrated castor oil fatty acid (DCOFA) is a renewable resource which can be esterified and used as an environment friendly plasticizer for PVC. Benzyl ester (BE) was prepared by reacting DCOFA with benzyl alcohol in the presence of catalyst at 170–180 °C. Esterification was further confirmed by acid value, hydroxyl number, ¹H NMR and Fourier transform IR spectroscopy. The modified plasticizer was used in various proportions as a co‐plasticizer in PVC for partial replacement of dioctyl phthalate (DOP). With an increase in the proportion of BE in PVC samples, a good plasticizing performance was observed. The incorporation of BE also resulted in a reduction in viscosity and viscosity pick‐up and improved mechanical, exudation, thermal degradation and chemical resistance properties. The presence of BE showed a reduction in the whiteness index due to presence of conjugated double bonds in the structure. The results of DSC, XRD and Shore hardness studies showed no significant variation in properties compared with those of DOP‐plasticized sheets and thus we can conclude that BE can be used as a co‐plasticizer in PVC. © 2013 Society of Chemical Industry     

以亚磷酸二乙酯为第三组分的铁系催化体系催化异戊二烯聚合

以乙酰丙酮铁(简称Fe)/三异丁基铝(简称Al)/亚磷酸二烷基酯(简称DP)为催化体系,对异戊二烯进行聚合,考察了不同DP(烷基为甲基、乙基、正丁基或异辛基)、催化剂组成及反应条件对聚合的影响。结果表明,以亚磷酸二乙酯(DEP)为第三组分的催化体系,在己烷中于相对较高温度(50℃)下的催化活性最高。催化剂最佳配比为Al/Fe(摩尔比)15,DEP/Fe(摩尔比)2．0。所得聚异戊二烯橡胶的3,4-结构(含1,2-结构)摩尔分数约为60％,微观结构基本不受反应条件的影响。     

Characterization of fatty acid isomers in dehydrated castor oil by gas chromatography and gas chromatography-mass spectrometry techniques

Fatty acid isomers present in dehydrated castor oil were analyzed by gas chromatography and gas chromatography-mass spectrometry (GC-MS) of their dimethyl oxazoline derivatives. Conjugated linoleic acid 9,11 and 10,12 isomers were identified by GC based on equivalent chainlengths. Segmental peak analysis of GC-MS total ion chromatogram mass fragmentation pattern revealed the presence of 7,9 and 8,10 conjugated linoleic acids along with 9,11 and 10,12 conjugated linoleic acids. Interestingly, a reverse elution of trans,trans-conjugated linoleic acids was observed, viz. 10,12 was followed by 9,11, which was in turn followed by the 8,10 and 7,9 isomers. The observed reverse order of elution was in contrast to the conventional elution pattern of both nonconjugated and conjugated cis,cis-, cis,trans- and trans,cis-isomers.     

Polymerization of N‐phenylmaleimide with a rare‐earth coordination catalyst

The polymerization of N‐phenylmaleimide was carried out with the binary rare‐earth coordination catalyst lanthanum phosphonate [La(P₅₀₇)]–trisobutyl aluminum [Al(i‐Bu)₃] in toluene at 60°C. The dependence of the polymerization on the polymerization time, the molar ratio of Al(i‐Bu)₃ to La(P₅₀₇), and the concentration of the catalyst were studied. The structures of the resultant polymer were characterized with ¹H‐NMR, ¹³C‐NMR, and Fourier transform infrared spectrophotometry, and the thermal properties of the polymer were measured with thermogravimetric analysis. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 979–982, 2005     

Copolymerization of dehydrated castor oil with styrene: Determination of reactivity ratios

Dehydrated castor oil (DCO) has been used as a comonomer with styrene to determine reactivity ratios. The polymerization was a free-radical process in benzene, and the product was isolated by evaporation of the reaction mixture and by two precipitations into petroleum ether from benzene. The copolymer composition was determined by a saponification procedure. DCO was found to have a high chain transfer constant and a very low reactivity ratio (estimated at 0.086) compared to styrene (11.6). It was found that copolymerization is difficult to achieve in a system where the DCO concentration in the reaction mixture was above 20 mole-%.     

Miscibility behavior of blend of polyesteramides of linseed oil and dehydrated castor oil with poly(methacrylic acid)

Blending of two polymers in solution is a simple and cost‐effective technique to improve upon the physical and mechanical properties of the component polymers through synergism. To obtain maximum synergy in their properties, the component polymers should be miscible with each other on molecular scale. Polymer blends of complex physicomechanical properties are being actively investigated. Poly(methacrylic acid) (PMAA), a commercial polymer, yields transparent, hard, brittle, and water‐sensitive films. It has been blended with natural polymers like dextran, collagen, and gelatin to obtain films with improved physical and mechanical characteristics. Polyesteramides, which are easily synthesized from vegetable seeds oil, a sustainable resource, have found application in surface coatings. These oligomeric products do not make free standing films in the ambient condition. The polyesteramides from vegetable seeds oil can be used to obtain blend with PMMA of improved mechanical and water absorption properties. In this study, linseed oil polyesteramide (LOPEA) and dehydrated castor oil polyesteramide (DCPEA), the source oils with different unsaturation in their fatty acid chains, were blended with PMAA through mixing in solution in the ratio DCPEA/LOPEA: PMAA as 80/20, 70/30, 60/40, 50/50, 40/60, 30/70, and 20/80. In the first instance, the miscibility of the two components was investigated in solution by viscosity and ultrasonic measurements and in solid phase through differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Moisture absorption by the blend was also studied. DCPEA and LOPEA show immiscibility with PMAA in solution phase while LOPEA with more unsaturation in the fatty acid chain of the oil was found more immiscible than DCPEA. DCPEA shows a narrow miscibility window in the solid phase while LOPEA was found immiscible with PMAA in the solid phase too. Uptake of moisture was found to be markedly reduced in the blends of DCPEA/LOPEA with PMAA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1367–1374, 2007:     

Composition of fatty acids obtained by decomposition of castor oil fatty acid estolides

The composition (wt %) of the fatty acids obtained by decomposition of castor oil fatty acid estolides and distillation was determined by a combination of spectroscopic (ultraviolet, nuclear magnetic resonance, infrared), chromatographic (thin layer on Silica Gel G modified with silver nitrate and ammonium hydroxide, gas liquid) and chemical (partial reduction and periodate/permanganate oxidation) techniques and found to be 16:0, 2.7; 18:0, 2.6; 18:1, 5.2; conjugatedcis,trans (trans,cis)-18:2, 34.4; conjugatedcis,cis-18:2, 9.7; conjugatedtrans,trans-18:2, 3.9; 9-cis,12-trans-18:2, 20.8; 9-trans,12-cis-18:2, 2.3; and 9-cis,-18:2, 18.4.     

Polymerization kinetics of styrene using coordination catalysts containing rare earth compounds

Polymerization reactions of styrene in toluene at 60°C have been carried out using Ziegler–Natta catalysts containing praseodymium trichloroacetate‐triethyl aluminum [Pr(OCOCCl₃)₃‐Et₃Al] (system I) and praseodymium trichloroacetate‐diethyl aluminum bromide [Pr(OCOCCl₃)₃‐Et₂AlBr] (system II). The reaction was of first order with respect to both monomer and catalyst concentrations. At a stoichiometric ratio of Al/Pr = 8, an optimum catalytic activity was observed. The activation energies for systems I and II ranged between 21.06 kJ/mol and 13.79 kJ/mol, respectively. System I was white in color and system II is waxy. Molar masses of systems I and II were 9.1 × 10⁵ and 2.2 × 10⁴, respectively. The polymers were characterized by viscometry and ¹H NMR methods. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 995–1002, 2001     

蓖麻油磷酸催化脱水研究

以H3PO4为催化剂,在减压下对蓖麻油催化脱水进行了研究。利用正交实验考察了反应温度、反应时间、催化剂用量、真空度对脱水反应的影响。得出的最佳工艺条件为:反应温度250℃、反应时间90min、催化剂用量1.0%、真空度600×133.3Pa。在该工艺条件下制得的脱水蓖麻油平均碘值达到138,且色泽较浅。     

磺化蓖麻油酸的合成

以浓硫酸磺化蓖麻油酸,得到磺化蓖麻油酸,具有良好的乳化力和渗透力,可作为阴离子表面活性剂,用正交实验优化了磺化反应的工艺条件。结果表明,最佳工艺条件为:n(蓖麻油酸)∶n(浓硫酸)=1∶2,反应温度50℃,反应时间6h。由方差分析和极差分析可知,物料配比n(蓖麻油酸)∶n(浓硫酸)对反应的影响极其显著,其次是反应时间,温度对反应的影响最小。在最优条件下,磺化率可达30%以上,25℃下,粘度>380mPa.s,固含量>80%,产品性能稳定。通过傅立叶红外光谱法、1H NMR、元素分析法、化学分析等鉴定,对合格产品分析可知,得到的磺化蓖麻油酸为高度磺化产品。     

稀土催化剂抗酸性镀锡液氧化变质的研究

酸性镀锡液稳定性差,易氧化变质。探讨了酸性镀锡液产生氧化变质的机理。在镀锡液中加入0．05－0．1g/L稀土催化剂,通过加速氧化试验和空气暴露试验研究镀锡液的稳定性。结果表明：镀液稳定性显著提高。     

杂多酸催化剂走向分子设计

从分子设计的角度讨论了杂多酸的结构与催化性能、制备方法以及在有机合成、石油化工中的应用进展。     

Studies on miscibility of dehydrated castor oil epoxy blend with poly(methyl methacrylate)

Oil epoxies can be used as plasticizers in the processing of hard polymers. For this purpose dehydrated castor oil epoxy (DCOE), a product from sustainable resource, has been chosen for blending with poly(methyl methacrylate) (PMMA) to investigate the compatibility of this blend pair. Blends of DCOE/PMMA were prepared in the weight ratios 80/20, 60/40, 40/60, and 20/80 through solution method by mixing in dimethylsulphoxide. Free‐standing films of the blend were cast and the miscibility of the two components was investigated by viscosity and ultrasonic measurements, which provided valuable information on the degree of compatibility of the pairs of blends in solution. The compatibility was also examined by differential scanning calorimetry and scanning electron microscopy. All the studies revealed that DCOE was immiscible with PMMA. However, the appearance and texture of the films were not found to show any visible change over several months, which indicates stability of this blend system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3094–3100, 2006     

Ethylene Polymerization under high pressure and temperature using Nickel-α-diimine catalyst

The combination of 1,4–bis(2,6-diisopropylphenyl)-acenaphthenediimine-dichloronickel (II) (1) and methylaluminoxane (MAO) has been shown as being highly active in ethylene polymerization under high pressure and temperature. Herein we describe the effects of ethylene pressure and reaction temperature on polymer properties and reaction performance. The polyethylenes synthesized with the system 1/MAO are highly branched, with 105 to 277 branches per 1000 backbone carbon atoms, depending on the reaction conditions. The branching index increases with the rise of temperature or with the decrease of ethylene pressure. These branches go from methyl to hexyl, or even farther, and present a pattern in which 1,4; 1,5 and 1,6 methyl groups appear mainly and isolated methyl groups are not present. These branches are generated by a chain-walking system. The polyethylenes produced with these systems have a molecular weight (Mw) between 44,000 and 105,000 Daltons and polydispersions from 2,0 to 4,0, depending on reaction conditions. The polymer molecular weight tends to decrease with the increasing temperature of polymerization.     

Polymerization studies using modified Ziegler-Natta catalysts: 3. The catalyst system

The catalyst system VOCl₃/Al(iBu)₃/THF has been examined and the role of the individual catalyst components investigated. Tetrahydrofuran is believed to undergo complex formation with the other catalyst components thus restricting reduction of the vanadium to V(IV). The complex VOCl₂.2THF has been isolated and, when used with tri-isobutyl-aluminium in the presence of excess tetrahydrofuran, shown to produce polymerization systems of comparable activity to the VOCl₃/Al(iBu)₃/THF systems. The kinetic behaviour of the VOCl₃/Al(iBu)₃/THF system has been investigated and shown to be consistent with a simple Ziegler-Natta kinetic scheme involving a rapid bimolecular decomposition of either a transition metal alkyl compound, or of a complex formed on interaction of a transition metal alkyl with an aluminium alkyl.     

Sulfonylation of aromatic compounds with sulfonic acids using silica gel-supported AlCl3 as a heterogeneous Lewis acid catalyst

Silica gel-supported aluminum chloride (SiO₂–AlCl₃) has been shown to be a mild, efficient, and chemoselective heterogeneous Lewis acid catalyst for direct conversion of arenes to sulfones using sulfonic acids as sulfonylating agents. The catalyst can be prepared easily with cheap starting materials and is stable (as a bench-top catalyst) and reusable.     

Polymerization of norbornene using novel palladium carboxylate/boron trifluoride etherate catalyst system

The vinyl polymerization of norbornene with Pd(carboxylate)₂/BF₃OEt₂ catalyst system has been investigated by varying the molar cocatalyst/metal ratio, the norbornene/metal ratio, the metal concentration and the reaction temperature. The effects on the catalyst activity were explained on the basis of complexation equilibrium for the active homogeneous complex. A “particular” activity of 154 100 kg NB per mole Pd for an hour has been achieved at B/Pd = 25 and 25 °C. The molecular weights M_w from 77 700 to 293 800 g/mol and glass transition temperatures T_g from 240 to 262 °C were observed for the representative samples of polynorbornene. The molar mass distribution indicates a single-site, highly homogeneous character of the active catalyst species. Catalytic activity and polymer molecular weight can be controlled by varying the reaction parameters over a wide range. NMR and IR spectroscopic studies of the polymer showed 2,3-enchained repeating units of polymer backbone with low diisotacticity. The simplicity of catalyst system composition might be of industrial importance.